好氧反硝化细菌YX-6特性及鉴定分析  

Characteristics of aerobic denitrifying strain YX-6 and identification

作　　者：安健[1,2] 宋增福[1] 杨先乐[1] 胡鲲[1] 路怀灯 佘林荣 

机构地区：[1]上海海洋大学水产与生命学院,国家水生动物病原库,上海201306 [2]扬州绿科生物技术有限公司,江苏扬州225600 [3]广东海富药业有限公司,广东潮州515700

出　　处：《中国水产科学》2010年第3期561-569,共9页Journal of Fishery Sciences of China

基　　金：国家公益性行业专项(nyhyzx07-042);国家公益性行业专项(NYCYTX-49-17);农业部行业专项(200803013)

摘　　要：从对虾池塘筛选得到1株高效的好氧反硝化细菌,命名为YX-6。对该菌生长及反硝化性能间的关系进行研究;同时研究了不同温度、pH、盐度及碳源对该菌生长及反硝化性能的影响。结果表明,该菌反硝化作用主要发生在对数生长期,可将亚硝酸盐氮由10mg/L降至0;该菌最适生长及反硝化温度为30℃;pH值范围为7～9时最适于该菌生长及反硝化性能的发挥。该菌最适盐度范围为0～15;丁二酸钠、乙酸钠为该菌生长及反硝化的最适碳源。通过对YX-6菌株生理生化及16SrRNA分子鉴定,初步鉴定为凝结芽孢杆菌(Bacillus coagulans)。对该菌株亚硝酸还原酶基因进行序列分析,结果表明,该菌含有亚硝酸还原酶nirS基因。Nitrite is a matter of great concern for aquaculture since the excessive amount of nitrite poisons the aquatic animals,induces diseases outbreak and results in huge economic losses.This problem becomes more and more serious in intensive cultivation mode.Obviously,the conventional theory to remove nitrogen is based on the principle that denitrification is restricted to anoxic condition.It is not appropriate for aquaculture,because there is adequate oxygen in the culture water which is essential to aquatic animals.Although some probiotics are used in the aquaculture to improve the water quality in practice,their work mechanisms are described to reduce nitrite concentration indirectly by decomposing the organic matter.Probably the aerobic denitrifying microorganisms offer the suitable way to resolve this contradiction.In the present experiment,the aerobic denitrification of strain YX-6 screened from shrimp ponds was investigated under different temperature,pH,salinity and carbon sources.The results indicated that strainYX-6 removed the nitrite nitrogen from 10 mg/L to 0 mg/L within its logarithmic phase; The optimum temperature range was 25-35℃and it even maintained higher denitrification efficiency（above 90%）at 40℃;Its denitrification efficiency was approximately 100%at pH 7-9,while the optimum salinity ranged from 0 to 15.The results also proved that sodium acetate and sodium succinate were the best carbon sources for the strain YX- 6.In this study,partial sequences of 16S rRNA of strain YX-6 were amplified and searched against GenBank using the Advanced BLAST similarity search option accessible from the homepage at the National Center for Biotechnology Information（http：//www.ncbi.nlm.nih.gov/）.The MEGA 4.0 version（Arizona State University 2007）software was used to check alignment and construct the phylogenetic tree.According to the physiological and biochemical properties,and 16S rRNA sequencing and alignment,the YX-6 was identified as Bacillus coagulans primarily. Furthermore,the nitrite reduct

关 键 词：好氧反硝化 凝结芽孢杆菌 16SrRNA 亚硝酸还原酶基因 

分 类 号：S94[农业科学—水产养殖]