Institute of New Energy, China University of Petroleum, Beijing, 102249, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Appl Microbiol Biotechnol. 2016 Dec;100(24):10331-10341. doi: 10.1007/s00253-016-7738-7. Epub 2016 Jul 29.
In methane-rich environments, methane-oxidizing bacteria usually occur predominantly among consortia including other types of microorganisms. In this study, artificial coal bed gas and methane gas were used to enrich mixed methanotrophic cultures from the soil of a coal mine in China, respectively. The changes in microbial community structure and function during the enrichment were examined. The microbial diversity was reduced as the enrichment proceeded, while the capacity for methane oxidation was significantly enhanced by the increased abundance of methanotrophs. The proportion of type II methanotrophs increased greatly from 7.84 % in the sampled soil to about 50 % in the enrichment cultures, due to the increase of methane concentration. After the microbial community of the cultures got stable, Methylomonas and Methylocystis became the dominant type I and type II methanotrophs, while Methylophilus was the prevailing methylotroph. The sequences affiliated with pigment-producing strains, Methylomonas rubra, Hydrogenophaga sp. AH-24, and Flavobacterium cucumis, could explain the orange appearance of the cultures. Comparing the two cultures, the multi-carbon sources in the artificial coal bed gas caused more variety of non-methanotrophic bacteria, but did not help to maintain the diversity or to increase the quantity and activity of methanotrophs. The results could help to understand the succession and interaction of microbial community in a methane-driven ecosystem.
在富含甲烷的环境中，甲烷氧化菌通常主要存在于包括其他类型微生物的共生体中。本研究分别利用人工煤层气和甲烷气从中国煤矿土壤中富集混合甲烷氧化微生物培养物，研究了富集过程中微生物群落结构和功能的变化。随着富集的进行，微生物多样性降低，而甲烷氧化能力则因甲烷氧化菌丰度的增加而显著增强。由于甲烷浓度的增加，II 型甲烷氧化菌的比例从采样土壤中的 7.84%大幅增加到富集培养物中的约 50%。当培养物中的微生物群落稳定下来后，Methylomonas 和 Methylocystis 成为主要的 I 型和 II 型甲烷氧化菌，而 Methylophilus 是主要的甲基营养菌。与产色素菌株（Methylomonas rubra、 Hydrogenophaga sp. AH-24 和 Flavobacterium cucumis）相关的序列可以解释培养物的橙色外观。比较两种培养物，人工煤层气中的多种碳源导致了更多种类的非甲烷氧化菌，但并没有有助于维持微生物多样性或增加甲烷氧化菌的数量和活性。这些结果有助于理解甲烷驱动生态系统中微生物群落的演替和相互作用。
