sludge anaerobic digestion microbial community Raw sequence reads
The widespread use of bisphenol A (BPA) has resulted in the emergence of new pollutants in various environmental compartments, particularly concentrated in sewage sludge from wastewater treatment plants. This study investigated the effects of high BPA concentration on sludge anaerobic digestion, focusing specifically on the interaction of microbial communities and their metabolic responses. Results showed that BPA can improve the conversion of organic substances during digestion, leading to notable reductions in soluble COD, protein, and polysaccharides. The study also revealed that BPA positively influenced the hydrolysis-acidogenesis process, leading to 17% higher concentrations of volatile fatty acids (VFAs) and a subsequent 5% rise in cumulative biogas production. Regarding the critical microbial metabolic potentials, increasing BPA concentrations showed a pattern of "inhibition at low concentrations and promotion at high concentrations" in hydrolysis and acidogenesis related gene abundances. Diverse methane metabolism was observed and exhibited alterations under BPA exposure. The presence of BPA impacted both the diversity and composition of microbial populations. Bacterial diversity increased under BPA exposure, promoting organic matter degradation and higher biogas production. BPA-treated groups were dominated by Bacteroidetes, Proteobacteria, Firmicutes, and Chloroflexi, which exhibited varying changes in abundance among different BPA treatments. Changes of specific genera Sedimentibacter, Fervikobacterium, Blvii28, and Coprothermobactedasdr in response to BPA, affecting hydrolysis and acetogenesis. Archaeal diversity declined while the acetoclastic methanogen Methanospirillum thrived under BPA exposure. Moreover, BPA exposure enabled microorganisms to form structured community interaction networks and boost their metabolic activities during anaerobic digestion. The study also observed the enrichment of BPA biodegradation pathways at high BPA concentrations, which could interact and overlap to ensure efficient BPA degradation. In summary, the study provides insights into the digestion performance and interactions of microbial communities to BPA stress and sheds light on the potential fate of BPA during anaerobic digestion.