一株海洋好氧反硝化细菌的鉴定及其好氧反硝化特性  

Identification and characteristics of a marine aerobic denitrifying bacterium

作　　者：高喜燕[1] 刘鹰[2] 郑海燕[1] 刘缨[1] 刘志培[1] 

机构地区：[1]中国科学院微生物研究所,北京100101 [2]中国科学院海洋研究所,青岛266071

出　　处：《微生物学报》2010年第9期1164-1171,共8页Acta Microbiologica Sinica

基　　金：国家“863计划”(2006AA100305)~~

摘　　要：【目的】从处理海洋养殖循环水的生物滤器生物膜中分离到1株具有好氧反硝化活性的细菌（菌株2-8）,并进一步研究了该菌的分类地位及反硝化特性。【方法】采用16S rRNA基因序列分析对菌株进行初步鉴定,采用好氧培养技术,探讨了碳源种类、起始pH、NaCl浓度、C/N、温度和摇床转速对菌株2-8好氧反硝化活性的影响。【结果】该菌株的16S rRNA基因序列与Pseudomonas segetis FR1439T（AY770691）的相似性最高,达到99.9%,因此初步鉴定菌株2-8属于假单胞菌属（Pseudomonas sp.2-8）。碳源类型和C/N对其好氧反硝化作用的影响最为显著,以柠檬酸钠为唯一碳源,C/N为15时脱氮效率最高,低C/N导致亚硝酸盐的积累;其好氧反硝化的最适温度和pH分别为30℃和7.5;菌株2-8在摇床转速为160r/min下脱氮效果最好;NaCl浓度对其反硝化活性的影响不明显。【结论】在初始硝酸氮浓度为140mg/L,以柠檬酸钠为唯一碳源、C/N为15、pH为7.5、NaCl浓度为30g/L,30℃以及160r/min摇床培养的条件下,菌株2-8在48h内脱氮率可达92%且无亚硝酸盐积累。[Objective]An aerobic denitrifying bacterium,strain 2-8,was isolated from a biological aerated filter in a recirculating marine aquaculture system,phylogeny and characteristics of the strain was further studied.[Methods] Sequence of the 16S rRNA gene was analyzed and the factors affect the denitrifying ability of strain 2-8 were investigated,including carbon source,C/N ratio,initial pH,NaCl concentration,temperature and shaker speed.[Results]Strain 2-8 was identified as Pseudomonas sp.based on the analysis of its 16S rRNA gene sequence which showed highest similarity（99.9%） to Pseudomonas segetis FR1439T（AY770691）.The results indicated that carbon source and C/N ratio exhibited significant influences on aerobic denitrifying capacity of strain 2-8.Strain 2-8 could grow a little on acetate,succinate and citrate as sole carbon source,and the removal rates of NO 3--N at 140 mg/L were higher than 65% despite of the accumulation of NO 2--N around 35 mg/L.It grew quite well on glucose as sole carbon source,however,the removal rate of nitrate was not so high as on other carbon source.The optimum C/N ratio was 15,as lower C/N ratios may lead to nitrite accumulation.The optimum temperature and pH for its aerobic denitrification were 30℃ and 7.5,respectively.Strain 2-8 could grow and exhibit aerobic denitrifying ability at a wide range of NaCl concentrations（0-30 g/L）.The highest nitrogen removal appeared under the condition of 160 r/min shaking culture.[Conclusion]When cultured in the conditions of NO 3--N at 140 mg/L,sodium citrate as sole carbon source,C/N ratio at 15,pH 7.5,NaCl at 30g/L,30℃ and 160 r/min of the shaker,strain 2-8 removed up to 92% of the nitrogen within 48 hours,and no nitrite accumulation.

关 键 词：海洋环境 氮素去除 生物脱氮 好氧反硝化菌 

分 类 号：X703[环境科学与工程—环境工程]