Characteristics of hydrocarbon hydroxylase genes in a thermophilic aerobic biological system treating oily produced wastewater

• Published in: Water science and technology 2015, Vol.71 (1), p.75-82
• Main Authors: Liu, Ruyin, Gao, Yingxin, Ji, Yifeng, Zhang, Yu, Yang, Min
• Format: Article
• Language: English
• Subjects: Abundance; Activation; Aerobiosis; Alkanes; Aromatic compounds; Aromatic hydrocarbons; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Betaproteobacteria - enzymology; Betaproteobacteria - genetics; Biodegradation; Biofilms; Bioreactors - microbiology; Bioremediation; Chemical oxygen demand; Clones; Cloning; Cytochrome; Cytochrome P-450 CYP4A - genetics; Cytochrome P-450 CYP4A - metabolism; Deoxyribonucleic acid; Dioxygenase; Dioxygenases - genetics; Dioxygenases - metabolism; DNA; Gene sequencing; Genes; Gram-Negative Aerobic Rods and Cocci - enzymology; Gram-Negative Aerobic Rods and Cocci - genetics; Haem; Homology; Hot Temperature; Hydrocarbons; Hydroxylase; Mixed Function Oxygenases - genetics; Mixed Function Oxygenases - metabolism; Molecular Sequence Data; Monooxygenase; Nucleotide sequence; Oil and gas fields; Oil field equipment; Oil fields; Oxidation; PCR; Phylogenetics; Phylogeny; Polycyclic aromatic hydrocarbons; Polymerase chain reaction; Relative abundance; RNA, Ribosomal, 16S - genetics; RNA, Ribosomal, 16S - metabolism; rRNA 16S; Sequence Analysis, DNA; Studies; Thermophilic bacteria; Waste Disposal, Fluid; Wastewater; Wastewater treatment; Water quality; Water treatment
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2014.470

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.