Pyrosequencing reveals the dominance of methylotrophic methanogenesis in a coal bed methane reservoir associated with Eastern Ordos Basin in China

Abstract

a b s t r a c t a r t i c l e i n f oIt is generally believed that biogenic coal bed methane (CBM) is an end product of coal biodegradation by methanogenic archaea and syntrophic bacteria. In this work, the archaeal and bacterial communities of CBM reservoir associated with Ordos Basin in China were investigated using 454 pyrosequencing. Sampling produced water, coal and rock in the reservoir, a total of 46,598 sequence reads were obtained. All archaea were methanogens with the genus Methanolobus predominating. The genus consisted of 81.18% of pyrosequencing reads in water sample and > 99% in coal and rock samples. Although the phylum Proteobacteria was the main component of all samples, bacterial communities in coal and rock samples were similar at the genus level, which were distinctly separated with water sample. The results strongly suggested that methylotrophic methanogenesis governed the biogenic CBM formation. The separation of microbial communities between water and coal, rock samples should be considered when investigating the process of coal biodegradation and the generation of new biogenic CBM.

Microbial Methane Potential for the South Sumatra Basin Coal: Formation Water Screening and Coal Substrate Bioavailability

“…A summary of the results obtained is shown in Figure 4a. The microbial communities identified in SSB formation water were similar to those found previously in other CBM reservoirs [3,5,8,[30][31][32][33]. However, it is noteworthy that although broad similarities in the structure of the microbial communities exist, each tested water has a unique community structure that differs with respect to its primary community members and their dominance (Figure 4a).…”

Spatial Pattern of Bacterial Community Diversity Formed in Different Groundwater Field Corresponding to Electron Donors and Acceptors Distributions at a Petroleum-Contaminated Site

“…Samples MW3 and MW17 were associated with high Fe 2+ and low SO 4 2− , which indicated that the electron acceptors Fe 3+ and SO 4 2− had been consumed, these two samples probably were in the methanogenesis stage. These two samples had the highest abundances of Hydrogenophaga, which is always closely related with methanogenic archaea [47,48]. Other studies have suggested that Hydrogenophaga might have catalyzed hydrogen production or perhaps was an oxygen scavenger, and that it created the strictly anoxic conditions essential for the methanogenic archaea [49].…”

Identifying the core bacterial microbiome of hydrocarbon degradation and a shift of dominant methanogenesis pathways in the oil and aqueous phases of petroleum reservoirs of different temperatures from China

“…Numerous studies based on in situ or in enrichment incubation microcosms on the aqueous phase of reservoir fluids indicate that syntrophic acetate oxidation associated with hydrogenotrophic methanogenesis is the major hydrocarbon degradation pathway (Wang et al, 2012;Mayumi et al, 2011;Lee et al, 2015;Mbadinga et al, 2012;Gray et al, 2011). The dominance of hydrogenotrophic methanogenesis in subsurface ecosystems could result from the external hydrogen originating from maturation of organic matter and/or mineral hydrolysis (Head et al, 2003) and the synergistic effect, in association with acetate oxidizers, whereby acetate was firstly oxidized to H 2 and CO 2 is then utilized by methanogenesis (Liu and Whitman, 2008). Additionally, a stable isotope labeling experiment on oil-degrading microcosms showed that despite the coexistence of acetoclastic methanogenesis and acetate syntrophic oxidization in the initial state, the latter process prevailed over the former one when introducing a low acetate concentration initially (Gray et al, 2011).…”