亚硝酸盐降解菌的分离鉴定及其降解特性

从活性污泥中分离得到一株能以亚硝酸盐为唯一氮源生长的异养硝化细菌53,根据其形态、生理生化特性以及16S rRNA基因序列相似性分析结果,将其初步鉴定为假单胞菌属(Pseudomonas sp.)。研究了亚硝酸盐的初始浓度、pH、温度、接种量4个影响因素对菌株53降解亚硝酸盐效果的影响,确定了最适降解条件。结果表明,该菌株在亚硝酸盐浓度10 mg/L、培养温度30℃、pH为8.0、接种量5%条件下,接种24 h后对亚硝酸盐的降解率达到94.8%以上。在亚硝酸盐质量浓度为5mg/L的10L污染水体模拟实验中,按1%的接种量接入53发酵菌液(A600nm≈0.4),在30℃的水温条件下经4 d,53菌株对亚硝酸的降解率可达96.52%,处理后水体中亚硝酸盐的含量能达到养殖水体标准。表明该菌株对污染水体中的亚硝酸盐具有较强的降解效果。

Isolation,Identification and Degradation Characteristics of Nitrite Degradation Bactercia

A Heterotrophic Nitrifier,designate 53,capable of utilizing nitrite as sole nitrogen source was isolated from the activated sludge.It was preliminarily identified as Pseudomonas sp.According to its morphological and biochemical characters,and similarity analysis of 16SrRNA gene sequence.The effect of initial concentration of nitrite,pH,temperature and inoculation amount on degradation efficiencies was studied.The optimal degrading conditions were: initial concentration of nitrite 10 mg/L,temperature of 30 ℃,pH 8.0,inoculation amount of 5%,under the optimal conditions,the degrading efficiency could reach more than 94.8% after 24 h.In simulation test of 10 L polluted water in which the concentration of nitrite is 5 mg/L,the degradation rate of 53 strain on the nitrite achieved at 96.52% for 4 d in 30 ℃ via adding 10 mL fermentation liquor(A600 nm≈0.4).After processing,the nitrite content can reach aquaculture standards.All of the tests above indicated that the strain can degrade the nitrite in polluted water efficiently.