【摘要】 采用室内培养方法,对分离到的一株具有降解甲基对硫磷活性的细菌进行了鉴定,并对其降解性能进行了研究。通过形态观察、生理生化特征及16SrDNA同源性分析将其初步鉴定到属,并确定为产碱菌属的一个新种,命名为Alcaligenes.sp.YcX-20,16SrDNA序列在GenBank中注册号为AY628412。其酯酶活性随菌液浓度和培养时间的增加呈上升趋势;在基础培养基中可耐受700mg·L-1的甲基对硫磷,在普通培养基中耐受浓度达2500mg·L-1;X-20可降解甲基对硫磷形成对硝基苯酚;以甲基对硫磷为惟一碳源时,30℃培养30h降解率达60%。更多还原

【Abstract】 The present study isolated a bacterium strain X-20 from activated sludge of Huayang Pesticide Factory by liquid enrichment culture. The bacteria were found to be able to use methyl parathion as sole carbon source and degrade it to p-nitrophenol, leading reduction of its toxicity by 100~200 times. The strain is characterized by its short rod-shaped gram-negative bacterium, with no flagella, barely moving, the optimum temperature of grow is at 30 ℃ but can tolerant at 40 ℃. Through chemotaxonomic characterizations and phylogenetic inference based on 16S rDNA sequence and analysis, the strain was identified as a member of the genus and was named as Alcaligenes.sp.YcX-20, GenBank accession number of the 16S rDNA sequence is AY628412. The strain can tolerant high concentration of methyl parathion at 700 mg·L-1 in basic medium and up to 2 500 mg·L-1 in ordinary medium. Activity of the esterase increase with the increasing of the bacterium concentration, which is useful to degrade methyl parathion . Using 50 mg·L-1 methyl parathion as sole carbon source, the strain was able to degrade 60% of the pesticide in 30 hours at 30℃, pH7.0.更多还原