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

Abstract

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.

The effect of NaOH pretreatment on coal structure and biomethane production

“…The anaerobic medium included 3 mL basic medium, 0.15 mL trace metals solution, 0.15 mL vitamin solution, 0.6 mL cysteine (15%)-Na 2 S (15%), and 23.1 mL sterile water. The composition and content of the basic medium, trace mineral solution, and vitamin solution were prepared according to our previous work [31]. The cultivations without coal were setup as negative control.…”

Biogeochemistry and the associated redox signature of co-produced water from coalbed methane wells in the Shizhuangnan block in the southern Qinshui Basin, China

“…3 coal seam from the lower Permian Shanxi formation and the No. 15 coal seam from the upper Carboniferous Taiyuan formation are the major minable coal-bearing formations, with thick continuous lateral coal-bearing seams and relatively stable distributions (Guo et al., 2017).…”

Microbial Communities Involved in Methane Production from Coal Treated by Potassium Permanganate

“…Coal was first pulverized and washed using a 0.05M sterile phosphate buffer (pH 7.4) containing 0.2% Tween 80 as described previously [21,22] to elute the microorganisms attached to the surface of coal and eliminate any interference of heavy metals which might reduce the efficiency of DNA extraction. After washing, the solutions were filtered through a 0.22-μm membrane filter (Whatman, Japan).…”

“…The protocol of PCR, sequencing and data analysis were performed as described previously [21,22]. Briefly, the 16S r RNA variable region 4 (V4) were amplified using the universal primer sets 515F/806R (GTGCCAGCMGCCGCGGTAA/GGACTACHVGGGTWTCTAAT) which have been used for Illumina-based surveys to amplified bacterial and archaeal 16S r RNA genes [22].…”