Important Role of Fungi in the Production of Secondary Biogenic Coalbed Methane in China's Southern Qinshui Basin

摘要

It is commonly accepted that biogenic coalbed methane (CBM) is formed by anaerobic bacteria and methanogens via coal biodegradation. While the syntrophic cooperation between fungi and methanogens has been well-established in the production of methane from rumen, little is known about the role that fungi play in the formation of biogenic CBM. Miseq sequencing and mcrA gene library were employed to investigate the fungal, archaeal, and bacterial communities in produced water from Qinshui Basin, a major site for CBM exploitation in China. The syntrophic relationship between fungi degrading coal and methanogens producing methane was also investigated. A diversity of fungal communities was found in produced water from different coal seams with the dominance of Ascomycota and Basidiomycota. Hydrogenotrophic methanogens, Methanobacterium, were also found to be predominant in produced water as revealed by Miseq sequencing and mcrA gene library analysis. Bacterial communities with potential to degrade coal were also recovered in produced water. Large yields of methane were produced in incubations with produced water and coal. Incubations that included antibiotics achieved 62.24% to 97.53% of the methane production as compared to the incubations without antibiotics. These results confirmed that most of the biogenic gas was produced by hydrogenotrophic methanogens and demonstrated the important role that fungi play in the biodegradation of coal.