title: Characteristics of hydrocarbon hydroxylase genes in a thermophilic aerobic biological system treating oily produced wastewater.
abstract: Alkane and aromatic hydroxylase genes in a full-scale aerobic system treating oily produced wastewater under thermophilic condition (45-50 °C) in the Jidong oilfield, China, were investigated using clone library and quantitative polymerase chain reaction methods. Rather than the normally encountered integral-membrane non-haem iron monooxygenase (alkB) genes, only CYP153-type P450 hydroxylase genes were detected for the alkane activation, indicating that the terminal oxidation of alkanes might be mainly mediated by the CYP153-type alkane hydroxylases in the thermophilic aerobic process. Most of the obtained CYP153 gene clones showed distant homology with the reference sequences, which might represent novel alkane hydroxylases. For the aromatic activation, the polycyclic aromatic hydrocarbon-ring hydroxylating dioxygenase (PAH-RHD) gene was derived from Gram-negative PAH-degraders belonging to the Burkholderiales order, with a 0.72% relative abundance of PAH-RHD gene to 16S rRNA gene. This was consistent with the result of 16S rRNA gene analysis, indicating that Burkholderiales bacteria might play a key role in the full-scale process of thermophilic hydrocarbon degradation.
authors.affiliation: College of Environmental and Resource Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China E-mail: yingxingao@sina.com.
authors.forename: Ruyin
authors.initials: R
authors.lastname: Liu
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China E-mail: yingxingao@sina.com.
authors.forename: Yingxin
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China E-mail: yingxingao@sina.com; Zhejiang University, Hangzhou 310058, China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Ji
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China E-mail: yingxingao@sina.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China E-mail: yingxingao@sina.com.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
mesh_terms: D000332:Aerobiosis; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D020562:Betaproteobacteria / Q000201:enzymology* / Q000235:genetics*; D019149:Bioreactors / Q000382:microbiology; D042926:Cytochrome P-450 CYP4A / Q000235:genetics* / Q000378:metabolism; D049308:Dioxygenases / Q000235:genetics* / Q000378:metabolism; D016946:Gram-Negative Aerobic Rods and Cocci / Q000201:enzymology* / Q000235:genetics*; D006358:Hot Temperature; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014865:Waste Disposal, Fluid
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D006899:Mixed Function Oxygenases; D049308:Dioxygenases; D042926:Cytochrome P-450 CYP4A