The microbial community study of propionate-degrading and methanogenic environment in various sources of sludge

Propionic acid is a volatile fatty acid causing system instability in anaerobic digester that inhibit methanogenic activity. Several studies reported the solution using microbial enriched culture fed by propionate to reduce the accumulation and enhance biogas production, however, microbial community of the culture is lack of information. In this study, the investigation of methanogenic propionate-degrading community were revealed in various inoculum sludges by 16S rRNA-based metagenomic approach. The microbial profiles among sludge sources were observed and reveal common community in almost samples. Methanosaeta spp., Smithella spp. and Syntrophomonas spp. dominate in propionate-associated environment contributing to elevate production of methane while hydrogenotrophic methanogens were found differently depend on organic compound in wastewater. The observed result can be purpose that butyrate-degrader incorporate during propionate-degradation and improve stability in biogas production.