The phylogeny and denitrifying characteristics of a newly isolated strain Y-9 were clarified. The psychrotrophic and aerobic nitrite-bacterium, strain Y-9, was successfully identified based on the analysis of its morphology, phospholipid fatty acid and 16SrRNA gene sequence analysis. Additionally, factors such as temperature, shaking speed, pH, incubation quantity, carbon source and nitrite content affecting the aerobic denitrification ability of Y-9 strain were investigated. Results showed that the Y-9 was identified asPseudomonas putida which combined with three methods to identify the newly isolated strain could offer taxonomic assignment with higher confidence. A psychrotrophic and aerobic nitrite-denitrifying strainPseudomonas putida Y-9 exhibited high removal efficiency of nitrite and total nitrogen. The nitrite and total nitrogen removal efficiency was up to 100% and 77.13% with 100 r/min shaking speed at 15℃. The optimal conditions of culture were determined, including temperature 15℃, shaking speed 100 r/min, pH 7, inoculated quantity 1 mL(OD600, 0.5)bacterial suspension within 100 mL denitrification broth medium and carbon source sodium citrate. Low concentration of nitrite nitrogen could be beneficial for the strain Y-9 to perform denitrification at 15℃. Strain Y-9 was a psychrotrophic nitrite-denitrifying bacterium with optimum temperature of 15℃ and strain Y-9 could tolerate high concentration of nitrite nitrogen, which has a great potential for removing nitrogen from aquaculture water environment, especially in the cold circumstance.%旨在对获得的具有耐冷高效去除亚硝酸盐氮和总氮的好氧反硝化细菌进行分类地位及除氮特性研究。结合形态学观察、特异性磷脂脂肪酸检测和16S rRNA基因序列分析，对实验室新分离获得的Y-9菌株进行鉴定，在此基础上，研究了温度、转速、pH、接种量、碳源和亚硝酸盐氮浓度等不同条件对该菌脱氮能力的影响。结果显示，菌株Y-9属于恶臭假单胞菌（Pseudomonas putida），还原亚硝酸盐氮的最适温度为15℃，最佳溶解氧水平对应转速为100 r/min，在该溶解氧水平下15℃、48 h内对亚硝酸盐氮和总氮的去除率高达100%和77.13%，最佳pH为7，100 mL反硝化培养基中最适接种量为1 mL OD600为0.5的菌悬液，碳源为柠檬酸钠，适合治理低浓度的亚硝酸盐氮污染水体，但对高浓度的亚硝酸盐氮具有一定耐受性。Y-9为一株耐冷反硝化细菌，在亚硝酸盐污染的养殖水体，尤其是冷水鱼类养殖水体中具有较大的应用潜力。
展开▼
