砜嘧磺隆降解菌的分离及特性研究

为了进行砜嘧磺隆污染的生物修复,从农药厂废水排放口的污泥中,通过富集培养和平板稀释法,分离筛选出一株具有较强降解砜嘧磺隆特性的菌株N2.通过形态观察及生理生化试验对其进行鉴定,同时对其性质进行了初步研究.结果表明,该菌株为沙雷氏菌属(Serratia marcecens);该菌株降解砜嘧磺隆的最适温度为30～35 ℃,最适pH值为6.0,适宜接种量(预培养24 h,离心后用缓冲液洗涤的菌种OD_600值为0.897)为1.0%(V/V),在72 h内对20 mg/L的砜嘧磺隆降解率为93.71%;随砜嘧磺隆质量浓度升高,降解率下降.研究表明该菌株有很好的实际应用价值.

Isolation and characterization of rimsulfuron segrading strain N2

This paper intends to introduce our experience on isolating a strain of bacteria named N2 capable of degrading rimsulfuron from the activated sludge obtained from the sewage treating in the pesticide-making factories by using a kind of enriched culture. The said rimsulfuron here is one of the sulfonylurea herbicides commonly used all over the world controlling grass weeds and broad-leave weeds in the corn fields with the insect pests acting as harm-makers. In addition, the residue of the herbicide application may also bring a potential threat both to the health of human beings and that to other animals, for which reason, the use of these herbicides should be limited. So far as we know, a number of microbial groups can be found to degrade or transform the herbicides, including some kinds of bacteria. The strain named N2 mentioned above can be used as rimsulfuron with carbon source being concurrent. We have also disclosed the physiological and biochemical features of Serratia marcecens preliminarily in addition to the analysis of the rimsulfuron of degradation by means of GC. The results of our study show that strain N2 helps to degrade rimsulfuron with the optimal pH value with the temperature for the growth and degradation of rimsulfuron being 3035 ℃ and 6.0 respectively at a rate of inoculating amount of 1.0%. With the initial concentration of 20 mg/L , the degradation rate of rimsulfuron can be as high as 93.71% in 72 h, However, if the initial concentration is higher than 20 mg/L, the biodegradation rate would be reduced slightly in case the initial concentration of rimsulfuron tends to grow. Thus, it can be seen that the present paper can be said to have provided a scientific evidence for the applications of bioremediation and control of environmental pollution.