久效磷降解菌的分离及其酶促降解特性研究  

Isolation of a Monocrotophos-Degrading Bacterial Strain and Characterization of Enzymatic Degradation

作　　者：贾开志[1] 李晓慧[1] 何健[1] 顾立锋[1] 马吉平[1] 李顺鹏[1] 

机构地区：[1]南京农业大学生命科学学院农业部农业环境微生物工程重点开放实验室,南京210095

出　　处：《环境科学》2007年第4期908-912,共5页Environmental Science

基　　金：农业部成果转化项目(农技函2004514);农业部科教司基金项目(200557);科技部教科司成果转化项目(2004;24a)

摘　　要：从某农药厂废水处理池的污泥中分离到1株久效磷高效降解菌株M-1,经过对其形态特征、生理生化、以及16S rDNA序列分析,该菌株初步鉴定为Paracoccus sp..M-1能以久效磷作为唯一碳源生长,24 h对100 mg.L-1久效磷的降解效率为92.47%.久效磷降解酶定域表达试验表明该酶为胞内酶,组成表达.久效磷酶促降解的最适反应pH为8.0,最适反应温度为25℃;其米氏常数(Km)为0.29μmol.mL-1,最大降解速率(Vmax)为682.12μmol.(min.mg)-1.久效磷降解酶热稳定性差,碱性条件下能够保持较高降解活性.A monocrotophos [ dimethyl （ E）- 1-2-methylcarbamoylvinylphosphate or MCP ] -degrading strain named as M-1 was isolated from sludge collected from the wastewater treatment pool of a pesticide factory and identified as Paracoccus sp. according to its morphology and biochemical properties and 16S rDNA sequence analysis. Using MCP as a sole carbon source, M-1 was able to degrade MCP（ 100 mg· L^- 1 ） by 92.47% in 24 h. The key enzyme（s） involved in the initial biodegradation of monocrotophos in M-1 was shown to be constitutively expressed cytosolic proteins and showed the greatest activity at pH 8.0 and 25 ℃, with its Michaelis-Mentn＇ s constant （Km） and maximum degradation rate （Vmax） of 0.29μmol· mL^-1 and 682.12μmol· （min· mg）^- 1 respectively. This degrading enzyme（s） was sensitive to high temperature, but kept high activity under alkaline conditions.

关 键 词：久效磷 生物降解 PARACOCCUS sp. 酶促降解 

分 类 号：X172[环境科学与工程—环境科学]