摘要:

Strain HG-7 was identified as Pseudomonas sp.through 16s rRNA gene sequence analysis.The aerobic denitrification ability of strain HG-7 was further proved by the existence of the napA and nirK genes.Further studies showed that the optimal carbon resources for strain HG-7 were sodium acetate and sodium succinate,the optimal C/N ratio was 6-10,and the suitable temperature was 26-30℃.At this condition,with an initial nitrate nitrogen of 100 mg/L,98% of nitrate could be removed in 48 hours and the amount of nitrite accumulation was very small.Moreover,with nitrite as the sole nitrogen source,100% of nitrite could be removed at lower nitrite concentration.But the nitrite nitrogen removal rate was about 40% when the nitrite concentration increased to 91.4 mg/L,indicating that high nitrite concentration was harmful for aerobic denitrification by strain HG-7.The strain HG-7 has great potential to be used for biological nitrogen removal,which was particularly significant for actual wastewater treatment processes.以筛选分离得到的好氧反硝化菌HG-7为研究对象,经过16S rRNA同源性分析,初步鉴定该菌株为假单胞菌属(Pseudomonas sp.)。对菌株HG-7反硝化功能基因的扩增结果表明,菌体HG-7内存在好氧反硝化功能基因napA和nirK,证实该细菌为好氧反硝化细菌。对菌株 的脱氮特性和影响因素的研究表明,以硝酸盐氮为氮源时,菌株的最适碳源为乙酸钠和丁二酸钠,最佳C/N比为6~10,最适宜的温度范围为26~30℃。在 上述条件下,菌株HG-7的好氧反硝化活性较高,48小时内对100 mg/L硝酸盐氮的去除率可达98%,且在反应过程中亚硝酸盐氮积累量较低。以亚硝酸氮为唯一氮源时,低浓度条件下可实现100%的氮素去除率;高浓度条 件下,脱氮速率则受到明显的抑制,对91.4 mg/L的亚硝酸盐氮氮去除率约为40%。因此,将该菌株应用于废水的脱氮处理,可实现氮素的有效去除,具有潜在的应用价值。

附注:

Times Cited: 22