1株好氧反硝化菌的分离鉴定和反硝化特性研究

Identification and Denitrification Characteristics of an Aerobic Denitirfier

从沈阳北部污水处理厂曝气池的回流污泥中驯化分离得到16株有好氧反硝化能力的菌株,并最终筛选得到1株好氧反硝化能力较强的菌株N6。菌株N6的革兰氏染色为阴性、无芽孢;经16Sr DNA序列分析,鉴定其为假单胞菌(Pseudomonas sp).。反硝化特性实验表明:菌株反硝化的最佳温度是30℃、最适pH值为7、最佳C/N比为15∶1;碳源的种类对菌株的反硝化效果影响很大,菌株N6对丁二酸钠和乙酸钠等小分子碳源的利用相对高于对葡萄糖、蔗糖等大分子碳源的利用,菌株反硝化的最适碳源是丁二酸钠。在最佳降解条件下,菌株24 h对硝酸盐的降解率达98%,并且没有亚硝酸盐的积累。

16 strains of aerobic bacteria with denitrification ability were cultured and isolated from activated sludge of a WWTP in Shenyang and further isolation led to an effective aerobic denitrification strain N6,which was Gram-stain negative,non-spore and identified as Pseudomonas sp.according to 16S rDNA.Results of aerobic denitrification characteristics showed that the at optimal temperature 15 ℃,pH 7 and C/N 15∶1,and that type of carbon source had a great impact on de-nitrification.Besides,N6’s utilization of small molecular carbon source such as sodium succinate and sodium acetate was relatively higher than large molecules such as glucose and saccharose;in addition,the best carbon source for N6 was sodium succinate.Under optimal degradation condition,the degradation rate of nitrates was more than 98% in 24 hours without the accumulation of nitrite.