基于高通量测序的寒地沼气池微生物群落解析

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

为实现寒地沼气发酵系统高效、稳定运行,应建立基于沼气发酵微生物群落的复合调控策略.本研究耦合454高通量测序和PCR-DGGE分析方法,对北方规模最大的海林农场沼气池内细菌及产甲烷古菌群落结构进行解析.取沼气池稳定运行期沼液样品,分析系统内微生物群落多样性.结果显示,共获得1 297条高质量微生物序列,在属和种的分类水平上,至少存在581个细菌属和666个细菌种.优势菌群有Firmicutes、Bacteroidetes及Proteobacteria,相对丰度分别为46.39%、21.41%和18.98%.优势属(相对丰度>5.0%)包括Proteiniphilum、Spirochaeta和Wolinella.DGGE分析结果表明,产甲烷古菌包括Methanocorpusculum sp.、Methanosaeta sp.、Methanobacterium sp.及Methanosarcina sp..,表明沼气池的产甲烷途径以乙酸代谢类型为主,水解、酸化过程主要由来自动物消化系统内的细菌完成.

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 WolineUa 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.