Methanogenic archaea in subsurface coal seams are biogeographically distinct: an analysis of metagenomically‐derived mcrA sequences

Abstract

Summary The production of methane as an end‐product of organic matter degradation in the absence of other terminal electron acceptors is common, and has often been studied in environments such as animal guts, soils and wetlands due to its potency as a greenhouse gas. To date, however, the study of the biogeographic distribution of methanogens across coal seam environments has been minimal. Here, we show that coal seams are host to a diverse range of methanogens, which are distinctive to each geological basin. Based on comparisons to close relatives from other methanogenic environments, the dominant methanogenic pathway in these basins is hydrogenotrophic, with acetoclastic being a second major pathway in the Surat Basin. Finally, mcrA and 16S rRNA gene primer biases were predominantly seen to affect the detection of Methanocellales, Methanomicrobiales and Methanosarcinales taxa in this study. Subsurface coal methanogenic community distributions and pathways presented here provide insights into important metabolites and bacterial partners for in situ coal biodegradation.

Selective trace elements significantly enhanced methane production in coal bed methane systems by stimulating microbial activity

“…To understand the effect of each TE on the activity of the methanogenic community, the levels of mcrA transcripts were quantified as proxies for methanogenesis ( 25 ). The amendment of TEs resulted in a significant increase of mcrA transcript levels compared to unamended microcosms ( P < 0.05) ( Fig.…”

Krumholzibacteriota and Deltaproteobacteria contain rare genetic potential to liberate carbon from monoaromatic compounds in subsurface coal seams

“…Conceptual model displaying ( A ) the Syntrophaceae sp., Krumholzibacteriota sp., and Syntrophorhabdus aromaticivorans within the Nance, Flowers-Goodale, and Terret coal seams of the Powder River Basin, USA, and ( B ) the Syntrophorhabdus aromaticivorans within the Bandanna Formation of the Bowen Basin, Australia. The most abundant methanogen/s (according to mcrA and 16S rRNA gene data) ( 27 ) in the metagenome of each bin has been included in the model; however, these are not necessarily the key partner methanogens for the aromatic-degrading taxa.…”

“…For further details of metagenomic sequence data sourcing, see reference 27 . Briefly, whole-genome shotgun sequences selected for use were required to (i) be from a subsurface coal seam (ii), state the coal seam or associated geological basin, (iii) have been sequenced using Illumina ( 28 ), and (iv) be available as unassembled sequence reads.…”