title: Insights into the Anaerobic Biodegradation Pathway of n-Alkanes in Oil Reservoirs by Detection of Signature Metabolites.
abstract: Anaerobic degradation of alkanes in hydrocarbon-rich environments has been documented and different degradation strategies proposed, of which the most encountered one is fumarate addition mechanism, generating alkylsuccinates as specific biomarkers. However, little is known about the mechanisms of anaerobic degradation of alkanes in oil reservoirs, due to low concentrations of signature metabolites and lack of mass spectral characteristics to allow identification. In this work, we used a multidisciplinary approach combining metabolite profiling and selective gene assays to establish the biodegradation mechanism of alkanes in oil reservoirs. A total of twelve production fluids from three different oil reservoirs were collected and treated with alkali; organic acids were extracted, derivatized with ethanol to form ethyl esters and determined using GC-MS analysis. Collectively, signature metabolite alkylsuccinates of parent compounds from C1 to C8 together with their (putative) downstream metabolites were detected from these samples. Additionally, metabolites indicative of the anaerobic degradation of mono- and poly-aromatic hydrocarbons (2-benzylsuccinate, naphthoate, 5,6,7,8-tetrahydro-naphthoate) were also observed. The detection of alkylsuccinates and genes encoding for alkylsuccinate synthase shows that anaerobic degradation of alkanes via fumarate addition occurs in oil reservoirs. This work provides strong evidence on the in situ anaerobic biodegradation mechanisms of hydrocarbons by fumarate addition.
authors.affiliation: 1] State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, P.R. China [2] Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, P.R. China.
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Bian
authors.affiliation: 1] State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, P.R. China [2] Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, P.R. China.
authors.forename: Serge Maurice
authors.initials: SM
authors.lastname: Mbadinga
authors.affiliation: 1] State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, P.R. China [2] Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, P.R. China.
authors.forename: Yi-Fan
authors.initials: YF
authors.lastname: Liu
authors.affiliation: 1] State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, P.R. China [2] Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, P.R. China.
authors.forename: Shi-Zhong
authors.initials: SZ
authors.lastname: Yang
authors.affiliation: 1] State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, P.R. China [2] Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, P.R. China.
authors.forename: Jin-Feng
authors.initials: JF
authors.lastname: Liu
authors.affiliation: 1] State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, P.R. China [2] Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, P.R. China.
authors.forename: Ru-Qiang
authors.initials: RQ
authors.lastname: Ye
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China.
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Gu
authors.affiliation: 1] State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, P.R. China [2] Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, P.R. China.
authors.forename: Bo-Zhong
authors.initials: BZ
authors.lastname: Mu
mesh_terms: D000473:Alkanes / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001673:Biodegradation, Environmental; D004269:DNA, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D010578:Petroleum / Q000382:microbiology*
chemical_list: D000473:Alkanes; D004269:DNA, Bacterial; D010578:Petroleum