高盐条件下硝基苯降解菌的分离及降解特性

在高盐条件下,从某制药厂曝气池的活性污泥中分离、筛选得到6株硝基苯高效降解菌,其中菌株N18在高盐条件下对硝基苯降解效率最高.经形态特征和生理生化特征分析,初步鉴定N18属于棒状杆菌属(Corynebacterium sp.).硝基苯降解试验表明,菌株最佳培养条件为30℃、培养基pH 7、摇床转速150 r/min.最佳培养条件下,当硝基苯初始质量浓度低于150 mg/L时,菌株培养72 h后硝基苯降解率达75％以上.当盐度为1％～3％时,盐度对硝基苯降解率的影响不明显,当盐度为10％时菌株生长微弱,因此N18属于中度耐盐细菌.

Isolation and degradation characteristics of nitrobenzene degradation bacterium under hypersaline conditions

Six high efficiency nitrobenzene degradation strains were isolated and screened from activated sludge of aeration tank in a pharmaceutical factory under the hypersaline conditions.Among the six degradation strains,N18 presented the best nitrobenzene biodegradation capability.According to the morphological characteristics,physiological and biochemical characteristics,the strain N18 was identified as Corynebacterium sp.Results of nitrobenzene degradation experiments showed that the optimal N18 culture conditions were 30 ℃,pH 7 and shaker rotary speed 150 r/min.When the initial nitrobenzene concentration was below 150 mg/L,the nitrobenzene degradation rate of N18 was higher than 75% after 72 h of cultivation.In addition,the influence of salinity on nitrobenzene degradation rate was not obvious when salinity ranged 1%-3%,while the strain could hardly grow when the salinity up to 10%,so N18 was belonged to medium salt-tolerance strain.