title: Viability and adaptation potential of indigenous microorganisms from natural gas field fluids in high pressure incubations with supercritical CO2.
abstract: Carbon Capture and Storage (CCS) is currently under debate as large-scale solution to globally reduce emissions of the greenhouse gas CO2. Depleted gas or oil reservoirs and saline aquifers are considered as suitable reservoirs providing sufficient storage capacity. We investigated the influence of high CO2 concentrations on the indigenous bacterial population in the saline formation fluids of a natural gas field. Bacterial community changes were closely examined at elevated CO2 concentrations under near in situ pressures and temperatures. Conditions in the high pressure reactor systems simulated reservoir fluids i) close to the CO2 injection point, i.e. saturated with CO2, and ii) at the outer boundaries of the CO2 dissolution gradient. During the incubations with CO2, total cell numbers remained relatively stable, but no microbial sulfate reduction activity was detected. After CO2 release and subsequent transfer of the fluids, an actively sulfate-respiring community was re-established. The predominance of spore-forming Clostridiales provided evidence for the resilience of this taxon against the bactericidal effects of supercritical (sc)CO2. To ensure the long-term safety and injectivity, the viability of fermentative and sulfate-reducing bacteria has to be considered in the selection, design, and operation of CCS sites.
authors: Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Lower Saxony, Germany.
authors: Janin
authors: J
authors: Frerichs
authors: Jana
authors: J
authors: Rakoczy
authors: Christian
authors: C
authors: Ostertag-Henning
authors: Martin
authors: M
authors: Krüger
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D002245:Carbon Dioxide / Q000494:pharmacology*; D015169:Colony Count, Microbial; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D006874:Hydrostatic Pressure; D050296:Microbial Viability / Q000187:drug effects*; D059206:Natural Gas / Q000382:microbiology*; D061329:Oil and Gas Fields / Q000382:microbiology*; D010084:Oxidation-Reduction / Q000187:drug effects; D013431:Sulfates / Q000378:metabolism
chemical_list: D059206:Natural Gas; D013431:Sulfates; D002245:Carbon Dioxide