Anaerobic metabolic responses of sludge and mine wastewater-derived consortia to winery wastewater-related compounds
Winery wastewater contains readily biodegradable organic matter, but some of its components can inhibit anaerobic microbial activity. This study compares two enriched microbial consortia, derived from anaerobic digester sludge (ADS) and mining-process wastewater (MPW), exposed to alcohols, carboxylic acids, and phenolics. Assays were conducted in acetate–fumarate-based media containing low or high concentrations of each compound class and a combined condition containing the compounds at their highest levels. Growth, fumarate consumption, succinate production, acetate turnover, and compound consumption were monitored. Full-length 16 S rRNA gene sequencing showed that ADS was dominated by Proteus (56.9%) and Escherichia (28.6%). MPW showed a more even profile dominated by Proteus (35.8%), Wolinella (32.9%), and Escherichia (23.0%). Under control conditions, MPW showed higher growth (0.284 vs. 0.181 h−1) and succinate production rates (0.171 vs. 0.106 g L−1 h−1) than ADS. Alcohols caused little change in fumarate consumption, but high carboxylic acid concentrations reduced fumarate consumption rates to 0.115 and 0.162 g L−1 h−1 in ADS and MPW, respectively. Phenolics reduced the ADS succinate production rate to 0.059 g L−1 h−1, while MPW remained near its control value (0.169 vs. 0.171 g L−1 h−1). Under combined exposure, ADS maintained fumarate consumption and increased succinate production from 0.106 to 0.157 g L−1 h−1, but MPW decreased from 0.125 to 0.092 g L−1 h−1. Both bacterial composition and the chemical conditions of exposure influenced anaerobic resilience. The combined use of taxonomic and metabolic indicators may therefore improve the selection of consortia for the biodegradation and valorization of complex agro-industrial wastewaters, including their integration into bioelectrochemical platforms.