Microbial diversity, distribution patterns and syntrophic correlation in anaerobic processes for energy production

Anaerobic process is widely used for treating high-strength wastewater. The degradation of organic matter and the effective methanogenesis require the cooperation of various kinds of bacteria and archaea. Therefore, uUnderstanding the ecological patterns of these microorganisms and effect of environmental factors on microbial community are important to manage the performance of anaerobic process. High-throughput sequencing of 16S rRNA genes was used to investigate Mmicrobial communities of the 12 anaerobic sludge samples acclimated under different environmental conditions were investigated. Genera detected from these anaerobic sludge samples generally presented three kinds of distribution patterns: frequently detected with high abundance, frequently detected with low abundance and occasionally detected with permanently low abundance. The type of organic substrates was one of the most important environmental factors affecting microbial community. Dye wastewater and the supplement of conductive materials were also found to shape the microbial community variously. Syntrophic bacteria and methanogens widely existed but were rare in many anaerobic samples, implying the potential complicated interactions within the anaerobic community. Strong correlations between syntrophic partners suggested that rare genera might be also responsible for syntrophic methanogenesis.