一株反硝化细菌的鉴定、功能基因检测及其反硝化特性

采用富集培养和BTB(溴百里酚蓝)平板法从活性污泥中分离出一株高效的反硝化菌ADH1。结合16S rDNA系统发育分析结果和生理生化反应,将该菌鉴定为施氏假单胞菌(Pseudomonas stutzeri),经检测该菌株中存在反硝化功能基因nirS和nosZ,并由此推知其具备完整的反硝化酶系。通过这两种功能基因的系统发育分析,从另一角度证实了菌株ADH1属于Pseudomonas sp.。反硝化特性研究结果表明,在静置条件下,该菌在16 h内对NO3--N的转化率达到96.1%,其中84.7%的NO3--N完全经反硝化作用从培养液中去除,剩余的则被菌体同化吸收;而在150 r/min的振荡培养条件下,该菌在10 h对NO3--N的转化率高达97.8%,TN去除率也超过40%。研究结果表明菌株ADH1可能是一株有着良好应用前景的高效好氧反硝化细菌。

Study on a Denitrifier Strain:Its Identification,Functional Genes Detection and Denitrification Characteristics

A high efficient strain of denitrifier ADH1 was isolated from activated sludge by enrichment culture and RTB plates,which was identified as Pseudomonas stutzeri through phylogenetic analysis based on its 16S rDNA sequence and biochemical characteristics,and in which two functional genes(nirS and nosZ)relating to denitrification were found implying the existence of a complete denitrifying enzyme system.The phylogenetic analysis also proved the strain of denitrifier ADH1 belonged to Pseudomonas sp.Findings of its denitrification showed that the conversion rate of nitrate went up 96.1% in 16 h under static cultivation and more than 84.7% on nitrate was totally removed from the cultural medium;on the other hand,under rocking cultivation condition(150 r/min)the conversion rate could reach 97.8% and a total nitrogen removal of 40% within 10 h.