Unravelling the microbial community structure and function of coal-bed methane producing formation water of Jharia coal mines using metagenomics approach

Abstract

India has a significant coal reserve appropriate for the coal bed methane development. The present study encompasses metagenomics-based functional and taxonomic biodiversity in formation water samples collected from coal bed methane well located at the Jharia coal bed basin. The whole metagenome sequencing obtained via 454 pyrosequencing revealed occurrence of several bacterial and archaeal microbial communities. The preponderance of Proteobacteria specified probable aromatic hydrocarbon degradation linked to coal organics. The sequences affiliation to most abundant genera of the phylum Euryarchaeota could be related to Methanobacterium, Methanobrevibacter and Methanothermobacter. Prevalence of methanogens growing under the mesophilic conditions indicated the possibility of the occurrence of mesophilic, hydrogenotrophic methanogenesis. One of the most important findings that the coal bed methane (CBM) microbiome was colonized by anaerobic as well as aerobic bacteria; thereby suggesting that the microbial community at the subsurface might have available oxygen at a low concentration. The study reports an enhanced methane production of 1.66 and 1.51 times higher in the ratio of 1:2 than 1:1 and 1:3 for bacterial: methanogenic inoculum respectively.