title: Biodegradation of beta-cypermethrin and 3-phenoxybenzoic acid by a novel Ochrobactrum lupini DG-S-01.
abstract: A newly isolated bacterium DG-S-01 from activated sludge utilized beta-cypermethrin (beta-CP) and its major metabolite 3-phenoxybenzoic acid (3-PBA) as sole carbon and energy source for growth in mineral salt medium (MSM). Based on the morphology, physio-biochemical characteristics, and 16S rDNA sequence analysis, DG-S-01 was identified as Ochrobactrum lupini. DG-S-01 effectively degraded beta-CP with total inocula biomass A(590 nm) = 0.1-0.8, at 20-40 °C, pH 5-9, initial beta-CP 50-400 mg L(-1) and metabolized to yield 3-PBA leading to complete degradation. Andrews equation was used to describe the special degradation rate at different initial concentrations. Degradation rate parameters q(max), K(s) and K(i) were determined to be 1.14 d(-1), 52.06 mg L(-1) and 142.80 mg L(-1), respectively. Maximum degradation was observed at 30 °C and pH 7.0. Degradation of beta-CP was accelerated when MSM was supplemented with glucose, beef extract and yeast extract. Studies on biodegradation in liquid medium showed that over 90% of the initial dose of beta-CP (50 mg L(-1)) was degraded under the optimal conditions within 5d. Moreover, the strain also degraded beta-cyfluthrin, fenpropathrin, cyhalothrin and deltamethrin. These results reveal that DG-S-01 may possess potential to be used in bioremediation of pyrethroid-contaminated environment.
authors.affiliation: Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Laboratory of Insect Toxicology, South China Agricultural University, Guangzhou 510642, PR China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Chen
authors.forename: Meiying
authors.initials: M
authors.lastname: Hu
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.forename: Guohua
authors.initials: G
authors.lastname: Zhong
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.forename: Muhammad
authors.initials: M
authors.lastname: Rizwan-ul-Haq
authors.forename: Haitao
authors.initials: H
authors.lastname: Han
mesh_terms: D001483:Base Sequence; D001565:Benzoates / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers; D006863:Hydrogen-Ion Concentration; D007306:Insecticides / Q000378:metabolism*; D007700:Kinetics; D042041:Ochrobactrum / Q000378:metabolism*; D010802:Phylogeny; D011722:Pyrethrins / Q000378:metabolism*
chemical_list: D001565:Benzoates; D017931:DNA Primers; D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin; C017618:3-phenoxybenzoic acid