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Microbial potential for carbon and nutrient cycling in a geogenic supercritical carbon dioxide reservoir
Author(s) -
Freedman Adam J.E.,
Tan BoonFei,
Thompson Janelle R.
Publication year - 2017
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13706
Subject(s) - biogeochemical cycle , metagenomics , carbon cycle , biology , environmental chemistry , microbial population biology , nitrogen cycle , extremophile , ecosystem , phototroph , nutrient cycle , carbon fixation , biogeochemistry , carbon dioxide , microorganism , ecology , nitrogen , chemistry , botany , bacteria , photosynthesis , biochemistry , genetics , organic chemistry , gene
Summary Microorganisms catalyze carbon cycling and biogeochemical reactions in the deep subsurface and thus may be expected to influence the fate of injected supercritical (sc) CO 2 following geological carbon sequestration (GCS). We hypothesized that natural subsurface scCO 2 reservoirs, which serve as analogs for the long‐term fate of sequestered scCO 2 , harbor a ‘deep carbonated biosphere’ with carbon cycling potential. We sampled subsurface fluids from scCO 2 ‐water separators at a natural scCO 2 reservoir at McElmo Dome, Colorado for analysis of 16S rRNA gene diversity and metagenome content. Sequence annotations indicated dominance of Sulfurospirillum , Rhizobium, Desulfovibrio and four members of the Clostridiales family. Genomes extracted from metagenomes using homology and compositional approaches revealed diverse mechanisms for growth and nutrient cycling, including pathways for CO 2 and N 2 fixation, anaerobic respiration, sulfur oxidation, fermentation and potential for metabolic syntrophy. Differences in biogeochemical potential between two production well communities were consistent with differences in fluid chemical profiles, suggesting a potential link between microbial activity and geochemistry. The existence of a microbial ecosystem associated with the McElmo Dome scCO 2 reservoir indicates that potential impacts of the deep biosphere on CO 2 fate and transport should be taken into consideration as a component of GCS planning and modelling.