氯氰菊酯降解菌GF31的分离鉴定及其降解特性

Isolation, Identification and Characteristics of a Cypermethrin-degrading Bacterium GF31

摘要:

从受污染的土壤中分离得到1株以氯氰菊酯为唯一碳源生长的降解菌GF31, 通过形态观察、16S rDNA基因序列分析、生理生化实验, 鉴定该菌为铜绿假单胞菌(Pseudomonas aeruginosa)。菌株GF31降解氯氰菊酯的最佳pH值为7.0, 接种量为10%, 对浓度高达300 mg/L的菊酯仍可保持较高的降解活性。外加氮源对菌株的降解效能影响显著, 有机氮比无机氮更有利于农药降解。当以0.5 g/L蛋白胨作为氮源时, 降解速率明显提高, 对100 mg/L氯氰菊酯降解的平均速率为13.64 mg/(L·d), 是以硫酸铵为氮源时的2倍。初步分析认为降解产物及碱性pH环境对菌株的生长及活性具有一定的抑制作用。

Abstract:

A bacterium strain named GF31, which could use cypermethrin as the sole source of carbon, was isolated from a polluted soil. Through morphological observation, 16S rDNA genetical analysis, physiological and biochemical tests, the strain GF31 was identified as Pseudomonas aeruginosa. The optimal pH and inoculating quantity for the cypermethrin degradation were 7.0 and 10%, respectively. The degradation activity of strain GF31 could keep at a high level even when the cypermethrin concentration was increased to 300 mg/L. Furthermore, nitrogen sources were proved to be able to accelerate the degradation rate, especially the organic nitrogen sources. When 0.5 g/L peptone was added, the average degrading rate of 100 mg/L was 13.64 mg/(L·d), which was two times as that of the ammonium sulfate. It was preliminarily speculated that the degraded products and the alkaline environment might inhibit the growth and activity of strain GF31.