氯氰菊酯降解菌CY22-7的分离鉴定及降解特性研究

Isolation and characterization of a new cypermethrin degrading bacterium CY22-7

从采集的多种土壤样品中,获得了19株在3种筛选平板上均生长良好的候选氯氰菊酯降解菌。通过生理生化特性鉴定和16SrDNA序列的测定及比对,将其中的氯氰菊酯降解菌CY22-7鉴定为中华根瘤菌属(Sinorhizobiumsp.)。同时,对氯氰菊酯降解菌CY22-7的降解特性研究结果表明:(1)氯氰菊酯降解菌CY22-7以5%(体积分数)的接种量接种到氯氰菊酯起始质量浓度为100mg/L的氯氰菊酯乙醇培养基后,于200r/min、30℃摇床中培养。经过6d的培养,氯氰菊酯降解菌CY22-7降解了约60%的氯氰菊酯。(2)加入外源营养物质有利于促进氯氰菊酯的降解。其中,葡萄糖和酵母提取物的促进作用最为明显。(3)氯氰菊酯降解菌CY22-7降解氯氰菊酯的最适温度为30℃,最佳pH为6.0。

A cypermethrin-degrading bacterium named CY22-7 was isolated from pesticide contaminated soils. This bacterium was identified as Sinorhizobium sp. according to its physiological and biochemical characteristics and the similarity analysis of its 16S rDNA sequence. Under the inorganic salt medium with the bacterium inoculation of 50%,60℃ of 100 mg/L cypermethrin was degraded by this strain in 6 d at 30℃. The effects of initial pesticide con centration,added nutriment,temperature,and pH on cypermethrin degrading by CY22-7 was also investigated. The presence of glucose and yeast extract were beneficial for cypermethrin degrading.