摘要
菊酯类农药广泛用于农业害虫的防治,但对生态环境与食品的污染也是十分严重的,微生物降解菊酯类农药是消除其污染的主要途径。从农药厂废水排放口附近的活性污泥中分离到一株能利用功夫菊酯为惟一碳源生长的细菌,命名为GF-3。根据其生理生化特征和16SrDNA序列相似性分析,将该菌株鉴定为芽孢杆菌属(Bacillus sp.)。采用室内培养与液相色谱测定方法,研究了GF-3对功夫菊酯的降解特性。结果表明,GF-3能有效地降解浓度为50～600mg·L-1的功夫菊酯,在24h内对100mg·L-1功夫菊酯的降解率达到98.4%。降解功夫菊酯的适宜温度为30℃左右,适宜pH为7～10。酶的定域试验表明,降解功夫菊酯的酶属于胞外酶。GF-3除了降解功夫菊酯外,还能降解甲氰菊酯、氯氰菊酯、溴氰菊酯、高效氯氰菊酯等。GF-3中有2个质粒,但质粒消除试验表明降解功夫菊酯的基因不在质粒上,而是在其染色体DNA上。
Pyrethroids were widely used to prevent pests in agriculture and resulted in severely environmental pollution, Microbial degradation was an effective way to remove the pyrethroids contamination from environment. A bacterium, GF-3, capable of utilizing cyhalothrin, a kind of pyrethroids, as sole carbon source was isolated from activated sludge collected from waste water-treating system of cyhalothrin manufacturer. The GF-3 cells were rod, Gram positive with side flagella and spore-forming. The colonies on LB media were milk-white in color, circular, and smooth. The ceils were positive for catalase and glutin-degradation test. No pigments were produced. GF-3 strain was identified as Bacillus sp. according to its physiological and biochemical characteristics and 16S rDNA sequence similarity analysis. The GF-3 strain could effectively degrade cyhalothrin ranging of 50-600 mg· L^-1. 100 mg· L^-1 cyhalothrin could be almost completely degraded by GF-3 strain in 24 h. The optimal pH and temperature for GF-3 strain to degrade cyhalothrin were pH7-10 and 30 ℃ respectively. The enzyme analysis showed that the enzyme responsible for the cyhalothrin degradation was extracellular. Besides cyhalothrin the strain of GF-3 was also able to degrade other pyrethroids such as fenpropathrin, cypermethrin, deltamethrin, beta cypermethrin, fenvalerate and bifenthrin. Degradation of fenpropathrin and cyhalothrin by GF-3 was best among the above pyrethroids, while fenvalerate and bifenthrin were poorly degraded by GF- 3. There were two plasmids in GF-3, but none was related to the cyhalothrin degradation because after plasmids curing GF-3 strain could still degrade cyhalothrin.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2009年第7期1545-1551,共7页
Journal of Agro-Environment Science
基金
科技部农业微生物菌种资源整理整合及共享试点(2005DKA21201-11)
作者简介
徐莲（1979-），女，河南平顶山人，硕士研究生。E—mail：2006116062@njau．edu．cn
通讯作者：沈标E-mail：shenbiao@njau．edu．cn
