低温硝基苯降解菌的筛选及降解特性研究

Isolation of a Bacterial Strain Capable of Nitrobenzene-Degradation at Low Temperature and the Biodegradation Characteristics

从被硝基苯污染的某河流底泥中分离到能在低温下生长并能以硝基苯为唯-碳源的7株细菌，其中菌株NBI在温度从2．5—35℃范围内时都可以生长并矿化20mg／L的硝基苯，最适宜的生长温度为25℃左右；当培养温度为5℃时，该菌株在pH为6—9范围内可以快速降解20mg／L硝基苯，偏碱性的条件比酸性条件更适合其生长；不超过100mg／L的硝基苯可以被该细菌完全降解．通过生理生化反应特性、菌体形态以及16SrDNA序列测定结果，确定NBI为恶臭假单胞菌（Pseudomonas putida）．不同温度条件，特别是低温下该菌株对硝基苯的快速降解特性为低温环境硝基苯污染的生物修复提供了可能．

Seven bacterial strains that can degrade nitrobenzene at low temperature were isolated from the sediments of a nitrobenzene polluted river. One of the strains, NB1, can mineralize 20 mg/L nitrobenzene completely under the temperature range from 2.5 ℃ to 35 ℃ with an optimum temperature of 25 ℃. At 5 ℃, the strain can grow and degrade 20 mg/L nitrobenzene under pH 6 - 9. As long as the concentration of nitrobenzene was not higher than 100 mg/L, it can be degraded by the strain successfully. The strain was identified as Pseudomonas putida according to its morphology, biochemical properties and 16S rDNA sequence analysis. The growth and nitrobenzene degradation character of the strain at different temperature, especially at low temperature, shows the potential for the bioremediation of nitrobenzene contaminated environment.