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

Abstract

Tequila vinasse, a by-product of agave fermentation, is a wastewater characterized by its dark coloration and complex composition, including water, alcohols, sugars, phenolic compounds, and proteins, among other constituents. Its elevated chemical oxygen demand (COD) and acidic pH levels render it hazardous to soil, plants, and aquatic organisms, requiring the development of efficient treatment strategies or proper disposal methods. It is worth noting that vinasse contains bioactive compounds with biotechnological potential. In this study, tequila vinasse at different concentrations (100%, 70%, and 50%) was subjected to a 10-day bioremediation process using the ligninolytic fungus Trametes sanguineus. The treatment resulted in reductions in color (48-76%), phenolic content (60-68%), and COD (22-36%) across all conditions. The highest laccase activity was observed in the 50% vinasse concentration, reaching 1,779 U/L on the fifth day of incubation. Subsequently, the detoxified vinasse was assessed for its impact on seed germination and seedling development. After fungal removal, the supernatant was directly applied to tomato (Solanum lycopersicum) and lettuce (Lactuca sativa) seeds. Germination rates exceeded 60% in both plant species, whereas untreated vinasse completely inhibited germination. Furthermore, seedling growth assays demonstrated that the treated vinasse supported root elongation in tomato and lettuce, exhibiting growth patterns comparable to those observed in the control. The high tolerance of T. sanguineus to tequila vinasse underscores its potential as a sustainable bioremediation strategy for vinasse detoxification.