Microbial diversity and biogenic methane potential of a thermogenic-gas coal mine

• Published in: International journal of coal geology 2014-11, Vol.134-135, p.96-107
• Main Authors: Wei, Min, Yu, Zhisheng, Jiang, Zheng, Zhang, Hongxun
• Format: Article
• Language: English
• Subjects: 454 pyrosequencing; Acetates; Acetotrophic methanogen; Actinobacteria; Bacteria; Biogenic methane; Clostridiales; Coal; Coal mines; Communities; Earth sciences; Earth, ocean, space; Enrichment; Exact sciences and technology; Firmicutes; Isotope geochemistry; Isotope geochemistry. Geochronology; Methane; Methanosarcina; Microorganisms; Proteobacteria; Real-time PCR; Sedimentary rocks
• ISSN: 0166-5162; 1872-7840
• DOI: 10.1016/j.coal.2014.09.008

The microbial communities and biogenic methane potential of a gas coal mine were investigated by cultivation-independent and cultivation-dependent approaches. Stable carbon isotopic analysis indicated that in situ methane in the coal mine was dominantly of a thermogenic origin. However, a high level of diversity of bacteria and methanogens that were present in the coal mine was revealed by 454 pyrosequencing, and included various fermentative bacteria in the phyla of Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria, and acetotrophic, hydrogenotrophic, and methylotrophic methanogens. Methane was produced in enrichments of mine water samples supplemented with acetate under laboratory conditions. The microbial flora obtained from the enrichments could stimulate methane formation from coal samples. 16S rRNA gene clone library analysis indicated that the microbial community from coal cultivation samples supplemented with the enriched microbial consortium was dominated by the anaerobic fermentative Clostridiales and facultative acetoclastic Methanosarcina. This study suggests that the biogenic methane potential in the thermogenic-gas coal mine could be stimulated by the indigenous microorganisms. [Display omitted] •A high diversity of methanoges and fermentayive bacteria existed in coal seam.•Acetotrophic methanogenesis was predominant in coal seam.•Bioconversion from coal to methane could be realized by enriched native microbial consortia.