Analysis of microbial community in a full-scale biogas digester of cold region using high-throughput sequencing technology

To realize the stable and efficient operation of biogas digester in cold region, a combined regulation technique of microbial community should be established. The microbial community in the largest full-scale digester of Hailin Farm was investigated using 454 pyrosequencing technology and PCR-DGGE. The massively parallel sequencing technology was used to measure bacterial diversity of biogas slurry during a stable operation. A total of 1297 sequences were obtained, and the dominant bacteria were Firmicutes, Bacteroidetes and Proteobacteria, which accounted for 46.39%, 21.41% and 18.98%, respectively. At genus level (the relative abundances>5.0%), Proteiniphilum, Spirochaeta and Wolinella were the abundant taxa. The diversities of methanogen were analyzed using PCR-DGGE, and the detected archaea were Methanocorpusculum sp., Methanosaeta sp., Methanobacterium sp. and Methanosarcina sp.. Notably, the methane produced by acetoclastic methanogens, and dominant fermentative bacteria during the hydrolysis and acidogenesis were detected form animal digestive system.