SRA

The significance of different carbon (C) cycling pathways involved in the turnover of recalcitrant carbon under various redox conditions is still a topic of debate, and in fact, unknown C cycling pathways are still being discovered. Redox transitions exist along gradients of increasingly recalcitrant C in many environments and metagenomic sequencing coupled with hydrogeochemistry could determine redox control on microbial processes at the genotypic/ecological level. The proposed study will identify: (i) the metabolic capacities of recalcitrant organic carbon utilization of coal-associated microbial communities, and (ii) the microbial assemblages and associated subsurface carbon processing and methane production from recalcitrant coal samples collected along a vertical redox gradient. This fundamental knowledge is necessary to understand the microbial processes governing subsurface carbon turnover in relationship to biogenic CH4 and helps identify unknown pathways that link terrestrial subsurface C cycling with CO2 and CH4. The metagenomic data will be placed into the context of a larger dataset consisting of hydrological, geochemical, and SSU rRNA gene amplicon sequencing (with stable isotope probing) metadata. PI: Matthew W. Fields, Montana State University.