阿维菌素降解菌株AW70的分离鉴定及降解特性研究

Isolation and Identification of an Avermectins Degrading Strain AW70 and Its Degrading Characteristics

从长期受阿维菌素农药污染的土壤中分离到一株能高效降解阿维菌素的菌株AW70。结合生理生化实验和16SrDNA序列同源性分析,将该菌株鉴定为伯克霍尔德氏菌属(Burkholderiasp.),GenBank登录号为EU295449。菌株AW70能利用阿维菌素为唯一C源生长,在温度25℃～42℃和pH6.5～8.5范围时降解能力较好,其最适降解温度为30℃,最适初始pH值为7。48h对50mg/kg阿维菌素的降解率大于85%。南丰蜜桔上农药降解试验结果表明,喷施菌株AW70菌剂的蜜桔中未检测到阿维菌素的残留,表明该菌株具有良好的应用前景。

A bacterium （AW70） capable of degrading avermectins was successfully isolated from the long-term avermectins polluted soil. This strain was identified as Burkholderia sp. based on the physiological ＆ biochemical characteristics and homology analysis of its 16S rDNA sequence. AW70 could use avermectins as the sole-carbon source for growth and it could maintain the good degrading ability at the temperature of 25 ℃- 42℃ and initial pH value of 6.5 - 8.5. The most adaptable initial pH value and temperature for the degradation of avermectins were 7.0 and 37℃ under which more than 85% of the pesticide could be degraded within 48 h. In the bioremediation of avermectins contamination on oranges in Nanfeng, Jiangxi province, AW70 could degrade 0.247 mg/kg avermectins to non-detectable level, indicating that the strain has a great potential application.