1株反硝化细菌的筛选鉴定及其基于响应面法的脱氮条件优化

Screening of an Aerobic Denitrifying Strain and Its Denitrification Conditions Optimization Using Response Surface Methodology

从污水处理厂采集的污泥样品中分离、筛选出1株具有较高好氧反硝化性能的菌株,命名为X_(3)。通过菌落形态特征、染色特征观察以及16S rDNA分子鉴定,初步确定该菌株为赤红球菌(Rhodococcus ruber)。为了明确该菌株的脱氮特性,通过单因素试验,确定了菌株的最佳碳源为葡萄糖,最佳C/N比为10。利用响应面分析方法考察温度、pH以及转速三个因素相互作用对菌株脱氮能力的影响。研究结果表明,菌株X_(3)在32.24℃,pH为6.65,180.79 r/min为最佳培养条件。最佳条件下培养48 h后,NO_(3)^(-)-N去除率可达96.99%,同时没有NO_(2)^(-)-N的产生。筛选获得的好氧反硝化菌株X_(3)可以作为生物脱氮菌剂开发和相关脱氮机制研究的候选菌株。

A strain with high aerobic denitrifying activity was isolated from the sewage treatment plant and was named X_(3).Through the observation of colony morphological characteristics,staining characteristics and 16S rDNA sequence homology comparison,X_(3) was identified as Rhodococcus ruber.To clarify the denitrification characteristics of X_(3),through the single factor test,the optimal carbon source for this strain was glucose and the optimal C/N ratio was 10.The effect of the interaction of three factors,temperature,pH and rotational speed on the denitrification ability of the strain was investigated by using response surface methodology.It was analyzed that strain X_(3) showed a maximum NO_(3)^(-)-N removal of 96.99%after 48 h incubation at optimal culture conditions of 32.24℃,pH=6.65,180.79 r/min.The results showed that aerobic denitrification strain X_(3) could be used as a candidate strain for the development of biological denitrification agents and the study of denitrification mechanisms.