Abstract
Microbial coal-bed methane is an important economic resource and source of a potent greenhouse gas, but controls on its formation are poorly understood. To test whether the microbial degradability of coal limits microbial methane, we monitored methoxyl group demethylation-a reaction that feeds methanogenesis-in a global sample suite ranging in maturity from wood to bituminous coal. Carbon isotopic compositions of residual methoxyl groups were inconsistent with a thermal reaction, instead implying a substrate-limited biologic process. This suggests that deep biosphere communities participated in transforming plant matter to coal on geologic time scales and that methoxyl abundance influences coal-bed methane yield. Carbon isotopic enrichments resulting from microbial methylotrophy also explain an enigmatic offset in the carbon-13 content of microbial methane from coals and conventional hydrocarbon deposits.
Original language | English (US) |
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Pages (from-to) | 894-897 |
Number of pages | 4 |
Journal | Science |
Volume | 374 |
Issue number | 6569 |
DOIs | |
State | Published - Nov 12 2021 |
All Science Journal Classification (ASJC) codes
- General