一株养殖水体中亚硝酸盐去除菌的鉴定及其去除条件

Identification and removal condition of a nitrite removing bacterium from aquaculture sediment

摘要:

【目的】从养殖污泥中分离筛选优良亚硝酸盐去除菌, 并对其去除条件进行研究。【方法】从养殖污泥中分离亚硝酸盐去除菌, 进一步通过测定比较分离菌株对亚硝酸盐的去除率, 筛选优良的亚硝酸盐去除菌, 通过API ID32GN细菌鉴定系统以及16S rDNA序列分析法对其进行鉴定, 采用单因子法研究其去除亚硝酸盐的条件。【结果】从养殖污泥中分离筛选了一株优良的亚硝酸盐去除菌AQ-3, 其对50 mg/L亚硝酸盐的去除率高达99.47%。菌株AQ-3被鉴定为鲍曼氏不动杆菌(Acinetobacter baumannii) (GenBank登录号: JF751054.1), 其16S rDNA序列与基因库中不动杆菌属菌株的16S rDNA序列有99%?100%的同源性, 而且与鲍曼氏不动杆菌KF714株(GenBank登录号: AB109775)的亲缘关系最近。菌株AQ-3去除亚硝酸盐的最适初始pH范围为7?9, 最佳碳源为乙酸钠和丁二酸钠, 而且随着初始菌浓度的不断增大, 菌株AQ-3对亚硝酸盐的去除率显著升高; 随着亚硝酸盐浓度的不断增大, 菌株AQ-3对亚硝酸盐的去除率逐渐降低。【结论】在丰富亚硝酸盐去除菌种质资源的同时, 为该菌在养殖水体中的实际应用提供了理论基础。

Abstract:

[Objective] The aim of the present study was to isolate and screen potential nitrite removal bacteria, and examined the nitrite removal conditions. [Methods] Nitrite removal bacteria were first isolated from the aquaculture sediment, and the potential nitrite removal isolate was further screened through the nitrite removal rate comparison, identified using API ID32GN bacterial identification system and 16S rDNA sequence analysis, and its nitrite removal conditions were studied using single factor method. [Results] A potential nitrite removal bacterium AQ-3 was isolated and screened from the aquaculture sediment, its removal rate to 50 mg/L nitrite was 99.47%. Strain AQ-3 was identified as Acinetobacter baumannii (GenBank accession number: JF751054.1). Its 16S rDNA sequence had homology of 99%?100% with those of Acinetobacter sp. strains submitted to GenBank, and showed the most close relative to Acinetobacter baumannii strain KF714 (GenBank accession number: AB109775). The optimum initial pH range for the nitrite removal of strain AQ-3 was from 7 to 9, and the optimum carbon sources for its nitrite removal were sodium acetate and sodium succinate. In addition, the nitrite removal rates of strain AQ-3 were gradually rising with the increase of its initial bacterial concentrations, and the nitrite removal rates were gradually reduced with the increase of nitrite content. [Conclusion] The present study enriched the resources of nitrite removal bacteria and provide scientific basis to the practical use of strain AQ-3 in aquaculture.