硝基苯好氧降解细菌的筛选和降解活性研究

Screening of Nitrobenzene Degrading Microorganism under Aerobic Conditions and Its Degrading Activities

以长期受硝基苯污染的土壤和某化工厂污水处理厂曝气池活性污泥、排污口底泥为混合菌源，采用硝基苯浓度梯度增加的好氧振荡瓶法进行降解菌的驯化与富集培养，分离和纯化出1株能以硝基苯为惟一碳源、氮源和能源的细菌，初步鉴定为芽孢杆菌属。该菌株降解的最适温度为30～35℃，pH值7．5～8.0，摇床速度为150r／min。硝基苯在营养盐液体培养基中的最高降解允许浓度为1000mg／L。菌株在硝基苯初始浓度为100mg／L的营养盐液体培养基中培养6d后，硝基苯被完全降解。降解过程中无苯胺的积累。降解动力学分析表明，在硝基苯浓度低于1000mg／L条件下降解过程为零级反应关系。

A strain identified as Bacillus using nitrobenzene （NB） as a sole source of carbon, nitrogen, and energy was isolated by incubating NB with mixture of soil sample contaminated with NB, activated sludge from chemical wastewater treatment plant. The optimum conditions for the degradation of bacteria on NB were pH 7.5 - 8.0, 30 - 35℃ and 150 r/min. The growth of bacteria was inhibited and NB degradation was slowed when NB concentration was more than 1 000 mg/L in salt subculture. NB was completely degraded by adding bacteria to salt subculture with 100 mg/L NB within 6 days. There was no accumulation of aniline in the process of degrading of NB. The degrading reaction was proved to be zero order in NB concentration less than 1 000 mg/L by the kinetic analyses of the degradation process.