Application of wood sawdust microbial transformation for the utilization of long-term stored bark-wood waste

Application of wood sawdust microbial transformation for the utilization of long-term stored bark-wood waste | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Application of wood sawdust microbial transformation for the utilization of long-term stored bark-wood waste Ludmila Alexandrovna Belovezhets, Dmitry Sergeevich Belousov, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7628066/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 10 Apr, 2026 Read the published version in Biotechnology Letters → Version 1 posted 5 You are reading this latest preprint version Abstract The issue of bark-wood waste (BWW) utilization is challenging for the regions adjacent to pulp and paper mills. Bark is difficult to recycle, and the additives used in paper production further complicate this process. This work focuses on the potential application of wood sawdust microbial transformation, the technology of which was developed at the Irkutsk Institute of Chemistry SB RAS, for the processing of bark-wood waste into environmentally safe soil. Laboratory experiments revealed that long-term stored BWW can undergo microbial degradation. The best results were obtained with the BWW/sawdust mixture. The substrate neutralization conditions were selected to simultaneously lower the pH and introduce the necessary mineral additives for microbial function. A semi-industrial experiment with a BWW/sawdust mixture of 20 m 3 (3:1 ratio) was performed. The experiment demonstrated that pH stabilization occurred more efficiently than in the laboratory experiment. A temperature increase, which is characteristic of aerobic processing of lignocellulosic waste was also observed. The product obtained was non-toxic to both plants and Chlorella vulgaris (hazard class 5). The processing improved of the agrochemical parameters of the substrate, such as hydrolytic acidity, cation exchange capacity, and the sum of absorbed bases. The increase in humic acid content indicates a deep microbial degradation of the lignin component of BWW. Consequently, the microbial transformation of BWW was successfully implemented to produce a non-toxic soil. This technology can be scaled up for large volumes of BWW at storage sites. bark-wood waste microbial processing soil composting parameters Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction The volume of wood harvested worldwide is large (3.91 billion m 3 in 2022) and is increasing annually by an average of 0.8% (State report 2023). Owing to the long-term activity of large wood processing enterprises, environmental pollution has become a biosphere-wide process. In Russia, no more than half of the biomass of harvested wood is used sustainably. Consequently, wood processing enterprises generate approximately 68–74 million m 3 of wood waste annually, of which only 48–58% is processed. One of the main types of sawmill waste is bark, which accounts for 8–15% of the waste structure. Due to its complex chemical and mechanical structure, bark is not widely used in secondary processing (Petrunina et al. 2022 ). The only industrial application of conifer bark is in the landscape, agrotechnical and design works to mulch the soil and improve the aesthetic appearance of parks (Hallman et al. 2023 ). The microbial decomposition of bark is a slow process due to its high antibacterial and disinfectant contents (Janah et al. 2025 ; Dessalegn et al. 2025 ; Hazizah et al. 2025 ; Hossain et al. 2024 ). Bark-wood waste (BWW) accumulates in large quantities in pulp and paper mill dumps (Kulikova et al. 2022 ). This waste is almost not involved in further utilization. This leads to the formation of environmental disaster zones in the areas surrounding pulp and paper mills due to the toxic effects of BWW components on soil and groundwater. The inconsistent composition and the presence of hard-to-degrade polymers in BWW make it extremely unfavorable substrate for chemical and thermal utilization. Moreover, long-term stored BWW can undergo microbial processing to produce fungal enzymes (Martynov et al. 2024 ) and even composting (Margina et al. 2023 ). A method for the microbial processing of sawmill waste into organic-mineral fertilizer was developed at the Irkutsk Institute of Chemistry (Belovezhets 2019 ). This work aimed to investigate the potential application of this technology to process bark-wood waste into environmentally safe soil. Materials and methods Long-term stored BWW from Bratsk Pulp and Paper Mill (elemental composition: C 18.01, H 2.29, P 0.45, N 0.0, S 0.0, ash 45.51, lignin 37.0, cellulose 28.0, pH 9.4) and fresh softwood sawdust (elemental composition: C 17.84, H 6.17, P 0.3, N 0.03, S 0.61, ash 3.68, lignin 31.3, cellulose 47.3, pH 4.5) were used as substrates. Elemental analysis was performed automatically on a Flash EA 1112 CHN-O/MAS 200 microanalyzer. The moisture content was determined on a moisture meter AND MX-50 (Japan), and the pH was determined on a pH-meter Expert-pH (“Econix” Russia) according to GOST 26423-85 (Interstate standard of the USSR, 1986). The substrates were neutralized with 0.8% NH 4 NO 3 or a mixture of 4% HNO 3 and H 3 PO 4 . For the laboratory experiments, the following compositions were used: 1. BWW + association of microorganisms 2. BWW + association of microorganisms + sawdust Neutralized BWW without microorganisms served as the control. In all the cases, 4 liters of substrate, pre-neutralized and humidified to the optimum moisture content, were employed. The ratio of BWW/sawdust was 3:1. Microorganism cultures of Paecilomyces variotii sp ., Phanerochaete chrysosporium, Trametes versicolor, Sporotrichum pulverulentum (14B), and Sporotrichum pulverulentum (14G), which were isolated from infected wood in Eastern Siberia and identified on the basis of 26S-RNA in the All-Russian Collection of Industrial Microorganisms, were used in this study. One hour after acidification, a mixture of five-day-old fungal cultures grown individually (on modified Sabouraud's nutrient medium, under stationary conditions at 26°C) was added to the substrates. As neutralization was carried out using a mixture of nitric and phosphoric acids, mineral additives were not employed (Belovezhets 2019). Dilute acid solutions were prepared from the culture filtrate. The substrates were neutralized to a pH of 5.6–6.2. Modeling of real exothermic composting processes, which is impossible with a small substrate volume, was performed by incubation of the mixture in a thermostat at 37°C. The moisture content was maintained at 60–70%. The duration of the experiment was 5 months. Lignin loss was estimated gravimetrically after hydrolysis with 72% Н 2 SO 4 , and cellulose loss was evaluated indirectly by determining the amount of reducing substances in terms of glucose content via the phenol-sulfuric acid method (Yue et al. 2022). The mobile forms of nitrogen were determined according to GOST 27894.3–88 (State standard of the USSR 1988), phosphorus was determined according to GOST 27894.5–88 (State standard of the USSR 1988), and the cation exchange capacity (mEq/100 g) was determined according to GOST 17.4.4. 01–84 (Interstate standard of the USSR 1985), hydrolytic acidity (mEq/100 g) according to GOST 26212-91 (State standard of the USSR 1993), the sum of absorbed bases (mEq/100 g) according to GOST 27821-88 (State standard of the USSR 1990), the mass fraction of humic acids in terms of dry matter (%) according to GOST 9517-76 (State standard of the USSR 1977), and ash content according to GOST 11306 − 2013 (Interstate standard of the Russian Federation 2013). The phytotoxicity of the samples was established using the biotesting method on higher plant cress ( Lepidium sativum ) (Kubrina and Supinichenko 2021), and the toxicity of the aqueous extracts was determined via the use of green freshwater unicellular algae ( Chlorella vulgaris beijer ) according to GOST R 54496 − 2011 (National standard of the Russian Federation 2011). The semi-industrial experiment was carried out with the following substrates: BWW, 15 m 3 ; sawdust 5, m 3 (pH of the mixture was 8.5). The experiment was performed on 26.05.2024 at the site belonging to the A.E. Favorsky Irkutsk Institute of Chemistry of the Siberian Branch of the Russian Academy of Sciences, Russia, Irkutsk (geographic coordinates: 52°24' N 104°26' E). The site was preliminarily cleared from vegetation and leveled. The substrate was spread in an even 0.5 m-thick layer and subjected to neutralization with a 3:1 mixture of nitric and phosphoric acids. For neutralization, the acid was diluted with tap water to a concentration of 4%. The substrate was watered using a submersible pump (Vikhr VN-10N, Russia). Neutralization was carried out once. Microorganisms were grown individually (Belousov et al. 2024). Results The starting BWWs are highly toxic (hazard class 3.5), which makes them unsuitable for use as soil. This problem can be solved using the directed microbial transformation. It was hypothesized that the association of non-pathogenic basidial fungi employed for processing wood sawdust could also be effective for BWW utilization. To optimize the conditions for these fungi, one version of the laboratory experiment included a mixture of sawdust and BWW. Preliminary experiments revealed that BWW and sawdust have highly imbalanced elemental compositions. They are also characterized by high ash content and high pH values (BWW: 9.4; BWW/sawdust mixture: 8.5). Consequently, it was necessary to select an adequate neutralization option in the first stage of the laboratory experiment. As the optimum pH for fungal performance is 5.5–6.9, it was set to between 6.0 and 6.8 before the cultures were applied. Initially, 0.8% NH 4 NO 3 was used for neutralization. However, even when 25.7% of the total substrate volume was applied, the ammonium nitrate solution did not reduce the pH to the required level. Therefore, neutralization with a mixture of 4% HNO 3 and 4% H 3 PO 4 was performed. The results of the pH dynamics are presented in Table 1 . Table 1 Neutralization of BWW with 0.8% NH 4 NO 3 and a mixture of 4% HNO 3 and 4% H 3 PO 4 Content of NH 4 NO 3 , % vol. рН Content of HNO 3 and H 3 PO 4 , % vol. рН 0.0 9.4 0.00 9.4 1.4 8.4 0.26 6.9 4.4 8.0 0.53 6.6 8.2 7.7 0.70 6.6 10.8 7.6 0.93 6.6 15.1 7.5 1.00 6.6 19.3 7.5 1.13 6.5 25.7 7.4 Two days after the start of the experiment, the pH was 6.1 for the experimental samples and 7.1 for the control samples. However, owing to the high buffer capacity of the substrates, the pH began to shift toward the alkaline region one week after neutralization. To increase the pH above 7.2, the substrates used in the laboratory experiments were additionally acidified with a mixture of 0.5% HNO 3 and 0.5% H 3 PO 4 during watering. This low concentration was used to reduce the risk of adverse effects on microbial associations. Unfortunately, the pH of all the samples tended to increase. In the control samples, alkalinization of the medium occurred much faster reaching higher values. Watering with diluted acids was carried out twice a week. In all the experiments, the pH stabilized after two months (Fig. 1 ). Therefore, further acidification of the experimental samples was not carried out. During the third and fourth months of the experiment, the pH remained stable. In the room temperature experiments, the pH reached relatively high values during the first stage but stabilized at the level of the thermostated variants during the last month. This is most likely due to microorganisms being more active at elevated temperatures. Interestingly, the second wave of substrate alkalinization began in the fourth month of the experiment. Even in the experimental samples, the pH reached 8.1 (8.4 in the control) (Fig. 1 ). Moreover, the pH was higher in the thermostated samples than in the samples incubated at room temperature. Notably, the samples cultivated at elevated temperatures presented abundant fungal growth and a pronounced fungal odor, as observed visually one week after the start of the experiment. Similar results for samples grown at room temperature were noted only after two months. The toxicity class determined using Chlorella vulgaris (Table 2 ) increased in the thermostated samples in the middle of the experiment and decreased to the fifth class by the end of the third month. Moreover, the toxicity of the samples incubated at room temperature increased over time. These findings suggest that the observed effects are most likely attributable to delayed processing of compounds that are toxic to Chlorella vulgaris at room temperature. However, the toxicity level increased again by the fifth month of the experiment. This was attributed to an increase in substrate pH (according to preliminary experiments, alkalinization of the solution negatively affects the growth of Chlorella vulgaris ). Table 2 Toxicity class determined using Сhlorella vulgaris Variant Control BWW BWW/sawdust Incubation time R* T** R T R T 2 months 5 4.5 5 4 5 4 3 months 4 4 4 5 5 5 4 months 4 4 5 5 5 4.5 5 months 4 3.5 4 3.5 4 4 * R – samples incubated at room temperature, ** T – samples incubated at 37°C in a thermostat Loss of lignin and cellulose was observed even in the control samples (Table 3 ). Even simple pH optimization likely activates indigenous microflora capable of degrading wood polymers. The addition of microorganisms accelerated the degradation of lignin, especially cellulose. The introduction of sawdust to the mixture shifted the polymer degradation toward cellulose. In samples containing sawdust, the loss of cellulose is almost half that of the initial amount. It is logical that under thermostated conditions, the loss of cellulose is more pronounced. In contrast, the loss of lignin in the BWW/sawdust sample was rather small, especially when the sample was incubated at room temperature. Table 3 Content of lignin and cellulose Variant Control BWW BWW/sawdust R*** Т**** R Т R Т Lignin* 33.9 34.4 33.5 32.1 35.0 34.0 Cellulose** 21.3 20.1 19.2 16.8 21.8 18.4 * initial content of lignin in BWW – 37.0, in a mixture of BWW/sawdust – 35.6; ** initial content of cellulose in BWW – 28.0, in a mixture of BWW/sawdust – 32.8; *** R – samples incubated at room temperature; **** T – samples incubated at 37°C in a thermostat According to the calculations, the initial nitrogen and phosphorus contents were 0.13 and 0.18%, respectively (Table 4 ). By the end of the experiment, the amount of phosphorus had decreased by approximately half. This may indicate the transition of soluble phosphorus to its inactive insoluble form or its deposition in the biomass of microorganisms. The degree of nitrogen loss depended on the experimental conditions. For the variants incubated at room temperature, 70% of the losses occurred. In the thermostated samples, losses ranged from 24–32%. Interestingly, this parameter was independent of the presence of microorganisms. Consequently, nitrogen losses are either abiogenic or catalyzed by indigenous microflora. Table 4 Content of labile forms of biogenic elements in substrates Sample Content of biogenic elements, % nitrogen phosphorus Calculated 0.130 0.180 Control R* 0.041 0.064 Control Т** 0.092 0.070 BWW R* 0.041 0.078 BWW Т** 0.096 0.070 BWW/sawdust R* 0.042 0.073 BWW/sawdust Т** 0.096 0.085 * R – samples incubated at room temperature, ** T – samples incubated at 37°C in a thermostat Thus, the best results were observed for the BWW/sawdust variant. This is most likely due to the presence of sawdust in the mixture stimulating the growth and development of the mycelium of wood-destroying fungi in the initial stage. The accumulation of microbial biomass resulted in the acceleration of substrate processing. Next, we carried out a semi-industrial experiment on BWW transformation. A 3:1 mixture of BWW and sawdust was used, which was neutralized with a mixture of nitric and phosphoric acids. The pH of the substrate was measured to be 7.2 immediately after acidification. The substrate was then left for one week under these conditions to allow for uniform neutralization. After two days, the pH decreased to 4.5 and remained at this level for 4 days (Fig. 2 ). Thereafter, the pH gradually shifted toward neutrality. As the pH of the substrate was less than 7 before the introduction of microorganisms, it was decided not to acidify it further but rather to control the pH weekly. The microorganisms were introduced on the 8th day after acidification of the substrate. The pit began to warm up a day after the application of microorganisms and reached a maximum temperature of 56.1°C after 12 days (Fig. 3 ). A smooth decrease in temperature was observed from day 16 of the experiment onward. However, the decrease was not critical, with the temperature of the pit remaining at least 40°С. The pH of the pit stabilized within the neutral range and never exceeded 6.9 (Fig. 4 ). This finding indicates the ability of the introduced microorganisms to stabilize the main monitored process parameters. Samples were collected from different depths at 1, 2 and 3 months of fermentation to determine the degree of toxicity to Chlorella vulgaris (Table 5 ). Table 5 Dynamics of changes in the BWW environmental hazard class in barns at different stages of pre-processing and fermentation Type of sample Hazard class Combined sample of the initial substrate (BWW + sawdust) from the pit 3.8 Combined sample after processing with acids 4 Incremental samples after processing with acids and addition of microorganisms Horizon 10 cm 4 Horizon 50 cm 3,5 Horizon 80 cm 3,5 Incremental samples after 1 month of fermentation Horizon 10 cm 3,5 Horizon 50 cm 4,0 Horizon 80 cm 3,5 Incremental samples after 2 months of fermentation Horizon 10 cm 4,0 Horizon 50 cm 4,5 Horizon 80 cm 4,5 Incremental samples after 3 months of fermentation Horizon 10 cm 5 Horizon 50 cm 5 Horizon 80 cm 5 The table shows that the original hazard class of the substrate was 3.8. Acidification reduced it to the fourth class. However, the substrate becomes more toxic under the action of microorganisms. Only after three months of treatment was the substrate was completely non-toxic (fifth hazard class). A slowdown in the germination of cress seeds was observed at all depths of the pit at all sampling dates by the third day of the experiment (Table 6 ). However, 100% of the seeds subsequently germinated. The average root length and total weight of the seedlings increased with increasing duration of BWW composting, indicating a decrease in substrate toxicity. Consequently, by the end of the processing period, a non-toxic substrate into which seeds could be sown directly was obtained. Table 6 Dynamics of phytotoxicity in the pit at different stages of fermentation Variant Germinated seed, % Root length, cm Germ length, cm Dry weight, g 1 month depth 10 95 3,93 1,24 0,0325 50 95 3,49 1,15 0,026 80 80 3,90 1,23 0,0255 2 months depth 10 95 5,06 1,66 0,038 50 90 4,91 1,22 0,031 80 95 4,81 1,28 0,034 3 months depth 10 95 5,51 0,97 0,041 50 90 6,53 1,05 0,039 80 90 6,08 0,9 0,039 Table 7 shows the main agrochemical characteristics of the target product. For convenience, literature data for high-moor peat (the optimal soil substitute substrate) and gray forest soils (typical of Eastern Siberia) are provided. The determination of agrochemical characteristics enables the properties of soil (soil substitute substrate or fertilizer) to be assessed, revealing how they affect the growth and development of plants. It also reveals the nature and peculiarities of the soil interaction with applied fertilizers and substances originating from the atmosphere. Furthermore, it allows the amount of fertilizers and ameliorants to be calculated for application to the soil. Table 7 Changes in the agrochemical characteristics of BWW during processing Characteristics Initial substrate Final product High-moor peat* Gray forest soil* Cation exchange capacity, mEq/100 g 5.16 8.46 10–12 12–30 Hydrolytic acidity, mEq/100 g 4.82 2.31 5–10 4.6–5.2 Sum of adsorbed bases, mEq/100 g 24.65 40.24 60–90 17–24 Mass content of humic acids in term of dry substance, % 21.3 42.33 9–14 1.9–3.8 Ass content 31.8 31.5 2–12 2.5–15 Mass content of total nitrogen (N) in term of dry substance, % 0.11 0.38 0.7–1.35 0.16–0.27 Content of ammonium nitrogen, mg/100 g 570 740 200 90 Mass content of phosphorus (Р 2 О 5 ) in term of dry substance, % 0.31 0.57 0.1–0.3 0.08–0.2 Mass content of Р 2 О 5 , mg/100 g 134 141 0–15 86–319 рН 5.7 6.9 2–3 4.6–5.2 * literature data (Large information archive 2025 ) One of the main agrochemical characteristics is the reaction of the soil medium: actual acidity, potential acidity and hydrolytic acidity. During BWW processing, the pH was shifted toward the neutral region. This allows the target product to reclaim acidic soils typical of Siberia without the need for additional neutralizing agents. A twofold decrease in hydrolytic acidity was also observed, which indicates the stabilization of the substrate's buffer properties. Another important characteristic is the absorption properties of the soil. These include the cation exchange capacity and the sum of absorbed bases. These parameters reflect the ability of soil or substrate to absorb and provide plants with biogenic elements such as potassium, calcium and magnesium. These parameters increased throughout the experiment. This indicates an improvement in the quality of BWW as a soil. In the target product, these characteristics were only slightly lower than those of peat. The third important parameter is the presence of humic substances, mineral nitrogen and phosphorus, as well as their mobile forms, in the soil or substrate. We have demonstrated that the content of humic acids increases sharply during the composting process. This is most likely due to the active transformation of long-term bark residues by the basidale fungi included in the inoculum. The low content of total nitrogen and phosphorus is because mineral acid solutions are used instead of mineral fertilizers, as is standard practice (Belovezhets 2019 ). However, a steady increase in all these parameters was observed by the end of the experiment. While this amount of nitrogen and phosphorus (in both their total and mobile forms) is insufficient for complete fertilizer, it is quite acceptable for the soil. The high ash content of the product is due to the peculiarities of BWW itself and the use of mineral acids in the acidification process. This indicator does not affect the product properties and enables it to be used as a soil. Conclusion In conclusion, laboratory experiments have demonstrated that long-term stored BWW can undergo microbial degradation. The best results were obtained with the BWW/sawdust mixture. The substrate neutralization conditions were selected to simultaneously lower the pH and introduce the necessary mineral additives for microbial function. A semi-industrial experiment was conducted on a 20 m 3 BWW/sawdust mixture (3:1 ratio). pH stabilization occurred more efficiently than it did in the laboratory experiments. The temperature increase characteristic of the aerobic processing of lignocellulosic waste was also observed. The target product was non-toxic to both plants and Chlorella vulgaris (hazard class 5). Processing improved the agrochemical parameters of the substrate, such as the hydrolytic acidity, cation exchange capacity and sum of absorbed bases. The increase in humic acid content indicates deep microbial degradation of the lignin component of BWW. Consequently, the microbial transformation of BWW was completed, resulting in non-toxic soil. This technology can be scaled up to process large volumes of BWW at storage sites. Declarations Author contributions LA Belovezhets, ideas; formulation of overarching research goals and aims, preparation, creation and presentation of the published work, specifically data visualization, DS Belousov, сonducting a research and investigation process, performing the experiments, data collection, preparation, creation and presentation of the published work, specifically data presentation, NV Filinova, conducting a research and investigation process, specifically performing the experiments, data collection, preparation, creation and presentation of the published work by those from the original research group, specifically critical review, commentary or revision – including pre-or postpublication stages, EO Pristavka, conducting a research and investigation process, specifically performing the experiments, or data/evidence collection, preparation, creation and presentation of the published work, AA Pristavka, conducting a research and investigation process, specifically performing the experiments and data collection Funding The authors declares that no funds, grants, or other support were received during the preparation of this manuscript. Data availability Data will be made available on request. Competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References Belovezhets LA (2019) Method of recycling wood shavings using a wood-destroying microorganisms composition to produce complex organo-mineral fertilizer. Patent RU2701942C1 Belousov DS, Malkov YuA, Belovezhets LA, Samultsev DO (2024) Method for periodic submerged cultivation of basidiomycetes mycelium. Patent RU2821927C1 Dessalegn E, Mathewos M, Gebremeskel H, Tuasha N (2025) Determination of total phenolic and flavonoid contents, antioxidant and antibacterial potential of the bark extracts of Syzygium guineense (Wild.) DC. BMC Complementary Medicine and Therapies 25(1):35. https://doi.org/10.1186/s12906-025-04788-z Hallman LM, Santiago JM, Fox JP, Pitino M, Shatters RG, Rossi L (2023) Use of hardwood mulch applications to improve soil characteristics of Alfisols used in Florida citrus production. Front. Soil Sci. 3:1200847. https://doi.org/10.3389/fsoil.2023.1200847 Hazizah M, Ridwanto R, Daulay AS (2025) Determination of Total Flavonoid Content of Raru Bark Extract: Cotylelobium Melanoxylon Pierre at Various Methanol Concentrations and Antibacterial Activity against Staphylococcus. J. La Medihealtico 6(2):369–382. https://doi.org/10.37899/journallamedihealtico.v6i2.1949 Hossain MM, Ibrahim MN, Parvin MD, Roy MC, Bhuiyan AA, Haque S (2024) Evaluation of Analgesic, antioxidant, and antibacterial activities of methanolic extract of Litsea glutinosa bark from Chuadanga, Bangladesh. J. Phytopharmacology 13(5):407–413. https://doi.org/10.31254/phyto.2024.13510 Interstate standard of the USSR 17.4.4.01-84 (1985) Nature protection. Soils. Methods for determining the capacity of cation exchange. USSR State Committee for Standards, Moscow, 2–6. Interstate standard of the Russian Federation 11306-2013 (2013) Peat and products of its processing. Methods for determination of ash content. Inter-Governmental Council on Standardization, Metrology, and Certification, 2–4. Interstate standard of the USSR 26423–85 (1986) Soils. Methods for determination of specific electric conductivity, рН and solid residue of water extract. USSR State Committee for Standards, Moscow, 3–6. Janah H, Yulianasari DS, Azizah, Fauziyah N, Annisa R, Ahdyani R (2025) Optimization of nano gel formulation based on Bangkal ( Nauclea subdita ) wood bark extract and antibacterial activity against propionibacterium acnes. International J. of Appl. Pharmaceutics 17(3):206–213. https://doi.org/10.22159/ijap.2025v17i3.53657. Kubrina LV, Supinichenko EA (2021) The use of cress as a test object for assessing snow covers pollution. Scientific Review Biological Sciences 1:11–15. https://doi.org/10.17513/srbs.1218 Kulikova Y, Sukhikh S, Babich O, Yuliya M, Krasnovskikh M, Noskova S (2022) Feasibility of Old Bark and Wood Waste Recycling. Plants 11(12):1549. https://doi.org/10.3390/plants11121549. Large information archive (2025) Agrochemical properties of peat https://big-archive.ru/biology/the_peat_bogs_of_Russian_forest-steppe/31.php Accessed 22 July 2025 Margina Y, Troegubov A, Kulikova Y, Sliusar N (2023) Composting Old Bark and Wood Waste in Cold Weather Conditions. Sustainability 15(14):10768. https://doi.org/10.3390/su151410768 Martynov VV, Shchemelinina TN, Anchugova EM (2024) Potential of utilizing aged bark-and-wood waste through mycological degradation as a biotechnological process. Povolzhskiy Journal of Ecology 4:500–508. https://doi.org/10.35885/1684-7318-2024-4-500-508 National standard of the Russian Federation 54496-2011. ISO 8692:2004 (2011) Water. Determination of toxicity with use of green freshwater unicellular algae. Standartinform, Moscow, 1–53. Petrunina EA, Loskutov SR, Ryazanova TV, Aniskina AA, Permyakova GV, Stasova VV (2022) Comparative analysis of physical-chemical properties of larch and pine bark: thermal analysis and analytical pyrolysis. Sib. J. For. Sci. 4:35–49. https://doi.org/10.15372/SJFS20220405 State standard of the USSR 9517-76 (1977) Brown coals and hard coals. Methods for determination of humic acids yield. USSR State Committee for Standards, Moscow, 1–5. State standard of the USSR 26212-91 (1993) Soils. Determination of hydrolytic acidity by Kappen method modified by CINAO. USSR Committee for Standardization and Metrology, Moscow, 1–5. State standard of the USSR 27821-88 (1990) Soils. Determination of base absorption sum by Kappen method. USSR State Committee for Standards, Moscow, 1–4. State standard of the USSR 27894.3–88 (1988) Peat and products of its processing for agriculture. Methods for determination of ammonia nitrogen. USSR State Committee for Standards, Moscow, 2–9. State standard of the USSR 27894.5-88 (1988) Peat and products of its processing for agriculture. Methods for determination of mobile forms of phosphorus. USSR State Committee for Standards, Moscow, 1–7. The state and protection of the environment of the Russian Federation in 2022: state report (2023) Ministry of Natural Resources of Russia: Lomonosov Moscow State University, pp 185-186. Yue F, Zhang J, Xu J, Niu T, Lü X, Liu M (2022) Effects of monosaccharide composition on quantitative analysis of total sugar content by phenol-sulfuric acid method. Front. Nutr . 9:963318. https://doi.org/10.3389/fnut.2022.963318 Cite Share Download PDF Status: Published Journal Publication published 10 Apr, 2026 Read the published version in Biotechnology Letters → Version 1 posted Reviewers agreed at journal 06 Dec, 2025 Reviewers invited by journal 02 Oct, 2025 Editor assigned by journal 19 Sep, 2025 First submitted to journal 18 Sep, 2025 Editorial decision: Major revisions 16 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7628066","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":523947858,"identity":"03a2b514-9c04-4463-8fd9-61fa303fdbd1","order_by":0,"name":"Ludmila Alexandrovna Belovezhets","email":"","orcid":"","institution":"AE Favorsky Irkutsk Institute of Chemistry SB RAS: Irkutskij institut himii imeni A E Favorskogo SO RAN","correspondingAuthor":false,"prefix":"","firstName":"Ludmila","middleName":"Alexandrovna","lastName":"Belovezhets","suffix":""},{"id":523947859,"identity":"e4766dfd-4e20-45d2-a894-f95c460ad1f8","order_by":1,"name":"Dmitry Sergeevich Belousov","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIie3QMQrCMBSA4RcCyZLqKlQ8gyJYC2rPUgQnxQM4mBLIVHdFvEZmJYNX6KYiODm4Ch2Moo5p3RzyL3nD+yAJgMv1hzUB8/eIjrcbAKsUE/QhuLVaGkJ+ImtmjkIS0CQ5s7wXcyqQ6I8HdQLepWYjYboTbU+OYs40EhM1NBejHStpZrH0Pa7bUJvuzxOFDSHETg4n6bP8SYZIhGpegmTIEKIbL4KULiZhGovWRo4aYN6SLNSeEUxw10YCqnfHa95jYH6M39UsqlKJMhv5Fm0/Ey6173K5XC5bDzP1O5D67PehAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-1412-9572","institution":"AE Favorsky Irkutsk Institute of Chemistry SB RAS: Irkutskij institut himii imeni A E Favorskogo SO RAN","correspondingAuthor":true,"prefix":"","firstName":"Dmitry","middleName":"Sergeevich","lastName":"Belousov","suffix":""},{"id":523947860,"identity":"7ecb8483-fabe-454e-bc6e-f919b54a74de","order_by":2,"name":"Nadezhda Vladimirovna Filinova","email":"","orcid":"","institution":"AE Favorsky Irkutsk Institute of Chemistry SB RAS: Irkutskij institut himii imeni A E Favorskogo SO RAN","correspondingAuthor":false,"prefix":"","firstName":"Nadezhda","middleName":"Vladimirovna","lastName":"Filinova","suffix":""},{"id":523947861,"identity":"141680f4-f42e-4dec-98c8-ea659bc1e68d","order_by":3,"name":"Ekaterina Olegovna Pristavka","email":"","orcid":"","institution":"AE Favorsky Irkutsk Institute of Chemistry SB RAS: Irkutskij institut himii imeni A E Favorskogo SO RAN","correspondingAuthor":false,"prefix":"","firstName":"Ekaterina","middleName":"Olegovna","lastName":"Pristavka","suffix":""},{"id":523947862,"identity":"08acbaa6-61eb-4374-99d9-f3037e4778b1","order_by":4,"name":"Aleksey Alexandrovich Pristavka","email":"","orcid":"","institution":"Irkutsk State University: Irkutskij gosudarstvennyj universitet","correspondingAuthor":false,"prefix":"","firstName":"Aleksey","middleName":"Alexandrovich","lastName":"Pristavka","suffix":""}],"badges":[],"createdAt":"2025-09-16 08:48:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7628066/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7628066/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10529-026-03730-8","type":"published","date":"2026-04-10T15:58:20+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":93614637,"identity":"09a0ec8c-9c9e-4794-9419-1e3edef1fb63","added_by":"auto","created_at":"2025-10-15 16:40:03","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":9730,"visible":true,"origin":"","legend":"","description":"","filename":"bileBILED2500531.xml","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/202fb33134a4e25e08f59249.xml"},{"id":93614638,"identity":"8bd4a82b-9377-4bae-95c8-c71397732a00","added_by":"auto","created_at":"2025-10-15 16:40:03","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":997,"visible":true,"origin":"","legend":"","description":"","filename":"BILED250053120332.go.xml","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/28a6aacad08ed0a15cc73c46.xml"},{"id":93615523,"identity":"00b630c7-8ad3-47b6-87bf-c5cbe9da4820","added_by":"auto","created_at":"2025-10-15 16:48:03","extension":"xml","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":884,"visible":true,"origin":"","legend":"","description":"","filename":"BILED2500531Import.xml","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/e0408b7620c10327728c3348.xml"},{"id":93615524,"identity":"19650dad-5927-4703-86b3-8d8fc4bc45bf","added_by":"auto","created_at":"2025-10-15 16:48:03","extension":"xml","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":90586,"visible":true,"origin":"","legend":"","description":"","filename":"BILED25005311enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/9a1b491f6291700393e52c2e.xml"},{"id":93614641,"identity":"7c9424f2-1d22-4316-8e0a-cefe91c46f2e","added_by":"auto","created_at":"2025-10-15 16:40:03","extension":"eps","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":187463,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage2.eps","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/377abf998b86365b1626f275.eps"},{"id":93614642,"identity":"d3cc29f6-690e-4f0c-a160-e2e857917c13","added_by":"auto","created_at":"2025-10-15 16:40:03","extension":"xml","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":89455,"visible":true,"origin":"","legend":"","description":"","filename":"BILED25005311structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/c0f1c32a17c94ded87f68668.xml"},{"id":93616262,"identity":"bf402b99-10f2-4aa6-9d5c-bf2981235335","added_by":"auto","created_at":"2025-10-15 16:56:03","extension":"html","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":95326,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/903833aa63bee7a845f913f6.html"},{"id":93614634,"identity":"31d9a020-a5bb-48f1-8f79-7c91f4de0b98","added_by":"auto","created_at":"2025-10-15 16:40:03","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":95882,"visible":true,"origin":"","legend":"\u003cp\u003eрН dynamics for different options of the experiment. \u003cstrong\u003eА\u003c/strong\u003e BWW + association of microorganisms. \u003cstrong\u003eВ\u003c/strong\u003e BWW/sawdust + association of microorganisms. * R – samples incubated at room temperature, ** T – samples incubated at 37°C in a thermostat\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/73e859a79f80b625c55afba3.jpg"},{"id":93615522,"identity":"ee7aa488-bb6d-4d56-876c-024eb8fc3184","added_by":"auto","created_at":"2025-10-15 16:48:03","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":19746,"visible":true,"origin":"","legend":"\u003cp\u003epH dynamics prior to the addition of microorganisms\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/1adc2c9cd8e65cd561d00907.jpg"},{"id":93614635,"identity":"4e7038d4-5d28-4366-bb87-c5093ab27b18","added_by":"auto","created_at":"2025-10-15 16:40:03","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":30142,"visible":true,"origin":"","legend":"\u003cp\u003eDynamics of the average temperature in the pit\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/7982c2641cad3b7c33da5a91.jpg"},{"id":93614640,"identity":"ffa99da7-ced1-44b9-97b3-0ef63649a958","added_by":"auto","created_at":"2025-10-15 16:40:03","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":24340,"visible":true,"origin":"","legend":"\u003cp\u003eрН dynamics in the pit\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/62a194205f37040f83b084c7.jpg"},{"id":106810979,"identity":"ec8a80de-37ce-43a1-b889-522237ee360a","added_by":"auto","created_at":"2026-04-13 16:17:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":887137,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7628066/v1/08428214-4c69-4067-849a-13891f50aa09.pdf"}],"financialInterests":"","formattedTitle":"Application of wood sawdust microbial transformation for the utilization of long-term stored bark-wood waste","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe volume of wood harvested worldwide is large (3.91\u0026nbsp;billion m\u003csup\u003e3\u003c/sup\u003e in 2022) and is increasing annually by an average of 0.8% (State report 2023). Owing to the long-term activity of large wood processing enterprises, environmental pollution has become a biosphere-wide process. In Russia, no more than half of the biomass of harvested wood is used sustainably. Consequently, wood processing enterprises generate approximately 68\u0026ndash;74\u0026nbsp;million m\u003csup\u003e3\u003c/sup\u003e of wood waste annually, of which only 48\u0026ndash;58% is processed. One of the main types of sawmill waste is bark, which accounts for 8\u0026ndash;15% of the waste structure. Due to its complex chemical and mechanical structure, bark is not widely used in secondary processing (Petrunina et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The only industrial application of conifer bark is in the landscape, agrotechnical and design works to mulch the soil and improve the aesthetic appearance of parks (Hallman et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). The microbial decomposition of bark is a slow process due to its high antibacterial and disinfectant contents (Janah et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Dessalegn et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Hazizah et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Hossain et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Bark-wood waste (BWW) accumulates in large quantities in pulp and paper mill dumps (Kulikova et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). This waste is almost not involved in further utilization. This leads to the formation of environmental disaster zones in the areas surrounding pulp and paper mills due to the toxic effects of BWW components on soil and groundwater. The inconsistent composition and the presence of hard-to-degrade polymers in BWW make it extremely unfavorable substrate for chemical and thermal utilization. Moreover, long-term stored BWW can undergo microbial processing to produce fungal enzymes (Martynov et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) and even composting (Margina et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). A method for the microbial processing of sawmill waste into organic-mineral fertilizer was developed at the Irkutsk Institute of Chemistry (Belovezhets \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). This work aimed to investigate the potential application of this technology to process bark-wood waste into environmentally safe soil.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003eLong-term stored BWW from Bratsk Pulp and Paper Mill (elemental composition: C 18.01, H 2.29, P 0.45, N 0.0, S 0.0, ash 45.51, lignin 37.0, cellulose 28.0, pH 9.4) and fresh softwood sawdust (elemental composition: C 17.84, H 6.17, P 0.3, N 0.03, S 0.61, ash 3.68, lignin 31.3, cellulose 47.3, pH 4.5) were used as substrates. Elemental analysis was performed automatically on a Flash EA 1112 CHN-O/MAS 200 microanalyzer. The moisture content was determined on a moisture meter AND MX-50 (Japan), and the pH was determined on a pH-meter Expert-pH (\u0026ldquo;Econix\u0026rdquo; Russia) according to GOST 26423-85 (Interstate standard of the USSR, 1986). The substrates were neutralized with 0.8% NH\u003csub\u003e4\u003c/sub\u003eNO\u003csub\u003e3\u003c/sub\u003e or a mixture of 4% HNO\u003csub\u003e3\u003c/sub\u003e and H\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003eFor the laboratory experiments, the following compositions were used:\u003c/p\u003e\n\u003cp\u003e1. BWW\u0026thinsp;+\u0026thinsp;association of microorganisms\u003c/p\u003e\n\u003cp\u003e2. BWW\u0026thinsp;+\u0026thinsp;association of microorganisms\u0026thinsp;+\u0026thinsp;sawdust\u003c/p\u003e\n\u003cp\u003eNeutralized BWW without microorganisms served as the control.\u003c/p\u003e\n\u003cp\u003eIn all the cases, 4 liters of substrate, pre-neutralized and humidified to the optimum moisture content, were employed. The ratio of BWW/sawdust was 3:1.\u003c/p\u003e\n\u003cp\u003eMicroorganism cultures of \u003cem\u003ePaecilomyces variotii sp\u003c/em\u003e., \u003cem\u003ePhanerochaete chrysosporium, Trametes versicolor, Sporotrichum pulverulentum\u003c/em\u003e (14B), and \u003cem\u003eSporotrichum pulverulentum\u003c/em\u003e (14G), which were isolated from infected wood in Eastern Siberia and identified on the basis of 26S-RNA in the All-Russian Collection of Industrial Microorganisms, were used in this study. One hour after acidification, a mixture of five-day-old fungal cultures grown individually (on modified Sabouraud\u0026apos;s nutrient medium, under stationary conditions at 26\u0026deg;C) was added to the substrates. As neutralization was carried out using a mixture of nitric and phosphoric acids, mineral additives were not employed (Belovezhets 2019). Dilute acid solutions were prepared from the culture filtrate. The substrates were neutralized to a pH of 5.6\u0026ndash;6.2. Modeling of real exothermic composting processes, which is impossible with a small substrate volume, was performed by incubation of the mixture in a thermostat at 37\u0026deg;C. The moisture content was maintained at 60\u0026ndash;70%. The duration of the experiment was 5 months. Lignin loss was estimated gravimetrically after hydrolysis with 72% Н\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e, and cellulose loss was evaluated indirectly by determining the amount of reducing substances in terms of glucose content via the phenol-sulfuric acid method (Yue et al. 2022). The mobile forms of nitrogen were determined according to GOST 27894.3\u0026ndash;88 (State standard of the USSR 1988), phosphorus was determined according to GOST 27894.5\u0026ndash;88 (State standard of the USSR 1988), and the cation exchange capacity (mEq/100 g) was determined according to GOST 17.4.4. 01\u0026ndash;84 (Interstate standard of the USSR 1985), hydrolytic acidity (mEq/100 g) according to GOST 26212-91 (State standard of the USSR 1993), the sum of absorbed bases (mEq/100 g) according to GOST 27821-88 (State standard of the USSR 1990), the mass fraction of humic acids in terms of dry matter (%) according to GOST 9517-76 (State standard of the USSR 1977), and ash content according to GOST 11306\u0026thinsp;\u0026minus;\u0026thinsp;2013 (Interstate standard of the Russian Federation 2013). The phytotoxicity of the samples was established using the biotesting method on higher plant cress (\u003cem\u003eLepidium sativum\u003c/em\u003e) (Kubrina and Supinichenko 2021), and the toxicity of the aqueous extracts was determined via the use of green freshwater unicellular algae (\u003cem\u003eChlorella vulgaris beijer\u003c/em\u003e) according to GOST R 54496\u0026thinsp;\u0026minus;\u0026thinsp;2011 (National standard of the Russian Federation 2011).\u003c/p\u003e\n\u003cp\u003eThe semi-industrial experiment was carried out with the following substrates: BWW, 15 m\u003csup\u003e3\u003c/sup\u003e; sawdust 5, m\u003csup\u003e3\u003c/sup\u003e (pH of the mixture was 8.5). The experiment was performed on 26.05.2024 at the site belonging to the A.E. Favorsky Irkutsk Institute of Chemistry of the Siberian Branch of the Russian Academy of Sciences, Russia, Irkutsk (geographic coordinates: 52\u0026deg;24\u0026apos; N 104\u0026deg;26\u0026apos; E). The site was preliminarily cleared from vegetation and leveled. The substrate was spread in an even 0.5 m-thick layer and subjected to neutralization with a 3:1 mixture of nitric and phosphoric acids. For neutralization, the acid was diluted with tap water to a concentration of 4%. The substrate was watered using a submersible pump (Vikhr VN-10N, Russia). Neutralization was carried out once. Microorganisms were grown individually (Belousov et al. 2024).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe starting BWWs are highly toxic (hazard class 3.5), which makes them unsuitable for use as soil. This problem can be solved using the directed microbial transformation. It was hypothesized that the association of non-pathogenic basidial fungi employed for processing wood sawdust could also be effective for BWW utilization. To optimize the conditions for these fungi, one version of the laboratory experiment included a mixture of sawdust and BWW.\u003c/p\u003e\u003cp\u003ePreliminary experiments revealed that BWW and sawdust have highly imbalanced elemental compositions. They are also characterized by high ash content and high pH values (BWW: 9.4; BWW/sawdust mixture: 8.5). Consequently, it was necessary to select an adequate neutralization option in the first stage of the laboratory experiment. As the optimum pH for fungal performance is 5.5\u0026ndash;6.9, it was set to between 6.0 and 6.8 before the cultures were applied. Initially, 0.8% NH\u003csub\u003e4\u003c/sub\u003eNO\u003csub\u003e3\u003c/sub\u003e was used for neutralization. However, even when 25.7% of the total substrate volume was applied, the ammonium nitrate solution did not reduce the pH to the required level. Therefore, neutralization with a mixture of 4% HNO\u003csub\u003e3\u003c/sub\u003e and 4% H\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e was performed. The results of the pH dynamics are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eNeutralization of BWW with 0.8% NH\u003csub\u003e4\u003c/sub\u003eNO\u003csub\u003e3\u003c/sub\u003e and a mixture of 4% HNO\u003csub\u003e3\u003c/sub\u003e and 4% H\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eContent of NH\u003csub\u003e4\u003c/sub\u003eNO\u003csub\u003e3\u003c/sub\u003e, % vol.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eрН\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eContent of HNO\u003csub\u003e3\u003c/sub\u003e and H\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e, % vol.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eрН\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e0.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e9.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e9.4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e6.9\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e6.6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e8.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.70\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e6.6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e6.6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e15.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e6.6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e19.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e6.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e25.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTwo days after the start of the experiment, the pH was 6.1 for the experimental samples and 7.1 for the control samples. However, owing to the high buffer capacity of the substrates, the pH began to shift toward the alkaline region one week after neutralization. To increase the pH above 7.2, the substrates used in the laboratory experiments were additionally acidified with a mixture of 0.5% HNO\u003csub\u003e3\u003c/sub\u003e and 0.5% H\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e during watering. This low concentration was used to reduce the risk of adverse effects on microbial associations. Unfortunately, the pH of all the samples tended to increase. In the control samples, alkalinization of the medium occurred much faster reaching higher values. Watering with diluted acids was carried out twice a week. In all the experiments, the pH stabilized after two months (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Therefore, further acidification of the experimental samples was not carried out. During the third and fourth months of the experiment, the pH remained stable. In the room temperature experiments, the pH reached relatively high values during the first stage but stabilized at the level of the thermostated variants during the last month. This is most likely due to microorganisms being more active at elevated temperatures. Interestingly, the second wave of substrate alkalinization began in the fourth month of the experiment. Even in the experimental samples, the pH reached 8.1 (8.4 in the control) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Moreover, the pH was higher in the thermostated samples than in the samples incubated at room temperature.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eNotably, the samples cultivated at elevated temperatures presented abundant fungal growth and a pronounced fungal odor, as observed visually one week after the start of the experiment. Similar results for samples grown at room temperature were noted only after two months.\u003c/p\u003e\u003cp\u003eThe toxicity class determined using \u003cem\u003eChlorella vulgaris\u003c/em\u003e (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) increased in the thermostated samples in the middle of the experiment and decreased to the fifth class by the end of the third month. Moreover, the toxicity of the samples incubated at room temperature increased over time. These findings suggest that the observed effects are most likely attributable to delayed processing of compounds that are toxic to \u003cem\u003eChlorella vulgaris\u003c/em\u003e at room temperature. However, the toxicity level increased again by the fifth month of the experiment. This was attributed to an increase in substrate pH (according to preliminary experiments, alkalinization of the solution negatively affects the growth of \u003cem\u003eChlorella vulgaris\u003c/em\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eToxicity class determined using \u003cem\u003eСhlorella vulgaris\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariant\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eBWW\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003eBWW/sawdust\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIncubation time\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eR*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eT**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eT\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eT\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e4.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e* R \u0026ndash; samples incubated at room temperature, ** T \u0026ndash; samples incubated at 37\u0026deg;C in a thermostat\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eLoss of lignin and cellulose was observed even in the control samples (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Even simple pH optimization likely activates indigenous microflora capable of degrading wood polymers. The addition of microorganisms accelerated the degradation of lignin, especially cellulose. The introduction of sawdust to the mixture shifted the polymer degradation toward cellulose. In samples containing sawdust, the loss of cellulose is almost half that of the initial amount. It is logical that under thermostated conditions, the loss of cellulose is more pronounced. In contrast, the loss of lignin in the BWW/sawdust sample was rather small, especially when the sample was incubated at room temperature.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eContent of lignin and cellulose\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eVariant\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eBWW\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003eBWW/sawdust\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eR***\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eТ****\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eТ\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eТ\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLignin*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e33.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e34.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e33.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e32.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e35.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e34.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCellulose**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e21.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e20.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e19.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e16.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e21.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e18.4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e* initial content of lignin in BWW \u0026ndash; 37.0, in a mixture of BWW/sawdust \u0026ndash; 35.6; ** initial content of cellulose in BWW \u0026ndash; 28.0, in a mixture of BWW/sawdust \u0026ndash; 32.8; *** R \u0026ndash; samples incubated at room temperature; **** T \u0026ndash; samples incubated at 37\u0026deg;C in a thermostat\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAccording to the calculations, the initial nitrogen and phosphorus contents were 0.13 and 0.18%, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). By the end of the experiment, the amount of phosphorus had decreased by approximately half. This may indicate the transition of soluble phosphorus to its inactive insoluble form or its deposition in the biomass of microorganisms. The degree of nitrogen loss depended on the experimental conditions. For the variants incubated at room temperature, 70% of the losses occurred. In the thermostated samples, losses ranged from 24\u0026ndash;32%. Interestingly, this parameter was independent of the presence of microorganisms. Consequently, nitrogen losses are either abiogenic or catalyzed by indigenous microflora.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eContent of labile forms of biogenic elements in substrates\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eSample\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eContent of biogenic elements, %\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003enitrogen\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ephosphorus\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCalculated\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.130\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.180\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eControl R*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.041\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.064\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eControl Т**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.092\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.070\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBWW R*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.041\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.078\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBWW Т**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.096\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.070\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBWW/sawdust R*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.042\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.073\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBWW/sawdust Т**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.096\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.085\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"3\"\u003e* R \u0026ndash; samples incubated at room temperature, ** T \u0026ndash; samples incubated at 37\u0026deg;C in a thermostat\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThus, the best results were observed for the BWW/sawdust variant. This is most likely due to the presence of sawdust in the mixture stimulating the growth and development of the mycelium of wood-destroying fungi in the initial stage. The accumulation of microbial biomass resulted in the acceleration of substrate processing.\u003c/p\u003e\u003cp\u003eNext, we carried out a semi-industrial experiment on BWW transformation. A 3:1 mixture of BWW and sawdust was used, which was neutralized with a mixture of nitric and phosphoric acids. The pH of the substrate was measured to be 7.2 immediately after acidification. The substrate was then left for one week under these conditions to allow for uniform neutralization. After two days, the pH decreased to 4.5 and remained at this level for 4 days (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Thereafter, the pH gradually shifted toward neutrality. As the pH of the substrate was less than 7 before the introduction of microorganisms, it was decided not to acidify it further but rather to control the pH weekly. The microorganisms were introduced on the 8th day after acidification of the substrate.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe pit began to warm up a day after the application of microorganisms and reached a maximum temperature of 56.1\u0026deg;C after 12 days (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). A smooth decrease in temperature was observed from day 16 of the experiment onward. However, the decrease was not critical, with the temperature of the pit remaining at least 40\u0026deg;С.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe pH of the pit stabilized within the neutral range and never exceeded 6.9 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). This finding indicates the ability of the introduced microorganisms to stabilize the main monitored process parameters.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eSamples were collected from different depths at 1, 2 and 3 months of fermentation to determine the degree of toxicity to \u003cem\u003eChlorella vulgaris\u003c/em\u003e (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDynamics of changes in the BWW environmental hazard class in barns at different stages of pre-processing and fermentation\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eType of sample\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHazard class\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCombined sample of the initial substrate (BWW\u0026thinsp;+\u0026thinsp;sawdust) from the pit\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.8\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCombined sample after processing with acids\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIncremental samples after processing with acids and addition of microorganisms\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 10 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 50 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3,5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 80 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3,5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIncremental samples after 1 month of fermentation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 10 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3,5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 50 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4,0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 80 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3,5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIncremental samples after 2 months of fermentation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 10 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4,0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 50 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4,5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 80 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4,5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIncremental samples after 3 months of fermentation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 10 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 50 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHorizon 80 cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe table shows that the original hazard class of the substrate was 3.8. Acidification reduced it to the fourth class. However, the substrate becomes more toxic under the action of microorganisms. Only after three months of treatment was the substrate was completely non-toxic (fifth hazard class).\u003c/p\u003e\u003cp\u003eA slowdown in the germination of cress seeds was observed at all depths of the pit at all sampling dates by the third day of the experiment (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). However, 100% of the seeds subsequently germinated. The average root length and total weight of the seedlings increased with increasing duration of BWW composting, indicating a decrease in substrate toxicity. Consequently, by the end of the processing period, a non-toxic substrate into which seeds could be sown directly was obtained.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDynamics of phytotoxicity in the pit at different stages of fermentation\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e\u003cp\u003eVariant\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGerminated seed, %\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRoot length, cm\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eGerm length, cm\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eDry weight, g\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c6\" namest=\"c3\"\u003e\u003cp\u003e1 month\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003edepth\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,0325\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,026\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,0255\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c6\" namest=\"c3\"\u003e\u003cp\u003e2 months\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003edepth\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5,06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,038\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,91\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,031\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,034\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c6\" namest=\"c3\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003edepth\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5,51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0,97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,041\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6,53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,039\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6,08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0,9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0,039\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e shows the main agrochemical characteristics of the target product. For convenience, literature data for high-moor peat (the optimal soil substitute substrate) and gray forest soils (typical of Eastern Siberia) are provided.\u003c/p\u003e\u003cp\u003eThe determination of agrochemical characteristics enables the properties of soil (soil substitute substrate or fertilizer) to be assessed, revealing how they affect the growth and development of plants. It also reveals the nature and peculiarities of the soil interaction with applied fertilizers and substances originating from the atmosphere. Furthermore, it allows the amount of fertilizers and ameliorants to be calculated for application to the soil.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eChanges in the agrochemical characteristics of BWW during processing\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eInitial substrate\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eFinal product\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHigh-moor peat*\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eGray forest soil*\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCation exchange capacity, mEq/100 g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10\u0026ndash;12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e12\u0026ndash;30\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydrolytic acidity, mEq/100 g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5\u0026ndash;10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4.6\u0026ndash;5.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSum of adsorbed bases, mEq/100 g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e24.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e40.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e60\u0026ndash;90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e17\u0026ndash;24\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMass content of humic acids in term of dry substance, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e21.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e42.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e9\u0026ndash;14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.9\u0026ndash;3.8\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAss content\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e31.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2\u0026ndash;12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.5\u0026ndash;15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMass content of total nitrogen (N) in term of dry substance, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.7\u0026ndash;1.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.16\u0026ndash;0.27\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eContent of ammonium nitrogen, mg/100 g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e570\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e740\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e200\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e90\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMass content of phosphorus (Р\u003csub\u003e2\u003c/sub\u003eО\u003csub\u003e5\u003c/sub\u003e) in term of dry substance, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.1\u0026ndash;0.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.08\u0026ndash;0.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMass content of Р\u003csub\u003e2\u003c/sub\u003eО\u003csub\u003e5\u003c/sub\u003e, mg/100 g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e134\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e141\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0\u0026ndash;15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e86\u0026ndash;319\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eрН\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2\u0026ndash;3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4.6\u0026ndash;5.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e* literature data (Large information archive \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2025\u003c/span\u003e)\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eOne of the main agrochemical characteristics is the reaction of the soil medium: actual acidity, potential acidity and hydrolytic acidity. During BWW processing, the pH was shifted toward the neutral region. This allows the target product to reclaim acidic soils typical of Siberia without the need for additional neutralizing agents. A twofold decrease in hydrolytic acidity was also observed, which indicates the stabilization of the substrate's buffer properties.\u003c/p\u003e\u003cp\u003eAnother important characteristic is the absorption properties of the soil. These include the cation exchange capacity and the sum of absorbed bases. These parameters reflect the ability of soil or substrate to absorb and provide plants with biogenic elements such as potassium, calcium and magnesium. These parameters increased throughout the experiment. This indicates an improvement in the quality of BWW as a soil. In the target product, these characteristics were only slightly lower than those of peat.\u003c/p\u003e\u003cp\u003eThe third important parameter is the presence of humic substances, mineral nitrogen and phosphorus, as well as their mobile forms, in the soil or substrate. We have demonstrated that the content of humic acids increases sharply during the composting process. This is most likely due to the active transformation of long-term bark residues by the basidale fungi included in the inoculum. The low content of total nitrogen and phosphorus is because mineral acid solutions are used instead of mineral fertilizers, as is standard practice (Belovezhets \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). However, a steady increase in all these parameters was observed by the end of the experiment. While this amount of nitrogen and phosphorus (in both their total and mobile forms) is insufficient for complete fertilizer, it is quite acceptable for the soil.\u003c/p\u003e\u003cp\u003eThe high ash content of the product is due to the peculiarities of BWW itself and the use of mineral acids in the acidification process. This indicator does not affect the product properties and enables it to be used as a soil.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, laboratory experiments have demonstrated that long-term stored BWW can undergo microbial degradation. The best results were obtained with the BWW/sawdust mixture. The substrate neutralization conditions were selected to simultaneously lower the pH and introduce the necessary mineral additives for microbial function. A semi-industrial experiment was conducted on a 20 m\u003csup\u003e3\u003c/sup\u003e BWW/sawdust mixture (3:1 ratio). pH stabilization occurred more efficiently than it did in the laboratory experiments. The temperature increase characteristic of the aerobic processing of lignocellulosic waste was also observed. The target product was non-toxic to both plants and \u003cem\u003eChlorella vulgaris\u003c/em\u003e (hazard class 5). Processing improved the agrochemical parameters of the substrate, such as the hydrolytic acidity, cation exchange capacity and sum of absorbed bases. The increase in humic acid content indicates deep microbial degradation of the lignin component of BWW. Consequently, the microbial transformation of BWW was completed, resulting in non-toxic soil. This technology can be scaled up to process large volumes of BWW at storage sites.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e LA Belovezhets, ideas; formulation of overarching research goals and aims, preparation, creation and presentation of the published work, specifically data visualization, DS Belousov, сonducting a research and investigation process, performing the experiments, data collection, preparation, creation and presentation of the published work, specifically data presentation, NV Filinova, conducting a research and investigation process, specifically performing the experiments, \u0026nbsp;data collection, preparation, creation and presentation of the published work by those from the original research group, specifically critical review, commentary or revision \u0026ndash; including pre-or postpublication stages, EO Pristavka, conducting a research and investigation process, specifically performing the experiments, or data/evidence collection, preparation, creation and presentation of the published work, AA Pristavka, conducting a research and investigation process, specifically performing the experiments and data collection\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e The authors declares that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003eData will be made available on request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBelovezhets LA (2019) Method of recycling wood shavings using a wood-destroying microorganisms composition to produce complex organo-mineral fertilizer. Patent RU2701942C1\u003c/li\u003e\n\u003cli\u003eBelousov DS, Malkov YuA, Belovezhets LA, Samultsev DO (2024) Method for periodic submerged cultivation of basidiomycetes mycelium. Patent RU2821927C1\u003c/li\u003e\n\u003cli\u003eDessalegn E, Mathewos M, Gebremeskel H, Tuasha N (2025) Determination of total phenolic and flavonoid contents, antioxidant and antibacterial potential of the bark extracts of \u003cem\u003eSyzygium guineense\u003c/em\u003e (Wild.) DC. BMC Complementary Medicine and Therapies 25(1):35. https://doi.org/10.1186/s12906-025-04788-z\u003c/li\u003e\n\u003cli\u003eHallman LM, Santiago JM, Fox JP, Pitino M, Shatters RG, Rossi L (2023) Use of hardwood mulch applications to improve soil characteristics of Alfisols used in Florida citrus production. Front. Soil Sci. 3:1200847. https://doi.org/10.3389/fsoil.2023.1200847\u003c/li\u003e\n\u003cli\u003eHazizah M, Ridwanto R, Daulay AS (2025) Determination of Total Flavonoid Content of Raru Bark Extract: Cotylelobium Melanoxylon Pierre at Various Methanol Concentrations and Antibacterial Activity against Staphylococcus. J. La Medihealtico 6(2):369\u0026ndash;382. https://doi.org/10.37899/journallamedihealtico.v6i2.1949\u003c/li\u003e\n\u003cli\u003eHossain MM, Ibrahim MN, Parvin MD, Roy MC, Bhuiyan AA, Haque S (2024) Evaluation of Analgesic, antioxidant, and antibacterial activities of methanolic extract of Litsea glutinosa bark from Chuadanga, Bangladesh. J. Phytopharmacology 13(5):407\u0026ndash;413. https://doi.org/10.31254/phyto.2024.13510\u003c/li\u003e\n\u003cli\u003eInterstate standard of the USSR 17.4.4.01-84 (1985) Nature protection. Soils. Methods for determining the capacity of cation exchange. USSR State Committee for Standards, Moscow, 2\u0026ndash;6.\u003c/li\u003e\n\u003cli\u003eInterstate standard of the Russian Federation 11306-2013 (2013) Peat and products of its processing. Methods for determination of ash content. Inter-Governmental Council on Standardization, Metrology, and Certification, 2\u0026ndash;4.\u003c/li\u003e\n\u003cli\u003eInterstate standard of the USSR 26423\u0026ndash;85 (1986) Soils. Methods for determination of specific electric conductivity, рН and solid residue of water extract. USSR State Committee for Standards, Moscow, 3\u0026ndash;6.\u003c/li\u003e\n\u003cli\u003eJanah H, Yulianasari DS, Azizah, Fauziyah N, Annisa R, Ahdyani R (2025) Optimization of nano gel formulation based on Bangkal (\u003cem\u003eNauclea subdita\u003c/em\u003e) wood bark extract and antibacterial activity against propionibacterium acnes. International J. of Appl. Pharmaceutics 17(3):206\u0026ndash;213. https://doi.org/10.22159/ijap.2025v17i3.53657.\u003c/li\u003e\n\u003cli\u003eKubrina LV, Supinichenko EA (2021) The use of cress as a test object for assessing snow covers pollution. Scientific Review Biological Sciences 1:11\u0026ndash;15. https://doi.org/10.17513/srbs.1218\u003c/li\u003e\n\u003cli\u003eKulikova Y, Sukhikh S, Babich O, Yuliya M, Krasnovskikh M, Noskova S (2022) Feasibility of Old Bark and Wood Waste Recycling. Plants 11(12):1549. https://doi.org/10.3390/plants11121549.\u003c/li\u003e\n\u003cli\u003eLarge information archive (2025) Agrochemical properties of peat \u003cu\u003ehttps://big-archive.ru/biology/the_peat_bogs_of_Russian_forest-steppe/31.php\u003c/u\u003e Accessed 22 July 2025\u003c/li\u003e\n\u003cli\u003eMargina Y, Troegubov A, Kulikova Y, Sliusar N (2023) Composting Old Bark and Wood Waste in Cold Weather Conditions. Sustainability 15(14):10768. https://doi.org/10.3390/su151410768\u003c/li\u003e\n\u003cli\u003eMartynov VV, Shchemelinina TN, Anchugova EM (2024) Potential of utilizing aged bark-and-wood waste through mycological degradation as a biotechnological process. Povolzhskiy Journal of Ecology 4:500\u0026ndash;508. https://doi.org/10.35885/1684-7318-2024-4-500-508\u003c/li\u003e\n\u003cli\u003eNational standard of the Russian Federation 54496-2011. ISO 8692:2004 (2011) Water. Determination of toxicity with use of green freshwater unicellular algae. Standartinform, Moscow, 1\u0026ndash;53.\u003c/li\u003e\n\u003cli\u003ePetrunina EA, Loskutov SR, Ryazanova TV, Aniskina AA, Permyakova GV, Stasova VV (2022) Comparative analysis of physical-chemical properties of larch and pine bark: thermal analysis and analytical pyrolysis. Sib. J. For. Sci. 4:35\u0026ndash;49. https://doi.org/10.15372/SJFS20220405\u003c/li\u003e\n\u003cli\u003eState standard of the USSR 9517-76 (1977) Brown coals and hard coals. Methods for determination of humic acids yield. USSR State Committee for Standards, Moscow, 1\u0026ndash;5.\u003c/li\u003e\n\u003cli\u003eState standard of the USSR 26212-91 (1993) Soils. Determination of hydrolytic acidity by Kappen method modified by CINAO. USSR Committee for Standardization and Metrology, Moscow, 1\u0026ndash;5.\u003c/li\u003e\n\u003cli\u003eState standard of the USSR 27821-88 (1990) Soils. Determination of base absorption sum by Kappen method. USSR State Committee for Standards, Moscow, 1\u0026ndash;4.\u003c/li\u003e\n\u003cli\u003eState standard of the USSR 27894.3\u0026ndash;88 (1988) Peat and products of its processing for agriculture. Methods for determination of ammonia nitrogen. USSR State Committee for Standards, Moscow, 2\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eState standard of the USSR 27894.5-88 (1988) Peat and products of its processing for agriculture. Methods for determination of mobile forms of phosphorus. USSR State Committee for Standards, Moscow, 1\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eThe state and protection of the environment of the Russian Federation in 2022: state report (2023) Ministry of Natural Resources of Russia: Lomonosov Moscow State University, pp 185-186.\u003c/li\u003e\n\u003cli\u003eYue F, Zhang J, Xu J, Niu T, L\u0026uuml; X, Liu M (2022) Effects of monosaccharide composition on quantitative analysis of total sugar content by phenol-sulfuric acid method. Front. Nutr\u003cem\u003e.\u003c/em\u003e 9:963318. https://doi.org/10.3389/fnut.2022.963318\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"biotechnology-letters","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bile","sideBox":"Learn more about [Biotechnology Letters](https://www.springer.com/journal/10529)","snPcode":"10529","submissionUrl":"https://submission.nature.com/new-submission/10529/3","title":"Biotechnology Letters","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"bark-wood waste, microbial processing, soil, composting parameters","lastPublishedDoi":"10.21203/rs.3.rs-7628066/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7628066/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe issue of bark-wood waste (BWW) utilization is challenging for the regions adjacent to pulp and paper mills. Bark is difficult to recycle, and the additives used in paper production further complicate this process. This work focuses on the potential application of wood sawdust microbial transformation, the technology of which was developed at the Irkutsk Institute of Chemistry SB RAS, for the processing of bark-wood waste into environmentally safe soil. Laboratory experiments revealed that long-term stored BWW can undergo microbial degradation. The best results were obtained with the BWW/sawdust mixture. The substrate neutralization conditions were selected to simultaneously lower the pH and introduce the necessary mineral additives for microbial function. A semi-industrial experiment with a BWW/sawdust mixture of 20 m\u003csup\u003e3\u003c/sup\u003e (3:1 ratio) was performed. The experiment demonstrated that pH stabilization occurred more efficiently than in the laboratory experiment. A temperature increase, which is characteristic of aerobic processing of lignocellulosic waste was also observed. The product obtained was non-toxic to both plants and \u003cem\u003eChlorella vulgaris\u003c/em\u003e (hazard class 5). The processing improved of the agrochemical parameters of the substrate, such as hydrolytic acidity, cation exchange capacity, and the sum of absorbed bases. The increase in humic acid content indicates a deep microbial degradation of the lignin component of BWW. Consequently, the microbial transformation of BWW was successfully implemented to produce a non-toxic soil. This technology can be scaled up for large volumes of BWW at storage sites.\u003c/p\u003e","manuscriptTitle":"Application of wood sawdust microbial transformation for the utilization of long-term stored bark-wood waste","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-15 16:39:59","doi":"10.21203/rs.3.rs-7628066/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2025-12-06T08:18:45+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-02T19:53:42+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-19T12:41:47+00:00","index":"","fulltext":""},{"type":"submitted","content":"Biotechnology Letters","date":"2025-09-19T02:00:37+00:00","index":"","fulltext":""},{"type":"decision","content":"Major revisions","date":"2025-09-16T11:20:29+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"biotechnology-letters","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bile","sideBox":"Learn more about [Biotechnology Letters](https://www.springer.com/journal/10529)","snPcode":"10529","submissionUrl":"https://submission.nature.com/new-submission/10529/3","title":"Biotechnology Letters","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"203ceee1-2cf4-4c7c-bc80-0a2e4b9b5a36","owner":[],"postedDate":"October 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-13T16:16:22+00:00","versionOfRecord":{"articleIdentity":"rs-7628066","link":"https://doi.org/10.1007/s10529-026-03730-8","journal":{"identity":"biotechnology-letters","isVorOnly":false,"title":"Biotechnology Letters"},"publishedOn":"2026-04-10 15:58:20","publishedOnDateReadable":"April 10th, 2026"},"versionCreatedAt":"2025-10-15 16:39:59","video":"","vorDoi":"10.1007/s10529-026-03730-8","vorDoiUrl":"https://doi.org/10.1007/s10529-026-03730-8","workflowStages":[]},"version":"v1","identity":"rs-7628066","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7628066","identity":"rs-7628066","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}