氯氰菊酯降解菌的筛选鉴定及其降解特性研究

从农药厂废水排放口附近的污泥中分离到1株能降解氯氰菊酯的细菌LQ-3.根据其形态、生理生化特征和16S rDNA(GenBank Accession No.FJ222585)序列分析,将该菌株鉴定为Starkeya sp..LQ-3菌株只能以共代谢方式降解氯氰菊酯,在有酵母粉、蛋白胨、葡萄糖等营养物质存在的条件下,5 d内对20 mg·L-1氯氰菊酯的降解率达到72.1%.LQ-3菌株降解氯氰菊酯的最适温度为30 ℃左右,pH值为7～8.LQ-3菌株还能降解功夫菊酯、甲氰菊酯、联苯菊酯和溴氰菊酯.酶的定域试验表明,LQ-3菌株降解氯氰菊酯的酶属于胞外酶.

Isolation and Identification of a Strain of Cypermethrin-Degrading Bacteria LQ-3 and Its Degradation Characteristics

A strain of cypermethrin-degrading bacteria referred to as LQ-3 was isolated from sludge collected from a wastewater outlet of a pesticide plant.Based on morphological,physiological and biochemical characteristics and 16S rDNA sequences analysis (GenBank Accession No.FJ222585),LQ-3 was identified as Starkeya sp..LQ-3 degraded cypermethrin through co-metabolism.When fed with nutrient substances,such as yeast extract,peptone and glucose,LQ-3 could degrade 72.1% of cypermethrin in the medium (20 mg·L-1) in 5 d.The optimal pH and temperature for the degradation by LQ-3 was 7-8 and 30 ℃,respectively.Strain LQ-3 was also able to degrade other pyrethroids such as cyhalothrin,fenpropathrin,bifenthrin and deltamethrin besides cypermethrin.The enzyme distribution experiment showed that the enzyme responsible for the cypermethrin degradation was extracellular.