中文摘要：

从某农药厂排污口的污泥中采样，经驯化富集后筛选到1株能高效降解毒死蜱的细菌XZ-3，经过对其形态、生理生化特征及16SrDNA的分析，鉴定该菌株为节杆菌属（Arthrobacter sp.）．测定了不同碳源、pH、温度及毒死蜱浓度对细菌降解能力和生长量的影响，以培养液在波长400nm下的光密度值表示细菌生长量，液体介质中毒死蜱的提取采用漩涡振荡提取法，提取溶剂为石油醚，毒死蜱的测定采用紫外分光光度法．结果表明，该菌株24h内对100mg·L^-1毒死蜱的降解率高达86．8％；在外加碳源浓度为0．3％时降解率最大；细菌的生长量随着外加碳源浓度的升高而增加；pH在偏酸和偏碱性的条件下降解率较大，pH9．0时达到最大，细菌的生长量在pH8．0-10．0偏碱性的条件下较大；在毒死蜱浓度为100mg·L^-1时降解率最大，该菌具有较强的抗药性，当毒死蜱浓度达到1000mg·L^-1时仍能生长，细菌的生长量在800mg·L“时达到最大，绝对去除量随毒死蜱浓度的提高而增加；细菌的生长和降解需要适宜的温度，30℃培养时，降解率和生长量最大．本研究提出了细菌XZ-3生长和降解毒死蜱的最佳培养条件，可为农药污染治理及生产污水处理提供理论依据．

英文摘要：

A strain of bacterium XZ-3 capable of highly degrading chlorpyrifos was screened from the soil sample collected from a pesticide plant after taming and enrichment. Based on analysis of phenotype, physiological and biochemical characters and 16S rDNA, XZ-3 was identified as Arthrobacter sp.. The effects of carbon source, pH, temperature and chlorpyrifos concentration on degradation were determined. The growth of bacteria in culture media were measured by visible absorption spectrophotometry under 400 nm. The residual chlorpyrifos in culture media was extracted with an equal volume of petroleum ether, and then determined by ultra-violet spectrophotometry. The results showed that the degradation rate of chlorpyrifos by XZ-3 was 86.8 % in 24 h. The biodegradation rates were the highest when the additional carbon source was 0.3% , pH value was 9, chlorpyrifos concentration was 100 mg· L^-1, and cultivated temperature was 30℃ . The growth of bacteria increased with carbon source concentration, and was higher with pH from 8.0 to 10.0, and the highest when temperature was 30℃, and chlorpyrifos concentration was 800 mg·L^-1. The strain could survive when chlorpyrifos concentration was 1 000 mg· L^-1 and the removed amount of chlorpyrifos increased with chlorpyrifos concentration. The optimal conditions were proposed, which could provide theoretic basis for prevention and control of pesticides pollution.