高盐条件下硝基苯降解菌的分离及降解特性

Isolation and degradation characteristics of nitrobenzene degradation bacterium under hypersaline conditions

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(Corynebacteriumsp.)。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150r/min。最佳培养条件下,当硝基苯初始质量浓度低于150mg/L时,菌株培养72h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。

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, physiologi- cal and biochemical characteristics, the strain N18 was identified as Corynebacterium sp. Results of nitrobenzene deg- radation 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.