title: Dynamic processes of indigenous microorganisms from a low-temperature petroleum reservoir during nutrient stimulation.
abstract: Compared to medium-high temperature petroleum reservoirs (30°C-73°C), little is known about microbial regulation by nutrients in low-temperature reservoirs. In this study, we report the performance (oil emulsification and biogas production) and community structure of indigenous microorganisms from a low-temperature (22.6°C) petroleum reservoir during nutrient stimulation. Culture-dependent approaches indicated that the number of hydrocarbon-oxidizing bacteria (HOB), nitrate-reducing bacteria (NRB) and methane-producing bacteria (MPB) increased by between 10- and 1000-fold, while sulfate-reducing bacteria (SRB) were observed at low levels during stimulation. Phylogenetic analysis of the 16S rRNA gene indicated that Pseudomonas, Ochrobactrum, Acinetobacter, Halomonas and Marinobacter, which have the capability to produce surfactants, were selectively enriched. Methanoculleus, Methanosaeta, Methanocorpusculum and Methanocalculus showed the largest increase in relative abundance among archaea. Micro-emulsion formed with an average oil droplet diameter of 14.3 μm (ranging between 4.1 μm and 84.2 μm) during stimulation. Gas chromatographic analysis of gas production (186 mL gas/200 mL medium) showed the levels of CO2 and CH4 increased 8.97% and 6.21%, respectively. Similar to medium-high temperature reservoirs, HOB, NRB, SRB and MPB were ubiquitous in the low-temperature reservoir, and oil emulsification and gas production were the main phenomena observed during stimulation. Oil emulsification required a longer duration of time to occur in the low-temperature reservoir.
authors: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, PR China; College of Life Sciences, Nankai University, Tianjin 300071, PR China.
authors: Pei-Ke
authors: PK
authors: Gao
authors: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, PR China; College of Life Sciences, Nankai University, Tianjin 300071, PR China.
authors: Guo-Qiang
authors: GQ
authors: Li
authors: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, PR China; College of Life Sciences, Nankai University, Tianjin 300071, PR China.
authors: Ling-Xia
authors: LX
authors: Zhao
authors: Research Institute of Experiment and Detection, Xinjiang Oilfield Company, Karamay 834000, PR China.
authors: Xue-Cheng
authors: XC
authors: Dai
authors: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, PR China; College of Life Sciences, Nankai University, Tianjin 300071, PR China.
authors: Hui-Mei
authors: HM
authors: Tian
authors: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, PR China; College of Life Sciences, Nankai University, Tianjin 300071, PR China.
authors: Liu-Bing
authors: LB
authors: Dai
authors: Research Institute of Experiment and Detection, Xinjiang Oilfield Company, Karamay 834000, PR China.
authors: Hong-Bo
authors: HB
authors: Wang
authors: Department of Agronomy, Tianjin Agriculture University, Tianjin 300384, PR China.
authors: Hai-Dong
authors: HD
authors: Huang
authors: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, PR China; College of Life Sciences, Nankai University, Tianjin 300071, PR China.
authors: Yue-Hua
authors: YH
authors: Chen
authors: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, PR China; College of Life Sciences, Nankai University, Tianjin 300071, PR China. Electronic address: tingma@nankai.edu.cn.
authors: Ting
authors: T
authors: Ma
mesh_terms: D001105:Archaea / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D056804:Biofuels / Q000600:supply & distribution; D003080:Cold Temperature; D004655:Emulsions; D006838:Hydrocarbons / Q000378:metabolism; D008697:Methane / Q000378:metabolism; D008965:Molasses; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D010578:Petroleum / Q000382:microbiology*; D010710:Phosphates / Q000378:metabolism / Q000494:pharmacology; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013431:Sulfates / Q000378:metabolism; D013501:Surface-Active Agents / Q000378:metabolism; D013997:Time Factors
chemical_list: D056804:Biofuels; D004655:Emulsions; D006838:Hydrocarbons; D009566:Nitrates; D010578:Petroleum; D010710:Phosphates; D012336:RNA, Ribosomal, 16S; D013431:Sulfates; D013501:Surface-Active Agents; C031618:sodium nitrate; D008697:Methane
keywords: 16S rRNA gene; Emulsification; Indigenous microorganisms; Petroleum reservoir; Stimulation