Characterization of a novel cyfluthrin-degrading bacterial strain Brevibacterium aureum and its biochemical degradation pathway

• Published in: Bioresource technology Vol. 132; pp. 16 - 23
• Main Authors: Chen, Shaohua, Dong, Yi Hu, Chang, Changqing, Deng, Yinyue, Zhang, Xi Fen, Zhong, Guohua, Song, Haiwei, Hu, Meiying, Zhang, Lian-Hui
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.03.2013; Elsevier
• Subjects: acids; Bacteria; biochemical pathways; Biodegradation; Biodegradation, Environmental; Biological and medical sciences; bioremediation; Biotechnology; Brevibacterium; Brevibacterium - metabolism; Brevibacterium aureum; Cyfluthrin; Degradation; Degradation pathway; Environmental Pollutants; Environmental Pollutants - metabolism; Fundamental and applied biological sciences. Psychology; Insecticides; Insecticides - metabolism; Kinetics; metabolism; Metabolites; microbiology; Nitriles; Nitriles - metabolism; Pathways; Phenol; Pyrethrins; Pyrethrins - metabolism; response surface methodology; Sewage; Sewage - microbiology; sludge; Strain; Biodegradation; Brevibacterium aureum; Kinetics; Cyfluthrin; Degradation pathway; Insecticide; Biochemical property; Pesticides; Brevibacteriaceae; Pyrethroids; Strain; Brevibacterium; Bacteria; Actinomycetes
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2013.01.002

► A new bacterium Brevibacterium aureum was isolated and characterized. ► It utilizes cyfluthrin as a growth substrate and degrades high concentrations. ► The bacterium was able to degrade a wide range of other pyrethroid insecticides. ► A novel degradation pathway for cyfluthrin was proposed based on the metabolites. ► The bacterium harbors the metabolic pathway for the detoxification of cyfluthrin. Brevibacterium aureum DG-12, a new bacterial strain isolated from active sludge, was able to degrade and utilize cyfluthrin as a growth substrate in the mineral medium. Response surface methodology using central composite rotatable design of cultural conditions was successfully employed for optimization resulting in 88.6% degradation of cyfluthrin (50mgL−1) within 5days. The bacterium degraded cyfluthrin by cleavage of both the carboxylester linkage and diaryl bond to form 2,2,3,3-tetramethyl-cyclopropanemethanol, 4-fluoro-3-phenexy-benzoic acid, 3,5-dimethoxy phenol, and phenol, and subsequently transformed these compounds with a maximum specific degradation rate, half-saturation constant and inhibition constant of 1.0384day−1, 20.4967mgL−1, and 141.9013mgL−1, respectively. A novel degradation pathway for cyfluthrin was proposed based on analysis of these metabolites. In addition, this strain was found capable of degrading a wide range of synthetic pyrethroid insecticides. Our results suggest that B. aureum DG-12 may be an ideal microorganism for bioremediation of the pyrethroid-contaminated environments.