Biodegradation of municipal plastic wastes collected from solid waste landfills of Jammu, India

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This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3224250/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Plastics are non-biodegradable, strong, durable, moisture resistant, light weight polymers of carbon along with hydrogen, nitrogen, sulphur, and other organic and inorganic elements and are manufactured from fossil fuel which is a non-renewable source. Low density polyethylene is the most commonly occurring non-biodegradable waste material which constitutes approximately 60% of the total plastic production. In the present study, an attempt has been made to isolate, screen, and characterize the most efficient polyethylene degrading bacteria by using partially degraded polyethylene samples with adhered soil collected from two municipal waste dumping grounds of Jammu region. A total of 62 bacterial isolates were obtained from different waste disposal sites were screened on synthetic Medium. Low density polyethylene powder was used as the sole carbon source in synthetic medium. The biodegradation activity of the isolates was investigated based on the percent weight loss and percent loss in tensile strength of the polyethylene. Maximum percent weight loss (%WL; 22.66) was recorded with MB57 after 2 months of shaking at room temperature. Maximum percent loss in tensile strength (% loss in TS; 74.35) was documented MB57. Further, the level of degradation was confirmed by scanning electron microscopic (SEM) analysis. In SEM analysis, scions/ crakes were found on the surface of the degraded polyethylene. Low density polyethylene Plastic waste Biodegradation Synthetic medium Figures Figure 1 Figure 2 Introduction Plastic was first developed in England in the 1850s, and is now widely used in all aspects of life and have gradually become an indispensable part (Zhuang 2022). Billions of virgin plastic products produced to date that are eventually discarded in the natural environment (Nielsen et al. 2020). Almost 6.3 billion tons of plastics were produced worldwide in 2015 and the number is increasing exponentially each year because of its efficient and versatile use (Yuan et al. 2020 ). In 2020 alone, the global plastic production has been nearly 400 million tons (Feil and Pretz 2020 ). India produces approximately 12 million tonnes of plastics every year while 9205 tonnes are recycled per day (Kartikey et al. 2016 ). The various forms of plastics continuously used in day-to-day life are nylon, polycarbonate, polyethylene-terephthalate, polyethylene, polypropylene, polystyrene, polytetraflouroethylene, polyurethane and polyvinyl chloride (Smith 1964 ). Polythene is a linear hydrocarbon polymers consisting of long chains of the ethylene monomers (C 2 H 4 ). The general formula of polyethylene is CnH 2 n, where ‘n’ is the number of carbon atoms (Bhaduri et al. 2008). Polythene is produced by an efficient catalytic polymerization of ethylene monomers of cheap petrochemical stocks of oil or gas (Fuhs 1961 ). Polyethylene is among the most commonly used material in making the shopping bags, plastic bottles, milk jugs, films, and toiletry bottles used in daily life (Romani et al. 2020 ). Non biodegradation of plastics causes widespread pollution due to their accumulation in the environment (Li et al. 2020b ). As per report due to plastic pollution in the marine environment minimum 267 species are being affected which includes all mammals, sea turtles (86%) and seabirds (44%). Plastic leads to the intestinal choking/blockage of the sea inhabitants and death of almost one million marine animals due to ingestion or entanglement (Shah et al. 2008 ). Polyethylene pollution in soils has become a serious problem due to widespread use of Polyethylene products in agricultural mulch, composite materials and packaging, coupled with improper recycling. The presence of polyethylene microplastics reduces the soil adsorption capacity, the particle size of aggregates, and the diversity of bacteria and fungi (Hoe et al. 2021). The plastic sheets or bags do not allow water and air to go into the earth which causes soil infertility (Starnecker et al. 1996). Small plastic particles even accumulate around seed pores, delaying the germination and growth of terrestrial vascular plants (Bosker et al. 2019 ). In the landfill plastic does not degrade for thousands of years, causing infertility in land and environmentally unsafe for its inhabitants (Sarker et al. 2011). Three types of polymer degradation methods are there in the literature such as photodegradation, thermo- oxidative degradation and biodegradation. The biodegradation is a natural process of degrading materials by microbes such as bacteria, fungi and algae (Sangle et al. 2012). The main motive of this mechanism of polythene (PE) degradation is to initiate first abiotic oxidation (photo or thermo) followed by microbial biodegradation (Abrusci et al. 2011 ). During the biodegradation of plastics, microorganisms firstly decrease the molecular weight of the plastics, followed by the transformation of the polymer to its monomers. Monomers are then broken down in a process of mineralization with the release carbon dioxide, water, and methane (Zheng 2005). The process of plastic degradation by microbes is due the activity of certain microbial enzymes (Usha et al. 2011 ). In the first step, there is adhesion of microbial enzyme to the polyethylene substrate followed by the hydrolytic cleavage. Microbial enzymes that lead to biodegradation of polyethylene are identified to be proteases, lipases, cutinases, laccases, manganese peroxidases, lignin peroxidases, alkane hydroxylases, etc., (Ahmed et al. 2018 ). Some of the important bacteria reported for the biodegradation of LDPE includes, Bacillus spp., Pseudomonas spp., Streptomyces spp., Rhodococcus sp., Acinetobacter sp., Brevibacillus sp., Flavobacterium spp., Ralstonia spp., Staphylococcus spp., Stenotrophomonas spp., Micrococus spp., Microbacterium sp. and Nocardia sp. (Harshvardhan et al. 2013). The main aim of the work is to isolate, identify, and characterize the bacteria from dumped soil area and screening of the potential plastic degrading bacteria and identifying the high potential bacteria that degrade the plastics. Materials and methods Collection of polyethylene samples The partially degraded polyethylene samples with adhered soil were collected in sterile zip lock bags at a depth of 3–5 cm from the municipal waste dumping grounds of kot Balwal (Lat.32.7266°N and Lon.74.8570°E) and Bagwati Nagar (Lat.32.7287°N and Lon.74.8368°E) of Jammu region. The samples were labelled, sealed properly and transported to the laboratory for further processing and stored at 4°C aseptically. All the samples were processed within 24 hours of collection. Preparation of polyethylene powder LDPE samples were collected from industrial area Gangyal, Jammu. The polyethylene sheets were cut into small pieces and immersed in xylene followed by boiling for 5–15 minutes to dissolves completely. The resulting residue was crushed by hands wearing gloves. The crushed residue was washed with ethanol 2–3 times to remove the residual xylene. The polyethylene powder thus obtained was kept for evaporation of ethanol and then dried overnight in hot air oven at 60 \(℃\) . Finally, the polyethylene powder was stored at room temperature Isolation of bacteria 1g of soil sample was serial diluted from 10 − 1 to 10 − 9 and inoculated in sterilized Synthetic Medium(SM). SM contains the following constitutions in 1000ml distilled water, K 2 HPO 4 , 1g; KH 2 PO 4 , 0.2g; NaCl, 1g; CaCl 2 .2H 2 O, 0.002g; (NH 4 ) 2 SO, 1g; MgSO 4 .7H 2 O, 0.5g; CuSO 4 .5H 2 O, 0.001g; ZnSO 4 .7H 2 O, 0.001g; MnSO 4 .H 2 O, 0.001g and FeSO 4 .7H 2 O, 0.01g. 100mg of LDPE powder was added and then Incubated at room temperature for 1 week. During seven days all other microbes died except of those who had capacity to degrade polymer. 0.1ml of inoculum from synthetic medium were transferred into the sterile nutrient agar with the help of sterile micropipette and were plated using L-rod by spread plate method. The nutrient agar was incubated at 37 \(℃\) for 24 hrs to get the isolated colonies. The pure cultures were obtained by streak plate technique (Aneja 2003 ). Screening of LDPE degrading bacteria: As per the protocol of Sharma and Sharma ( 2004 ), pretreatment of the PE strips was carried out to remove the additive if any. Preweighed plastic strips of size 2x2 cm was taken, washed with distilled water and then with acetone. Each plastic strips were weighed using weighing balance, dried, sterilized followed by UV treatment for 15–20 min in laminar air flow. 50ml of nutrient broth was taken in each flask for bacterial degradation. Control was maintained with plastic discs in the microbe free medium. Different flasks were maintained for each treatment. One millilitre of 2-day-old bacterial culture was transferred to each flask. After inoculation, all the cultures were placed on orbital rotary shaker at the speed of 140 ± 20 rpm at room temperature for a period of 2 months. After 2 months of incubation, the screening of the polyethylene degrading bacterial isolates was carried out based on the percent weight loss and percent loss in tensile strength of the polyethylene. Screening of the polyethylene degrading bacterial isolates based on percent weight loss At the end of 2-month incubation, the degraded polyethylene strips were harvested from each flask aseptically in separate petri dishes followed by washing with absolute alcohol (once) and tap water (twice). After washing, all the polyethylene strips were dried in oven overnight at 40°C. The dried PE strips were weighed, and the percent weight loss was calculated using the formula Initial weight where X is the average initial weight (mg) and Y is the average final weight after 2 months. Screening of the polyethylene degrading bacterial isolates based on percent loss in tensile strength The changes in the tensile strength (N/mm 2 ) of degraded polyethylene strips by the bacterial isolates after 2 months of incubation was determined using the tensile testing machine (Universal testing machine), as per the method of ASTM(2012) at Shri Mata Vaishno Devi University ( SMVDU ), Katra. The percent loss in tensile strength (% loss in TS) was calculated using the formula where X is the average TS of the pretreated polyethylene strips before the experiment (N/mm 2 ) and Y is the average TS after 2 months. After 2 months of incubation period, percent loss in TS was determined. Scanning electron microscopy analysis PE with maximum percent weight loss (after 2 months), PE strips with maximum percent loss in TS (after 2 months), and pretreated PE strips (after 2 months of shaking in NA media as a control) were used for SEM ( Central University of Jammu ) analysis. For SEM analysis, sample preparation was carried out as per Kyaw et al. (2012) followed by gold coating before taking images. Results and discussion The present study deals with the isolation, screening, identification, and ability of plastic degrading bacteria isolated from dumped garbage soil. The samples were subcultured from the collected municipal waste samples. Pure cultures were recovered from serial dilution followed by spread plate technique. In this study a total of 62 bacterial isolates were recorded from two municipal waste dumping sites. Maximum 33 isolates were recorded from the Kot Balwal dumping site followed by 29 bacterial isolates from Bagwati Nagar dumping sites. Out of 62 bacterial isolates obtained from garbage dumping sites three isolates MB 5, MB 12 and MB 57, showed polyethylene biodegradation ability by utilizing polyethylene as the sole carbon source. Through Gram’s staining technique, a two isolates were identified as gram negative bacterial strains (MB5, MB 57) and one isolate as gram positive (MB12).The isolates obtained were subjected to standard biochemical tests (catalase test, citrate test, Vogues proskeur’s test, urease test, Nitrate reduction test, Phenylalanine deamination test, Glucose utilization Lactose utilization and Sorbitol utilization test). The biodegradation of polythylene was analyzed using plastic strips which were aseptically transferred into the liquid nutrient broth containing bacteria and it was observed for 2 months for percent weight loss and percent loss in tensile strength. After 2 months of incubation at room temperature, the % WL of the polyethylene strips was calculated. Among 2 dumping sites, all the 62 bacterial isolates do not possess the potential to degrade polyethylene strips. Among 62, only three isolates (MB 5, MB 12 and MB 57) lead to more than 10% WL. Maximum % WL (22.66) was recorded with MB57 followed by MB 5 and MB 12 (table 1.). Tensile strength of all the polythylene strips was also determined. Not all 62 bacterial isolates lead to reduction of tensile strength of the polythylene. Only 3 bacterial isolates reports loss in tensile strength (Fig. 1 ) as compared to control (pretreated PE strips). Maximum % loss of TS (74.35%) was recorded with MB57 followed by MB 5 and MB 12 (table 2.). The SEM images reported the crack/holes/scions on the surface of the polythylene degraded by bacteria (both by %WL and % loss in TS). The SEM analysis confirms the biodegradation of the polythylene (Fig. 2 ). A similar study previously conducted by (Usha et al. 2011 ) included biodegradation of polythene bag and plastic cups which were analysed by 2, 4, and 6 month of incubation in liquid culture method respectively. The microbial species associated with the polythene materials were identified as Pseudomonas sp., Bacillus sp., Staphylococcus sp., Aspergillus nidulans, Aspergillus flavus , and Streptomyces sp. Their results concluded that, among the bacteria Pseudomonas sp., degrade faster compared to Streptomyces species. Vijaya and Reddy ( 2008 ) recorded 2.87% WL (HDPE1), 4.48% WL (HDPE1), 11.54% WL (LDPE1), and 10.47% WL (LDPE2) in different types of polythene after 12 months of compositing in soil mixed with municipal solid waste and identified the mixture of bacteria and fungi from the plastic and cup films. Among the bacteria, the most dominant genera were Bacillus sp., Staphylococcus sp., Streptococuus sp., and Moraxella sp. (Vijaya and Reddy 2008 ). Shahnawaz (2016) recorded a total of 123 bacterial isolates from west coast of India. Maximum percent weight loss (%WL; 21.87 ± 6.37%) was recorded with VASB14 after 2 months of shaking at room temperature. Maximum percent loss in tensile strength (% loss in TS; 87.50 ± 4.8%) was documented with VASB1.The most efficient polythene degrading bacteria were identified as L. fusiformis strainVASB14/WL and Bacillus cereus strain VASB1/TS. Hence, from this study, it can be speculated that microbes have enough potential to degrade plastic with due course of time. The following work reveals that waste disposal sites may contains a vast majority of microbes and that bacteria possess plastic degrading potential and plastic waste problem can be efficiently managed with these organisms. The present study reveals that 3 bacterial isolates have the ability to degrade LDPE as the soul carbon source. Research towards engineering the microbes at genetic level to increase its plastic degrading capability should be the priority in future days. Table.1 Percent weight loss of polyethylene strips with efficient bacterial isolates in mg after 60 days of incubation S. No Bacterial Isolates Initial weight (mg) Final weight (mg) Total weight loss (mg) Percent weight loss (%) 1. MB5 0.030 0.0255 0.0045 15.00% 2. MB12 0.030 0.0261 0.0039 13.00% 3. MB57 0.030 0.0232 0.0068 22.66% Table.2 Percent tensile strength loss of polyethylene strips with efficient bacterial isolates in N/mm 2 after 60 days of incubation S.No Bacterial Isolates Initial strength (N/mm 2 ) Final strength (N/mm 2 ) Percent tensile strength loss (%) 1. MB-5 1.95 1.5 23.07. 2. MB-12 1.95 1.7 12.82 3. MB-57 1.95 0.5 74.35 References Abrusci C, Pablos JL, Corrales T, López-Marín J, Marína I, Catalina F (2011) Biodegradation of photo-degraded mulching films based on polyethylenes and stearates of calcium and iron as pro-oxidant additives. Int Biodeter Biodegr 65:451–459. doi:10.1016/j.ibiod.2010.10.012. Ahmed T, Shahid M, Azeem F, Rasul I, Shah AA, Noman M et al (2018) Biodegradation of plastics: Current scenario and future prospects for environmental safety. Environ Sci Pollut Res; 25:7287-98. Aneja KR (2003) Experiments in microbiology, plant pathology and biotechnology, 4th edn. New Age International, New Delhi. Arutchelvi J, Sudhakar M, Arkatkar A, Doble M, Bhaduri S et al (2008) Biodegradation of polyethylene and polypropylene. Indian J Biotechnol 7: 9-22. Bosker T, Bouwman J, Brun NR, Behrens P, Vijver, MG (2019) Microplastics accumulate on pores in seed capsule and delay germination and root growth of the terrestrial vascular plant Lepidium sativum. Chemosphere 226:774 781. doi:10.1016/j.chemosphere.2019.03.163. Feil A, Pretz T (2020) Mechanical recycling of packaging waste. Plastic Waste and Recycling Elsevier, pp. 283–319. https://doi.org/10.1016/B978-0-12-817880- 5.00011-6. Fuhs GW (1961) Der mikrobielle Abbau von Kohlenwasserstoffen. Arch Microbiol 39:374–422. Harshvardhan K, Jha B (2013) Biodegradation of low-density polyethylene by marine bacteria from pelagic waters, Arabian Sea, India. Marine Poll Bull. 77(1): 100-106. Hou. J, Xu. X, Yu. H, Xi. B, Tan. W (2021) Comparing the long-term responses of soil microbial structures and diversities to polyethylene microplastics in different aggregate fractions. Environ. Int., 149, Article 106398, 10.1016/j.envint.2021.106398. Kartikey KG, Deepa D, Deepanshu R (2016) Isolation and screening of low density polyethylene (LDPE) degrading bacterial strains from waste disposal sites. World Journal of Pharmaceutical Research 5(11): 1633-1643. Kyaw BM, Champakalakshmi R, SakharkarMK, Lim CS, Sakharkar KR (2012) Biodegradation of low density polythene (LDPE) by Pseudomonas species. Indian J Microbio doi:10.1007/s12088-012-0250-6 Li Z, Wei R, Gao M, Ren Y, Yu, Nie, K, Xu H, Liu (2020b) Biodegradation of low-density polyethylene by Microbulbifer hydrolyticus IRE-31. J. Environ. Manag. 263, 110402 https://doi.org/10.1016/j.jenvman.2020.110402. Nelson B, What can 28,000 Rubber Duckies Lost at Sea Teach Us about Our Oceans. Vol. 3. Atlanta: Mother Nature Network; 2011. p. 1. Romani VP, Martins VG, Goddard JM (2020) Radical scavenging polyethylene films as antioxidant active packaging materials. Food Control 109, 106946. https://doi. org/10.1016/j.foodcont.2019.106946. Sangale M, Shahnawaz M, Ade A (2012) A review on biodegradation of polythene: the microbial approach. http://dx.doi.org/10.4172/2155-6199.1000164. Sarker M (2011) Converting waste plastic to hydrocarbon fuel materials. Energy Engineering 108(2):35–43. doi:10.1080/01998595.2011.10389018. Shah AA, Hasan F, Hameed A, Ahmed S (2008) Biological degradation of plastics: a comprehensive review. Biotechnol Adv 26:246–265. doi:10.1016/j.biotechadv.2007.12.005. Shahnawaz M, Manisha KS, Avinash B (2016) Bacteria-based polythene degradation products: GC-MS analysis and toxicity testing. International Research Journal of Environment Sciences 4(11): 58-61. Sharma A, Sharma A (2004) Degradation assessment of low density polythene (LDP) and polythene (PP) by an indigenous isolate of Pseudomonas stutzeri. J Sci Ind Res 63:293–296. Smith WM (1964) Manufacture of plastic, Volume 1. Technology and Engineering, Reinhold Pub. Corp, USA. Starnecker A, Menner M (1996) Assessment of biodegradability of plastics under stimulated composting conditions in a laboratory test system. International Biodeterioration & Biodegradation 37(1-2): 85-92. Usha R, Sangeetha T, Palaniswamy M (2011) Screening of Polyethylene Degrading Microorganisms from Garbage Soil. Libyan Agricultural Research Center Journal International 2(4): 200-204. Vijaya C, Reddy RM (2008) Impact of soil composting using municipal solid waste on biodegradation of plastics. Indian J Biotechnol 7:235–239. Yuan J, Ma J, Sun Y, Zhou T, Zhao Y, and Yu F (2020) Microbial degradation and other environmental aspects of microplastics/plastics. Sci. Total Environ. 715:136968. doi: 10.1016/j.scitotenv.2020.136968 Zheng Y, Yanful EK, Bassi AS (2005) A review of plastic waste biodegradation. Crit Rev Biotechnol; 25:243-50. Zhuang Yao, Hyeon Jeong Seong, Yu-Sin Jang (2022) Environmental toxicity and decompsition of polyethylene. Ecotoxicology and Environmental Safety 242 (2022) 113933. https://doi.org/10.1016/j.ecoenv.2022.113933 Additional Declarations No competing interests reported. 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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-3224250","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":223285416,"identity":"9a169b87-cc72-4262-9121-7a0297b1d56e","order_by":0,"name":"Brajeshwar singh","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYBACAwg+kAAkGB8AGUjiRGhhNiBaCwNUC5sEQgseYC59+EHBhz938szZz5hV89TckeNnYH74gKHgDk4tln1pBoYz254VW/bkmN3mOfbMWLKBzdiAweAZboedYTAw5m04nLjhAEgLG4jBA3ShwWE8Wtg/GP/5A1R5/o1ZMc8/orTwGBgzgAy/kWPGzNtGhBbLHp4Cw962w8UGN54VS87tO2ws2Qz0SwIeLeY87NsMfvw5nGdwPnnjhzffDsvxszc/fPDhD24tQMAGjzYmHhDJDMQJ+DQAlTyAsRh/4Fc5CkbBKBgFIxQAAIl9WyE8U2UCAAAAAElFTkSuQmCC","orcid":"","institution":"Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu","correspondingAuthor":true,"prefix":"","firstName":"Brajeshwar","middleName":"","lastName":"singh","suffix":""},{"id":223285417,"identity":"c8d868b3-5f8a-4f94-a546-352c76894ed0","order_by":1,"name":"Ankita Sharma","email":"","orcid":"","institution":"Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu","correspondingAuthor":false,"prefix":"","firstName":"Ankita","middleName":"","lastName":"Sharma","suffix":""},{"id":223285418,"identity":"98816460-478c-4df7-9fb8-ca765fd4fbb1","order_by":2,"name":"Vironika .","email":"","orcid":"","institution":"Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu","correspondingAuthor":false,"prefix":"","firstName":"Vironika","middleName":"","lastName":".","suffix":""}],"badges":[],"createdAt":"2023-08-01 11:44:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3224250/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3224250/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":41195665,"identity":"84874859-2284-4b23-aebf-c30416e51aab","added_by":"auto","created_at":"2023-08-07 16:14:17","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":34778,"visible":true,"origin":"","legend":"\u003cp\u003eGraphical presentation of percent loss in tensile strength of polyethylene strips with most efficient bacterial isolates after 60 days of incubation:\u003c/p\u003e\n\u003cp\u003ea. Control- pretreated polyethylene strips,\u003c/p\u003e\n\u003cp\u003eb. % loss in tensile strength of polyethylene strip by bacterial isolate MB 5 ( 23.07% TS loss)\u003c/p\u003e\n\u003cp\u003ec. % loss in tensile strength of polyethylene strip by bacterial isolate MB12 (12.82%TS loss)\u003c/p\u003e\n\u003cp\u003ed. % loss in tensile strength of polyethylene strip by bacterial isolate MB57(74.35%TS loss)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3224250/v1/fa121976bc9085039d7bfe51.png"},{"id":41197610,"identity":"6f0cad0b-4cb5-42bc-99bf-af23b50bd28a","added_by":"auto","created_at":"2023-08-07 16:22:17","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":255784,"visible":true,"origin":"","legend":"\u003cp\u003eScanning electron microscopy (SEM) images of the polyethylene biodegradation with most efficient bacterial isolates after 60 days of incubation:\u003c/p\u003e\n\u003cp\u003ea. Control- pretreated polyethylene strips\u003c/p\u003e\n\u003cp\u003eb. biodegradation of polyethylene strips by bacterial isolate MB 5\u003c/p\u003e\n\u003cp\u003ec. biodegradation of polyethylene strips by bacterial isolate MB 12\u003c/p\u003e\n\u003cp\u003ed. biodegradation of polyethylene strips by bacterial isolate MB 57\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3224250/v1/dff449fdc561e58d4d9e5e85.png"},{"id":43797914,"identity":"901d5153-2c91-4352-9f63-5db3e003c488","added_by":"auto","created_at":"2023-09-28 00:22:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":614220,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3224250/v1/8486c675-7bee-4895-bda0-873e9ecd5f1a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Biodegradation of municipal plastic wastes collected from solid waste landfills of Jammu, India","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePlastic was first developed in England in the 1850s, and is now widely used in all aspects of life and have gradually become an indispensable part (Zhuang 2022). Billions of virgin plastic products produced to date that are eventually discarded in the natural environment (Nielsen et al. 2020). Almost 6.3\u0026nbsp;billion tons of plastics were produced worldwide in 2015 and the number is increasing exponentially each year because of its efficient and versatile use (Yuan et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In 2020 alone, the global plastic production has been nearly 400\u0026nbsp;million tons (Feil and Pretz \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). India produces approximately 12\u0026nbsp;million tonnes of plastics every year while 9205 tonnes are recycled per day (Kartikey et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). The various forms of plastics continuously used in day-to-day life are nylon, polycarbonate, polyethylene-terephthalate, polyethylene, polypropylene, polystyrene, polytetraflouroethylene, polyurethane and polyvinyl chloride (Smith \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e1964\u003c/span\u003e). Polythene is a linear hydrocarbon polymers consisting of long chains of the ethylene monomers (C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e). The general formula of polyethylene is CnH\u003csub\u003e2\u003c/sub\u003en, where \u0026lsquo;n\u0026rsquo; is the number of carbon atoms (Bhaduri et al. 2008). Polythene is produced by an efficient catalytic polymerization of ethylene monomers of cheap petrochemical stocks of oil or gas (Fuhs \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e1961\u003c/span\u003e). Polyethylene is among the most commonly used material in making the shopping bags, plastic bottles, milk jugs, films, and toiletry bottles used in daily life (Romani et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Non biodegradation of plastics causes widespread pollution due to their accumulation in the environment (Li et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2020b\u003c/span\u003e). As per report due to plastic pollution in the marine environment minimum 267 species are being affected which includes all mammals, sea turtles (86%) and seabirds (44%). Plastic leads to the intestinal choking/blockage of the sea inhabitants and death of almost one million marine animals due to ingestion or entanglement (Shah et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). Polyethylene pollution in soils has become a serious problem due to widespread use of Polyethylene products in agricultural mulch, composite materials and packaging, coupled with improper recycling. The presence of polyethylene microplastics reduces the soil adsorption capacity, the particle size of aggregates, and the diversity of bacteria and fungi (Hoe et al. 2021). The plastic sheets or bags do not allow water and air to go into the earth which causes soil infertility (Starnecker et al. 1996). Small plastic particles even accumulate around seed pores, delaying the germination and growth of terrestrial vascular plants (Bosker et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). In the landfill plastic does not degrade for thousands of years, causing infertility in land and environmentally unsafe for its inhabitants (Sarker et al. 2011). Three types of polymer degradation methods are there in the literature such as photodegradation, thermo- oxidative degradation and biodegradation. The biodegradation is a natural process of degrading materials by microbes such as bacteria, fungi and algae (Sangle et al. 2012). The main motive of this mechanism of polythene (PE) degradation is to initiate first abiotic oxidation (photo or thermo) followed by microbial biodegradation (Abrusci et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). During the biodegradation of plastics, microorganisms firstly decrease the molecular weight of the plastics, followed by the transformation of the polymer to its monomers. Monomers are then broken down in a process of mineralization with the release carbon dioxide, water, and methane (Zheng 2005). The process of plastic degradation by microbes is due the activity of certain microbial enzymes (Usha et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). In the first step, there is adhesion of microbial enzyme to the polyethylene substrate followed by the hydrolytic cleavage. Microbial enzymes that lead to biodegradation of polyethylene are identified to be proteases, lipases, cutinases, laccases, manganese peroxidases, lignin peroxidases, alkane hydroxylases, etc., (Ahmed et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Some of the important bacteria reported for the biodegradation of LDPE includes, \u003cem\u003eBacillus\u003c/em\u003e spp., \u003cem\u003ePseudomonas\u003c/em\u003e spp., \u003cem\u003eStreptomyces\u003c/em\u003e spp., \u003cem\u003eRhodococcus\u003c/em\u003e sp., \u003cem\u003eAcinetobacter\u003c/em\u003e sp., \u003cem\u003eBrevibacillus\u003c/em\u003e sp., \u003cem\u003eFlavobacterium\u003c/em\u003e spp., \u003cem\u003eRalstonia\u003c/em\u003e spp., \u003cem\u003eStaphylococcus\u003c/em\u003e spp., \u003cem\u003eStenotrophomonas\u003c/em\u003e spp., \u003cem\u003eMicrococus\u003c/em\u003e spp., \u003cem\u003eMicrobacterium\u003c/em\u003e sp. and \u003cem\u003eNocardia\u003c/em\u003e sp. (Harshvardhan et al. 2013). The main aim of the work is to isolate, identify, and characterize the bacteria from dumped soil area and screening of the potential plastic degrading bacteria and identifying the high potential bacteria that degrade the plastics.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003eCollection of polyethylene samples\u003c/h2\u003e\n \u003cp\u003eThe partially degraded polyethylene samples with adhered soil were collected in sterile zip lock bags at a depth of 3\u0026ndash;5 cm from the municipal waste dumping grounds of kot Balwal (Lat.32.7266\u0026deg;N and Lon.74.8570\u0026deg;E) and Bagwati Nagar (Lat.32.7287\u0026deg;N and Lon.74.8368\u0026deg;E) of Jammu region. The samples were labelled, sealed properly and transported to the laboratory for further processing and stored at 4\u0026deg;C aseptically. All the samples were processed within 24 hours of collection.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003ePreparation of polyethylene powder\u003c/h2\u003e\n \u003cp\u003eLDPE samples were collected from industrial area Gangyal, Jammu. The polyethylene sheets were cut into small pieces and immersed in xylene followed by boiling for 5\u0026ndash;15 minutes to dissolves completely. The resulting residue was crushed by hands wearing gloves. The crushed residue was washed with ethanol 2\u0026ndash;3 times to remove the residual xylene. The polyethylene powder thus obtained was kept for evaporation of ethanol and then dried overnight in hot air oven at 60\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(℃\\)\u003c/span\u003e\u003c/span\u003e. Finally, the polyethylene powder was stored at room temperature\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003eIsolation of bacteria\u003c/h2\u003e\n \u003cp\u003e1g of soil sample was serial diluted from 10\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 10\u003csup\u003e\u0026minus;\u0026thinsp;9\u003c/sup\u003e and inoculated in sterilized Synthetic Medium(SM). SM contains the following constitutions in 1000ml distilled water, K\u003csub\u003e2\u003c/sub\u003eHPO\u003csub\u003e4\u003c/sub\u003e, 1g; KH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e, 0.2g; NaCl, 1g; CaCl\u003csub\u003e2\u003c/sub\u003e.2H\u003csub\u003e2\u003c/sub\u003eO, 0.002g; (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003eSO, 1g; MgSO\u003csub\u003e4\u003c/sub\u003e.7H\u003csub\u003e2\u003c/sub\u003eO, 0.5g; CuSO\u003csub\u003e4\u003c/sub\u003e.5H\u003csub\u003e2\u003c/sub\u003eO, 0.001g; ZnSO\u003csub\u003e4\u003c/sub\u003e.7H\u003csub\u003e2\u003c/sub\u003eO, 0.001g; MnSO\u003csub\u003e4\u003c/sub\u003e.H\u003csub\u003e2\u003c/sub\u003eO, 0.001g and FeSO\u003csub\u003e4\u003c/sub\u003e.7H\u003csub\u003e2\u003c/sub\u003eO, 0.01g. 100mg of LDPE powder was added and then Incubated at room temperature for 1 week. During seven days all other microbes died except of those who had capacity to degrade polymer. 0.1ml of inoculum from synthetic medium were transferred into the sterile nutrient agar with the help of sterile micropipette and were plated using L-rod by spread plate method. The nutrient agar was incubated at 37\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(℃\\)\u003c/span\u003e\u003c/span\u003e for 24 hrs to get the isolated colonies. The pure cultures were obtained by streak plate technique (Aneja \u003cspan class=\"CitationRef\"\u003e2003\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003eScreening of LDPE degrading bacteria:\u003c/h2\u003e\n \u003cp\u003eAs per the protocol of Sharma and Sharma (\u003cspan class=\"CitationRef\"\u003e2004\u003c/span\u003e), pretreatment of the PE strips was carried out to remove the additive if any. Preweighed plastic strips of size 2x2 cm was taken, washed with distilled water and then with acetone. Each plastic strips were weighed using weighing balance, dried, sterilized followed by UV treatment for 15\u0026ndash;20 min in laminar air flow. 50ml of nutrient broth was taken in each flask for bacterial degradation. Control was maintained with plastic discs in the microbe free medium. Different flasks were maintained for each treatment. One millilitre of 2-day-old bacterial culture was transferred to each flask. After inoculation, all the cultures were placed on orbital rotary shaker at the speed of 140\u0026thinsp;\u0026plusmn;\u0026thinsp;20 rpm at room temperature for a period of 2 months. After 2 months of incubation, the screening of the polyethylene degrading bacterial isolates was carried out based on the percent weight loss and percent loss in tensile strength of the polyethylene.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003ch2\u003eScreening of the polyethylene degrading bacterial isolates based on percent weight loss\u003c/h2\u003e\n \u003cp\u003eAt the end of 2-month incubation, the degraded polyethylene strips were harvested from each flask aseptically in separate petri dishes followed by washing with absolute alcohol (once) and tap water (twice). After washing, all the polyethylene strips were dried in oven overnight at 40\u0026deg;C. The dried PE strips were weighed, and the percent weight loss was calculated using the formula Initial weight\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/122228_c8a1650c59388082/122228_custom_files/img1691393913.png\"\u003e\u003cbr\u003e\u003c/p\u003e\n \u003cp\u003ewhere X is the average initial weight (mg) and Y is the average final weight after 2 months.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003eScreening of the polyethylene degrading bacterial isolates based on percent loss in tensile strength\u003c/h2\u003e\n \u003cp\u003eThe changes in the tensile strength (N/mm\u003csup\u003e2\u003c/sup\u003e) of degraded polyethylene strips by the bacterial isolates after 2 months of incubation was determined using the tensile testing machine (Universal testing machine), as per the method of ASTM(2012) at \u003cem\u003eShri Mata Vaishno Devi University\u003c/em\u003e (\u003cem\u003eSMVDU\u003c/em\u003e), Katra. The percent loss in tensile strength (% loss in TS) was calculated using the formula\u003c/p\u003e\n \u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/122228_c8a1650c59388082/122228_custom_files/img1691393943.png\"\u003e\u003c/p\u003e\n \u003cp\u003ewhere X is the average TS of the pretreated polyethylene strips before the experiment (N/mm\u003csup\u003e2\u003c/sup\u003e) and Y is the average TS after 2 months. After 2 months of incubation period, percent loss in TS was determined.\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eScanning electron microscopy analysis\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003ePE with maximum percent weight loss (after 2 months), PE strips with maximum percent loss in TS (after 2 months), and pretreated PE strips (after 2 months of shaking in NA media as a control) were used for SEM (\u003cem\u003eCentral University of Jammu\u003c/em\u003e) analysis. For SEM analysis, sample preparation was carried out as per Kyaw et al. (2012) followed by gold coating before taking images.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results and discussion","content":"\u003cp\u003eThe present study deals with the isolation, screening, identification, and ability of plastic degrading bacteria isolated from dumped garbage soil. The samples were subcultured from the collected municipal waste samples. Pure cultures were recovered from serial dilution followed by spread plate technique. In this study a total of 62 bacterial isolates were recorded from two municipal waste dumping sites. Maximum 33 isolates were recorded from the Kot Balwal dumping site followed by 29 bacterial isolates from Bagwati Nagar dumping sites. Out of 62 bacterial isolates obtained from garbage dumping sites three isolates MB 5, MB 12 and MB 57, showed polyethylene biodegradation ability by utilizing polyethylene as the sole carbon source. Through Gram\u0026rsquo;s staining technique, a two isolates were identified as gram negative bacterial strains (MB5, MB 57) and one isolate as gram positive (MB12).The isolates obtained were subjected to standard biochemical tests (catalase test, citrate test, Vogues proskeur\u0026rsquo;s test, urease test, Nitrate reduction test, Phenylalanine deamination test, Glucose utilization Lactose utilization and Sorbitol utilization test). The biodegradation of polythylene was analyzed using plastic strips which were aseptically transferred into the liquid nutrient broth containing bacteria and it was observed for 2 months for percent weight loss and percent loss in tensile strength. After 2 months of incubation at room temperature, the % WL of the polyethylene strips was calculated. Among 2 dumping sites, all the 62 bacterial isolates do not possess the potential to degrade polyethylene strips. Among 62, only three isolates (MB 5, MB 12 and MB 57) lead to more than 10% WL. Maximum % WL (22.66) was recorded with MB57 followed by MB 5 and MB 12 (table 1.). Tensile strength of all the polythylene strips was also determined. Not all 62 bacterial isolates lead to reduction of tensile strength of the polythylene. Only 3 bacterial isolates reports loss in tensile strength (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e) as compared to control (pretreated PE strips). Maximum % loss of TS (74.35%) was recorded with MB57 followed by MB 5 and MB 12 (table 2.). The SEM images reported the crack/holes/scions on the surface of the polythylene degraded by bacteria (both by %WL and % loss in TS). The SEM analysis confirms the biodegradation of the polythylene (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). A similar study previously conducted by (Usha et al. \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e) included biodegradation of polythene bag and plastic cups which were analysed by 2, 4, and 6 month of incubation in liquid culture method respectively. The microbial species associated with the polythene materials were identified as \u003cem\u003ePseudomonas\u003c/em\u003e sp., \u003cem\u003eBacillus\u003c/em\u003e sp., \u003cem\u003eStaphylococcus\u003c/em\u003e sp., \u003cem\u003eAspergillus nidulans, Aspergillus flavus\u003c/em\u003e, and \u003cem\u003eStreptomyces\u003c/em\u003e sp. Their results concluded that, among the bacteria \u003cem\u003ePseudomonas\u003c/em\u003e sp., degrade faster compared to \u003cem\u003eStreptomyces\u003c/em\u003e species. Vijaya and Reddy (\u003cspan class=\"CitationRef\"\u003e2008\u003c/span\u003e) recorded 2.87% WL (HDPE1), 4.48% WL (HDPE1), 11.54% WL (LDPE1), and 10.47% WL (LDPE2) in different types of polythene after 12 months of compositing in soil mixed with municipal solid waste and identified the mixture of bacteria and fungi from the plastic and cup films. Among the bacteria, the most dominant genera were Bacillus sp., Staphylococcus sp., Streptococuus sp., and Moraxella sp. (Vijaya and Reddy \u003cspan class=\"CitationRef\"\u003e2008\u003c/span\u003e). Shahnawaz (2016) recorded a total of 123 bacterial isolates from west coast of India. Maximum percent weight loss (%WL; 21.87\u0026thinsp;\u0026plusmn;\u0026thinsp;6.37%) was recorded with VASB14 after 2 months of shaking at room temperature. Maximum percent loss in tensile strength (% loss in TS; 87.50\u0026thinsp;\u0026plusmn;\u0026thinsp;4.8%) was documented with VASB1.The most efficient polythene degrading bacteria were identified as L. fusiformis strainVASB14/WL and Bacillus cereus strain VASB1/TS. Hence, from this study, it can be speculated that microbes have enough potential to degrade plastic with due course of time. The following work reveals that waste disposal sites may contains a vast majority of microbes and that bacteria possess plastic degrading potential and plastic waste problem can be efficiently managed with these organisms. The present study reveals that 3 bacterial isolates have the ability to degrade LDPE as the soul carbon source. Research towards engineering the microbes at genetic level to increase its plastic degrading capability should be the priority in future days.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable.1\u003c/strong\u003e Percent weight loss of polyethylene strips with efficient bacterial isolates in mg after 60 days of incubation\u003c/p\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003ctable id=\"Taba\" border=\"1\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS. No\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eBacterial Isolates\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eInitial weight (mg)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFinal weight (mg)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTotal weight loss (mg)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePercent weight loss (%)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMB5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.030\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0255\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0045\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e15.00%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMB12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.030\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0261\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0039\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e13.00%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMB57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.030\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0232\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.0068\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.66%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable.2\u003c/strong\u003e Percent tensile strength loss of polyethylene strips with efficient bacterial isolates in N/mm\u003csup\u003e2\u003c/sup\u003e after 60 days of incubation\u003c/p\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003ctable id=\"Tabb\" border=\"1\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS.No\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eBacterial Isolates\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eInitial strength (N/mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFinal strength (N/mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePercent tensile strength loss (%)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMB-5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e23.07.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMB-12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e12.82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMB-57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e74.35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAbrusci C, Pablos JL, Corrales T, L\u0026oacute;pez-Mar\u0026iacute;n J, Mar\u0026iacute;na I, Catalina F (2011) Biodegradation of photo-degraded mulching films based on polyethylenes and stearates of calcium and iron as pro-oxidant additives. Int Biodeter Biodegr 65:451\u0026ndash;459. doi:10.1016/j.ibiod.2010.10.012.\u003c/li\u003e\n\u003cli\u003eAhmed T, Shahid M, Azeem F, Rasul I, Shah AA, Noman M et al (2018)\u003cem\u003e \u003c/em\u003eBiodegradation of plastics: Current scenario and future prospects for environmental safety. Environ Sci Pollut Res; 25:7287-98.\u003c/li\u003e\n\u003cli\u003eAneja KR (2003) Experiments in microbiology, plant pathology and biotechnology, 4th edn. New Age International, New Delhi.\u003c/li\u003e\n\u003cli\u003eArutchelvi J, Sudhakar M, Arkatkar A, Doble M, Bhaduri S et al (2008) Biodegradation of polyethylene and polypropylene. Indian J Biotechnol 7: 9-22.\u003c/li\u003e\n\u003cli\u003eBosker T, Bouwman J, Brun NR, Behrens P, Vijver, MG (2019) Microplastics accumulate on pores in seed capsule and delay germination and root growth of the terrestrial vascular plant Lepidium sativum. Chemosphere 226:774 781. doi:10.1016/j.chemosphere.2019.03.163.\u003c/li\u003e\n\u003cli\u003eFeil A, Pretz T (2020) Mechanical recycling of packaging waste. Plastic Waste and Recycling Elsevier, pp. 283\u0026ndash;319. https://doi.org/10.1016/B978-0-12-817880- 5.00011-6.\u003c/li\u003e\n\u003cli\u003eFuhs GW (1961) Der mikrobielle Abbau von Kohlenwasserstoffen. Arch Microbiol 39:374\u0026ndash;422.\u003c/li\u003e\n\u003cli\u003eHarshvardhan K, Jha B (2013) Biodegradation of low-density polyethylene by marine bacteria from pelagic waters, Arabian Sea, India. Marine Poll Bull. 77(1): 100-106.\u003c/li\u003e\n\u003cli\u003eHou. J, Xu. X, Yu. H, Xi. B, Tan. W (2021) Comparing the long-term responses of soil microbial structures and diversities to polyethylene microplastics in different aggregate fractions. Environ. Int., 149, Article 106398, 10.1016/j.envint.2021.106398.\u003c/li\u003e\n\u003cli\u003eKartikey KG, Deepa D, Deepanshu R (2016) Isolation and screening of low density polyethylene (LDPE) degrading bacterial strains from waste disposal sites. World Journal of Pharmaceutical Research 5(11): 1633-1643. \u003c/li\u003e\n\u003cli\u003eKyaw BM, Champakalakshmi R, SakharkarMK, Lim CS, Sakharkar KR (2012) Biodegradation of low density polythene (LDPE) by Pseudomonas species. Indian J Microbio doi:10.1007/s12088-012-0250-6\u003c/li\u003e\n\u003cli\u003eLi Z, Wei R, Gao M, Ren Y, Yu, Nie, K, Xu H, Liu (2020b) Biodegradation of low-density polyethylene by \u003cem\u003eMicrobulbifer hydrolyticus \u003c/em\u003eIRE-31. J. Environ. Manag. 263, 110402 https://doi.org/10.1016/j.jenvman.2020.110402.\u003c/li\u003e\n\u003cli\u003eNelson B, What can 28,000 Rubber Duckies Lost at Sea Teach Us about Our Oceans. Vol. 3. Atlanta: Mother Nature Network; 2011. p. 1.\u003c/li\u003e\n\u003cli\u003eRomani VP, Martins VG, Goddard JM (2020) Radical scavenging polyethylene films as antioxidant active packaging materials. Food Control 109, 106946. https://doi. org/10.1016/j.foodcont.2019.106946.\u003c/li\u003e\n\u003cli\u003eSangale M, Shahnawaz M, Ade A (2012) A review on biodegradation of polythene: the microbial approach. http://dx.doi.org/10.4172/2155-6199.1000164.\u003c/li\u003e\n\u003cli\u003eSarker M (2011) Converting waste plastic to hydrocarbon fuel materials. Energy Engineering 108(2):35\u0026ndash;43. doi:10.1080/01998595.2011.10389018.\u003c/li\u003e\n\u003cli\u003eShah AA, Hasan F, Hameed A, Ahmed S (2008) Biological degradation of plastics: a comprehensive review. Biotechnol Adv 26:246\u0026ndash;265. doi:10.1016/j.biotechadv.2007.12.005.\u003c/li\u003e\n\u003cli\u003eShahnawaz M, Manisha KS, Avinash B (2016) Bacteria-based polythene degradation products: GC-MS analysis and toxicity testing. International Research Journal of Environment Sciences\u003cem\u003e \u003c/em\u003e4(11): 58-61.\u003c/li\u003e\n\u003cli\u003eSharma A, Sharma A (2004) Degradation assessment of low density polythene (LDP) and polythene (PP) by an indigenous isolate of Pseudomonas stutzeri. J Sci Ind Res 63:293\u0026ndash;296.\u003c/li\u003e\n\u003cli\u003eSmith WM (1964) Manufacture of plastic, Volume 1. Technology and Engineering, Reinhold Pub. Corp, USA. \u003c/li\u003e\n\u003cli\u003eStarnecker A, Menner M (1996) Assessment of biodegradability of plastics under stimulated composting conditions in a laboratory test system. International Biodeterioration \u0026amp; Biodegradation\u003cem\u003e \u003c/em\u003e37(1-2): 85-92. \u003c/li\u003e\n\u003cli\u003eUsha R, Sangeetha T, Palaniswamy M (2011) Screening of Polyethylene Degrading Microorganisms from Garbage Soil. Libyan Agricultural Research Center Journal International\u003cem\u003e \u003c/em\u003e2(4): 200-204.\u003c/li\u003e\n\u003cli\u003eVijaya C, Reddy RM (2008) Impact of soil composting using municipal solid waste on biodegradation of plastics. Indian J Biotechnol 7:235\u0026ndash;239.\u003c/li\u003e\n\u003cli\u003eYuan J, Ma J, Sun Y, Zhou T, Zhao Y, and Yu F (2020) Microbial degradation and other environmental aspects of microplastics/plastics. Sci. Total Environ. 715:136968. doi: 10.1016/j.scitotenv.2020.136968\u003c/li\u003e\n\u003cli\u003eZheng Y, Yanful EK, Bassi AS (2005) A review of plastic waste biodegradation. Crit Rev Biotechnol; 25:243-50.\u003c/li\u003e\n\u003cli\u003eZhuang Yao, Hyeon Jeong Seong, Yu-Sin Jang (2022) Environmental toxicity and decompsition of polyethylene. Ecotoxicology and Environmental Safety 242 (2022) 113933. https://doi.org/10.1016/j.ecoenv.2022.113933\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Low density polyethylene, Plastic waste, Biodegradation, Synthetic medium","lastPublishedDoi":"10.21203/rs.3.rs-3224250/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3224250/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePlastics are non-biodegradable, strong, durable, moisture resistant, light weight polymers of carbon along with hydrogen, nitrogen, sulphur, and other organic and inorganic elements and are manufactured from fossil fuel which is a non-renewable source. Low density polyethylene is the most commonly occurring non-biodegradable waste material which constitutes approximately 60% of the total plastic production. In the present study, an attempt has been made to isolate, screen, and characterize the most efficient polyethylene degrading bacteria by using partially degraded polyethylene samples with adhered soil collected from two municipal waste dumping grounds of Jammu region. A total of 62 bacterial isolates were obtained from different waste disposal sites were screened on synthetic Medium. Low density polyethylene powder was used as the sole carbon source in synthetic medium. The biodegradation activity of the isolates was investigated based on the percent weight loss and percent loss in tensile strength of the polyethylene. Maximum percent weight loss (%WL; 22.66) was recorded with MB57 after 2 months of shaking at room temperature. Maximum percent loss in tensile strength (% loss in TS; 74.35) was documented MB57. Further, the level of degradation was confirmed by scanning electron microscopic (SEM) analysis. In SEM analysis, scions/ crakes were found on the surface of the degraded polyethylene.\u003c/p\u003e","manuscriptTitle":"Biodegradation of municipal plastic wastes collected from solid waste landfills of Jammu, India","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-08-07 16:14:12","doi":"10.21203/rs.3.rs-3224250/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7717691d-f109-4d27-8c56-dbdd0e4b2515","owner":[],"postedDate":"August 7th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2023-09-28T00:14:07+00:00","versionOfRecord":[],"versionCreatedAt":"2023-08-07 16:14:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3224250","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3224250","identity":"rs-3224250","version":["v1"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}