Analysis of microbial communities in the oil reservoir subjected to CO₂-flooding by using functional genes as molecular biomarkers for microbial CO₂ sequestration

TY - JOUR

T1 - Analysis of microbial communities in the oil reservoir subjected to CO2-flooding by using functional genes as molecular biomarkers for microbial CO2 sequestration

AU - Liu, Jin Feng

AU - Sun, Xiao Bo

AU - Yang, Guang Chao

AU - Mbadinga, Serge M.

AU - Gu, Ji Dong

AU - Mu, Bo Zhong

N1 - Publisher Copyright: © 2015 Liu, Sun, Yang, Mbadinga, Gu and Mu.

PY - 2015

Y1 - 2015

N2 - Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs.

AB - Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs.

KW - Bioconversion

KW - CO fixation

KW - Functional genes

KW - Methane

KW - Microbial communities

KW - Oil reservoir

UR - http://www.scopus.com/inward/record.url?scp=84927551631&partnerID=8YFLogxK

U2 - 10.3389/fmicb.2015.00236

DO - 10.3389/fmicb.2015.00236

M3 - 文章

AN - SCOPUS:84927551631

SN - 1664-302X

VL - 6

JO - Frontiers in Microbiology

JF - Frontiers in Microbiology

IS - MAR

M1 - 236

ER -