Simultaneous detection of transcribed functional assA gene and the corresponding metabolites of linear alkanes (C₄, C₅, and C₇) in production water of a low-temperature oil reservoir

TY - JOUR

T1 - Simultaneous detection of transcribed functional assA gene and the corresponding metabolites of linear alkanes (C4, C5, and C7) in production water of a low-temperature oil reservoir

AU - Liu, Jin Feng

AU - Lu, Yu Wei

AU - Zhou, Lei

AU - Li, Wei

AU - Hou, Zhao Wei

AU - Yang, Shi Zhong

AU - Wu, Xiao Lin

AU - Gu, Ji Dong

AU - Mu, Bo Zhong

N1 - Publisher Copyright: © 2020 Elsevier B.V.

PY - 2020/12/1

Y1 - 2020/12/1

N2 - Methanogenic hydrocarbon degradation is an important biogeochemical process in oil reservoirs; however, genomic DNA-based analysis of microorganisms and metabolite detection are not conclusive for identification of the ongoing nature of this bioprocess. In this study, a suite of analyses, involving the study of microbial community and selective gene quantification of both genomic DNA and RNA together with signature metabolites, were performed to comprehensively advance the understanding of the methanogenic biodegradation of hydrocarbons in a low-temperature oilfield. The fumarate addition products for alkanes—C4, C5, and C7-alkylsuccinates—and transcribed assA and mcrA genes were simultaneously detected in the production water sample, providing robust and convincing evidence for both the initial activation of n-alkanes and methane metabolism in this oilfield. The clone library of assA gene transcripts showed that Smithella was active and most likely responsible for the addition of fumarate to n-alkanes, whereas Methanoculleus and Methanothrix were the dominant and active methane-producers via CO2 reduction and acetoclastic pathways, respectively. Additionally, qPCR results of assA and mcrA genes and their transcribed gene copy numbers revealed a roughly similar transcriptional activity in both n-alkanes-degraders and methane producers, implying that they were the major participants in the methanogenic degradation of n-alkanes in this oilfield. To the best of our knowledge, this is the first report presenting sufficient speculation, through detection of signature intermediates, corresponding gene quantification at transcriptional levels, and microbial community analysis, of methanogenic degradation of n-alkanes in production water of an oil reservoir.

AB - Methanogenic hydrocarbon degradation is an important biogeochemical process in oil reservoirs; however, genomic DNA-based analysis of microorganisms and metabolite detection are not conclusive for identification of the ongoing nature of this bioprocess. In this study, a suite of analyses, involving the study of microbial community and selective gene quantification of both genomic DNA and RNA together with signature metabolites, were performed to comprehensively advance the understanding of the methanogenic biodegradation of hydrocarbons in a low-temperature oilfield. The fumarate addition products for alkanes—C4, C5, and C7-alkylsuccinates—and transcribed assA and mcrA genes were simultaneously detected in the production water sample, providing robust and convincing evidence for both the initial activation of n-alkanes and methane metabolism in this oilfield. The clone library of assA gene transcripts showed that Smithella was active and most likely responsible for the addition of fumarate to n-alkanes, whereas Methanoculleus and Methanothrix were the dominant and active methane-producers via CO2 reduction and acetoclastic pathways, respectively. Additionally, qPCR results of assA and mcrA genes and their transcribed gene copy numbers revealed a roughly similar transcriptional activity in both n-alkanes-degraders and methane producers, implying that they were the major participants in the methanogenic degradation of n-alkanes in this oilfield. To the best of our knowledge, this is the first report presenting sufficient speculation, through detection of signature intermediates, corresponding gene quantification at transcriptional levels, and microbial community analysis, of methanogenic degradation of n-alkanes in production water of an oil reservoir.

KW - Alkanes

KW - Biodegradation

KW - Fumarate addition

KW - Methanogenesis

KW - Oil reservoir

KW - Transcripts

UR - http://www.scopus.com/inward/record.url?scp=85088870097&partnerID=8YFLogxK

U2 - 10.1016/j.scitotenv.2020.141290

DO - 10.1016/j.scitotenv.2020.141290

M3 - 文章

C2 - 32745846

AN - SCOPUS:85088870097

SN - 0048-9697

VL - 746

JO - Science of the Total Environment

JF - Science of the Total Environment

M1 - 141290

ER -