Microbial community of rural household biogas digesters in Qinghai by PCR-DGGE

The microbial community composition in rural household biogas digesters of Qinghai was investigated with polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE) technology. The results showed that the diversity of bacteria and archaea were rich, and the shift of microbial community was obvious in digesters. The bacterial communities in four biogas digesters were classified into five phyla, Bacteroidetes, Firmicutes and Proteobacteria were identified to be dominant. At genome level, belonging to twenty-four communities, Petrimonas, Pseudomona, Tissierella and Clostridium were the abundant taxa. Meanwhile, the species of archaeal community were calssified as Methanobrevibacter, Methanogenium, Methanoculleus and Thermofilum, and the first two classes were dominant in the digesters. Notably, the methane produced by hydrogen nutrition methanogens, and the dominant fermentative bacteria during the hydrolysis and acidogenesis were detected from animal digestive system.