Long-term succession in a coal seam microbiome during in situ biostimulation of coalbed-methane generation

Abstract

Despite the significance of biogenic methane generation in coal beds, there has never been a systematic long-term evaluation of the ecological response to biostimulation for enhanced methanogenesis in situ . Biostimulation tests in a gas-free coal seam were analysed over 1.5 years encompassing methane production, cell abundance, planktonic and surface associated community composition and chemical parameters of the coal formation water. Evidence is presented that sulfate reducing bacteria are energy limited whilst methanogenic archaea are nutrient limited. Methane production was highest in a nutrient amended well after an oxic preincubation phase to enhance coal biofragmentation (calcium peroxide amendment). Compound-specific isotope analyses indicated the predominance of acetoclastic methanogenesis. Acetoclastic methanogenic archaea of the Methanosaeta and Methanosarcina genera increased with methane concentration. Acetate was the main precursor for methanogenesis, however more acetate was consumed than methane produced in an acetate amended well. DNA stable isotope probing showed incorporation of 13 C-labelled acetate into methanogenic archaea, Geobacter species and sulfate reducing bacteria. Community characterisation of coal surfaces confirmed that methanogenic archaea make up a substantial proportion of coal associated biofilm communities. Ultimately, methane production from a gas-free subbituminous coal seam was stimulated despite high concentrations of sulfate and sulfate-reducing bacteria in the coal formation water. These findings provide a new conceptual framework for understanding the coal reservoir biosphere.

Microbial Communities on Plastic Polymers in the Mediterranean Sea

“…Hydrocarbon-degrading Bacteria (HCB) are hence potential candidates to utilize or cometabolize these types of plastics ( Dussud et al, 2018b ; Basili et al, 2020 ; Erni-Cassola et al, 2020 ). HCB use linear, branched, or aromatic hydrocarbons as sole energy, and carbon source and are often found in oil reservoirs, oil seeps, or oil spills ( Joye et al, 2014 ), contaminated sediments ( Kimes et al, 2013 ) and coal beds ( Beckmann et al, 2019 ), but they are also found ubiquitously in the marine environment ( Yakimov et al, 2007 ; Erni-Cassola et al, 2020 ; Thompson et al, 2020 ). Although HCB are often detected on plastic ( Wright et al, 2020 ), previous investigations seldomly focus on the potential role of HCB as MPD degraders ( Erni-Cassola et al, 2020 ).…”

Bioconversion of coal to methane by microbial communities from soil and from an opencast mine in the Xilingol grassland of northeast China

“…The red square indicates the corresponding taxa found in this study had 98% or higher identity to the sequences in CSMB reference set and co-occurred across a range of published studies. a [80], b [45], c [22], d [14], e [81], f [15], g [82], h [11], i [83], j [13], k [84], l [63]…”

Genomic and phenotypic insights point to diverse ecological strategies by facultative anaerobes obtained from subsurface coal seams

“…One of the highly abundant OTUs (Operational Taxonomic Unit) observed in this 16S rRNA amplicon sequence based study was taxonomically identified as a pseudomonad (OTU_9), and its presence during early colonisation suggested it may play some role in degrading organic matter in coal. Interestingly, Pseudomonas species have been previously identified from almost all surveys of coal seams conducted to date 6,12–25 and pseudomonads isolated from coals in the past have been reported for the production of biosurfactants 26 and lignin degradation phenotypes 27 . Additionally, a previous study has noted the prevalence of seemingly aerobic taxa and metabolisms in deep anoxic hydrocarbon environments 28 .…”