典型沼气发酵生态系统微生物多样性的变化研究

Changes of Microbial Diversity in a Typical Biogas Fermentation Ecosystem

为揭示云南亚热带地区稳定运行的水压式沼气池中微生物多样性的变化,从2019年2-6月每月采集池内微生物样品,采用16S rDNA测序技术对云南亚热带代表性气候区的100 m^(3)的水压式沼气池中微生物多样性进行研究。结果表明:沼气发酵微生物群落结构的物种组成可能随着该地区的气候变化而发生变化,但总体变化不大;在目水平上的优势菌群有梭菌目(Clostridiales,占33.80%)、甲烷八叠球菌目(Methanosarcinales,占27.70%)、拟杆菌目(Bacteroidales,占18.60%)、厌氧绳菌目(Anaerolineales,占5.38%);产甲烷菌主要由甲烷丝菌属(Methanothrix,占42.00%)、甲烷螺菌属(Methanospirillum,占1.38%)和甲烷八叠球菌属(Methanosarcina,占0.88%)占主导。在云南亚热带代表性气候区水压式沼气池稳定运行的过程中,随时间变化微生物多样性及结构组成差异性不明显,产甲烷菌主要以乙酸型产甲烷菌为主导,甲烷转换途径随着时间变化也未发生显著性变化,同时RDA分析(Redundancy analysis)表明池内温度、进料量均会影响产甲烷菌的生长繁殖,最终影响日产甲烷量。

To reveal the changes of microbial communities in hydraulic biogas digesters that are operated stably in the subtropical region of Yunnan,monthly microbial samples from February to June in 2019 were collected,using the technology of 16S rDNA sequencing,to study the microbial diversity from a 100 m^(3) hydraulic biogas digester in a representative subtropical climate zone of Yunnan.The results showed the species composition of the microbial community from the biogas digester may change with the climate in the region,but with slight overall change;the dominant flora at the order level were Clostridiale(33.80%),Methanosarcinales(27.70%),Bacteroidales(18.60%)and Anaerolineales(5.38%);the methanogens were mainly dominated by Methanothrix(42.00%),Methanospirillum(1.38%)and Methanosarcina(0.88%).During the stable operation of the hydraulic biogas digester in the representative subtropical climate zone of Yunnan,it is found that the microbial diversity and structural composition do not differ significantly over time,the methanogens were mainly dominated by acetic methanogens,and the conversion pathway of methane had not changed significantly over time.Meanwhile,the RDA analysis showed that the temperature in the biogas digester and feeding quantity would affect the growth and reproduction of methanogens,and eventually affect the daily methane production.