title: Direct evidences on bacterial growth pattern regulating pyrene degradation pathway and genotypic dioxygenase expression.
abstract: Pyrene degradation by Mycobacterium sp. strain A1-PYR was investigated in the presence of nutrient broth, phenanthrene and fluoranthene, respectively. Fast bacterial growth in the nutrient broth considerably enhanced pyrene degradation rate, whereas degradation efficiency per cell was substantially decreased. The addition of nutrient broth could not alter the transcription levels of all dioxygenase genotypes. In the PAH-only substrates, bacterial growth completely relied on biological conversion of PAHs into the effective carbon sources, which led to a higher degradation efficiency of pyrene per cell than the case of nutrient broth. Significant correlations were only observed between nidA-related dioxygenase expression and pyrene degradation or bacterial growth. The highest pyrene degradation rate in the presence of phenanthrene was consistent with the highest transcription level of nidA and 4,5-pyrenediol as the sole initial metabolite. This study reveals that bacterial growth requirement can invigorate degradation of PAHs by regulating metabolic pathway and genotypic enzyme expression.
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Baowei
authors.initials: B
authors.lastname: Chen
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Jinyin
authors.initials: J
authors.lastname: Huang
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Yuan
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Lin
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Yang
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China. Electronic address: cesltg@mail.sysu.edu.cn.
authors.forename: Tiangang
authors.initials: T
authors.lastname: Luan
mesh_terms: D001673:Biodegradation, Environmental; D049308:Dioxygenases / Q000235:genetics* / Q000378:metabolism; D005449:Fluorenes / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D009161:Mycobacterium / Q000378:metabolism*; D010616:Phenanthrenes / Q000378:metabolism; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D011721:Pyrenes / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D005449:Fluorenes; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D014874:Water Pollutants, Chemical; C007738:fluoranthene; D049308:Dioxygenases
keywords: Bacterial growth; Biodegradation; Dioxygenase; Polycyclic aromatic hydrocarbons; Pyrene