Sphingobium sp．JZ-1对菊酯类农药的降解特性研究

CHARACTERISTICS OF SPHINGOBIUM SP. JZ-1 DEGRADING PYRETHROID PESTICIDES

研究了菊酯降解菌株Sphingobium sp.JZ-1及其粗酶液对菊酯类农药的降解特性。结果表明,该菌能降解目前使用的各种菊酯类农药,降解速率顺序为:氯菊酯>甲氰菊酯≈氯氰菊酯>功夫菊酯>氰戊菊酯>溴氰菊酯>联苯菊酯;Sphingobium sp.JZ-1对菊酯的降解没有手性选择性;高效液相色谱检测结果表明Sphingobium sp.JZ-1对氯氰菊酯降解的初始反应是在菊酯水解酶的催化下羧酸酯键断裂生成二氯菊酸和3-苯氧基苯甲醛,3-苯氧基苯甲醛进一步氧化成苯氧基苯甲酸。Sphingobium sp.JZ-1细胞中菊酯水解酶酶活不需要菊酯的诱导。

Characteristics of pyrethriod-degrading strain Sphingobium sp. JZ-1 and its crude enzyme extract degrading pyrethriod were investigated in this experiment. The strain was capable of degrading a wide range of pyrethroid pesticides, which followed a descending order of permethrin 〉 fenpropathrin ≈ cypermethrin 〉 cyhalothrin 〉 fenvalerate 〉 dehamethrin 〉 bifenthrin in degradation rate. No chiral selectivity was observed in biodegrading pyrethroid isomers. The initial reaction of Sphingobium sp. JZ-1, in degrading cypermethrin was to break carboxylic acid ester bonds under the catalysis of permethrin hydrolase yielding equimolar amounts of dichloroving acid （DCVA） and 3-phenoxybenzaldehyde, which was then oxidized into phenoxybenzoic acid. The pyrethroid hydrolase in Sphingobium sp. JZ-1 was expressed without pyrethroid induction.