Microbial community evolution, interaction, and functional genes prediction during anaerobic digestion in the presence of refractory organics

Anaerobic digestion (AD) effectively recovers resources and reduces organic waste, but microbial activity can be inhibited by refractory compounds. The degradation efficiency in refractory wastewaters depends on the inoculum resistance to toxicity. In this study, we analyzed the relationship between substrate and dominant microbial communities by the domestication of acetate, glucose, and wood vinegar. The complex components of wood vinegar developed a microbial community with relatively balanced abundance, which evidenced the co-metabolism of synergetic species. The increased abundance of JGI-0000079-D21, Aminicenantales, Bacteroidetes-vadinHA17, and Mesotoga was associated with the degradation of phenols and N-heterocyclic compounds. The metabolism of acetotrophic methanogens was significantly higher than that of hydrogenotrophic methanogens in the presence of acetate. The species and abundance of functional genes were stabilized by complex components, whereas the reverse was true for single substrates. Our findings can improve the quality of the inoculants used in the biological treatments of refractory wastewater. [Display omitted] •The microbial function and co-metabolism were revealed in continuous domestication.•SBR1031, JGI-0000079-D21, Aminicenantales, and Mesotoga synergistically detoxified.•Clostridium, Ethanoligenens, and Caldisericum had special capabilities for glucose.•Glucose contributed to hydrogenotrophics more than acetotrophics, acetate reversed.•Phenols and N-compounds stabilized the diversity and abundance of functional genes.