降解甲氰菊酯光合细菌的分离鉴定及其降解特性研究

Isolation and Identification of Fenpropathrin Degrading Strain PSB07-15 and Its Degradation Characteristics

采用富集分离法从农药厂污泥中分离到一株能降解甲氰菊酯(fenpropathrin)的光合细菌新菌株PSB07-15,通过形态特征、生理生化特征以及对16SrDNA序列(Genbank Accession No.EU005383)进行了同源比较、鉴定。结果表明,该菌株为沼泽红假单孢菌(Rhodopseudomonas palustris)。生长特性和甲氰菊酯降解实验结果表明,该菌株的最适生长温度为30℃,最适pH为6.5。该菌以共代谢方式降解甲氰菊酯,对甲氰菊酯的最高耐受浓度为600mg·L-1,培养15d对600mg·L-1甲氰菊酯降解率达35.26%。通过GC-MS对降解产物进行了分析,结果显示间苯氧基苯乙腈是展出惟一的降解产物,推测该菌的降解途径是可能作用于甲氰菊酯的酯键处。本研究工作为利用光合细菌进行生物修复提供了理论依据。

A photosynthetic bacterial strain PSB07-15, which was capable of degrading fenpropathrin, was isolated from the sludge of pesticide factory by enrichment media. PSB07-15 was identified as Rhodopseudomonas palustris based on its morphology, physiology and homol- ogy of 16S rDNA gene sequence（Genbank Accession No. EU005383）. The growth and degrading characteristics of this strain were tested. The results showed that 30℃, pH6.5 were the optimum growth conditions of PSB07-15. Further experiments suggested that PSB07-15 could grow in the media supplied with fenpropathrin up to 600 mg·L^-1 and degrades fenpropathrin by cometabolic way. PSB07-15 degraded 35.26% fenpropathrin in a concentration of 600 mg·L^-1 within 15 d. The metabolic products, which were assessed by gas chromatography with mass selected detection, identified m-phenoxyphenyl-acetonitril as the only stable metabolic products and from this a fenpropathrin biodegradation pathway was proposed. Our results showed that PSB07-15 may potentially be used in bioremediation.