Detoxification of tequila vinasse by Trametes sanguineus: a biotechnological approach to laccase production and water reuse in seedling growth

Tequila vinasse, a by-product generated during agave fermentation, is a wastewater characterized by its dark color and composition, which includes water, alcohol, sugars, phenolic compounds, proteins, among others. Its high chemical oxygen demand (COD) and pH levels classify it as hazardous to the soil, plants, and aquatic organisms, requiring the development of treatment strategies or proper disposal methods. It is worth noting that vinasse contains numerous compounds that can be recovered and valorized. In this study, different concentrations of tequila vinasse (100%, 70%, and 50%) were subjected to a 10-day treatment with Trametes sanguineus . Significant reductions in color, phenolic content, and COD were observed across all conditions, with approximately 70% decolorization and 60% reduction in phenolic content achieved. Among the different conditions tested, the 50% concentration exhibited the highest laccase production, reaching approximately 1,779 U/L on the 5th day of cultivation, while laccases were also detected in the other conditions. Subsequently, the potential of the treated vinasse for germination and seedling growth was assessed. Trametes sanguineus was removed from the vinasse, and the resulting supernatant was applied directly to the seeds. Lettuce and tomato seeds were employed in these assays, both of which demonstrated seed germination rates ranging from 50–80%, respectively. Notably, vinasse without T. sanguineus treatment did not exhibit any germination. Additionally, seedling growth assays were conducted, revealing that the treated vinasse supported the growth of tomato and lettuce plants, with root-related features comparable to the control. Valorization of agroindustrial waste presents a viable approach for obtaining value-added products.