耐盐好氧反硝化菌A-13菌株的分离鉴定及其反硝化特性

Isolation and characterization of the salt-tolerant aerobic denitrifying bacterial strain A-13

摘要:

摘要:【目的】筛选高效好氧脱氮的反硝化细菌，对菌株进行多项鉴定及条件优化，为后续富营养化人工湖水体治理提供理论依据。【方法】利用反硝化培养基分离筛选好氧反硝化细菌，通过形态、生理生化、16S rRNA基因序列分析、周质硝酸还原酶亚基基因(napA)同源性分析进行菌株鉴定;通过反硝化培养基，对菌株生长及反硝化的最适pH、温度、碳源、溶解氧、接种量等进行了考察。【结果】从福州市闽侯县上街镇高岐村某排污口分离出1株耐盐高效好氧反硝化细菌A-13，多项鉴定表明该菌株为Pseudomonas stutzeri，与Pseudomonas stutzeri DSM 50283亲缘关系最近。菌株生长及反硝化的最适pH为6.5，最适温度为33℃，最适碳源为丁二酸钠，最适摇床转速为150 r/min，最适接种量为5%。在此条件下，最大可去除NO3－浓度约为1900 mg/L。该菌能够在高盐培养基(10% NaCl)中良好生长。对人工废水的净化效果表明，该菌具有一定的工程应用价 值。【结论】分离所得好氧反硝化细菌为Pseudomonas stutzeri，将其命名为P. stutzeri YHA-13。具备高耐盐性的好氧反硝化功能的P. stutzeri未见报道。这对含盐废水/富营养化水体的工程应用有一定的潜在价值。

Abstract:

Abstract:［Objective］This study is aimed to isolate and identify an aerobic denitrifying bacterium with high ability for nitrogen removing，and optimize its growing and denitrifying conditions to obtain the theory basis for controlling the eutrophic artificial lake． ［Methods］Aerobic denitrifying bacterium strain A-13 was screened by denitrifying medium．Strain identification was carried out through morphological，biochemical and physiological characteristics，16S rRNA gene and periplasm nitrate reductase gene analysis．The optimal pH，temperature，carbon source，dissolved oxygen (DO)，inoculum ratio were tested as well． ［Results］Strain A-13 isolated from a drain outlet located in Gaoqi village，Shangjie town，Minhou county，Fuzhou，China，was a member of Pseudomonas stutzeri and its DNA sequence was most closely related to Pseudomonas stutzeri DSM 50283．The optimal conditions for its growth and denitrification were followed as: pH 6.5，33℃，150 r/min，5% inoculum rate and the best carbon source was sodium succinate． Under these conditions，the maximum removal capacity for NO－3 was approximately 1900 mg/L．The strain could grow well in the medium with high salinity(10%) and could also use NO－2 and NH+4-H as the sole nitrogen source．［Conclusion］The isolated P．stutzeri，A-13 is a potential strain to treat wastewater with high salinity and/or eutrophication．