一株红树林根际固氮菌的分离、鉴定以及固氮活性测定  

Isolation and characterization of a N_2-Fixing Bacterium from the mangrove rhizosphere and study on its nitrogen-fixing ability

作　　者：凌娟[1,2,3,4] 董俊德[1,3] 张燕英[1,3] 杨志浩[1,3] 王友绍[2] 

机构地区：[1]中国科学院海洋生物资源可持续利用重点实验室,广东广州510301 [2]中国科学院热带海洋环境动力学重点实验室,广东广州510301 [3]中国科学院海南热带海洋生物实验室,海南三亚572000 [4]中国科学院研究生院,北京100039

出　　处：《热带海洋学报》2010年第5期149-153,共5页Journal of Tropical Oceanography

基　　金：中国科学院知识创新项目(KSCX2-SW-132);中国科学院南海海洋研究所LMM-LAMB-LMB联合开放课题;国家自然科学基金(40776069;40676091);国家生态系统研究网络三亚站数据库与信息系统;中科院生态系统研究网络台站研究基金;海洋公益性行业科研专项经费项目(200705026);广东省科技计划项目(2004B60302004;NO.2005B60301032);重大基础研究前期研究专项(2005CCA04800);广东省海洋药物重点实验室开放课题

摘　　要：采用选择性无氮培养基从红树林根际土壤中分离出一株具有高效固氮活性的固氮细菌,通过形态学,生化鉴定,G+C摩尔分数含量和16S rRNA以及固氮基因nif H的序列分析,初步鉴定为短小芽孢杆菌Bacillus pumilus。其特征是该菌为革兰氏阳性,直杆状,固体培养基上形成圆形白色菌落(直径3-4mm),与短小芽孢杆菌标准菌株相比较,它们在碳源利用,水解以及生长温度盐度等方面具相似程度很高,G+C摩尔分数含量为44.6%,以16S rRNA为基础构建的系统进化树分析其与短小芽孢杆菌B.pumilus B402的进化距离最近,相似性为99.6%,利用乙炔还原法对其固氮活性进行测定,具有较高的固氮活性,为156.32nmol C2H4·H-1·mL-1。A bacterial strain H9 capable of nitrogen fixation was isolated from the mangrove rhizosphere using N-free medium.It was identified as Bacillus pumilus by type description,physiological and biochemical test,G＋C Mole fraction（%）,16S rRNA sequence analysis and the nif H sequence analysis.It was a gram-positive,straight-rodded bacterium,which forms white colony with diameter of 3-4 mm on the solid agar medium.Compared with the standard strain of the species B.pumilus,there were high similarity in the carbon source utility,hydrolysis and the optimal growth temperature and salinity.The G＋C content of the strain DNA was 44.6%.A phylogenetic tree was constructed by comparing validly published 16S rRNA sequences of the related strains in the Genebank,using the neighbor-joining method.It showed that the strain H9 and the strain B.pumilus B402 have the highest similarity,which is 99.6%.The measurement of nitrogen-fixing ability by acetylene reduction was 156.32 nmol C2H4·H-1·mL-1,indicating its high nitrogen-fixing ability.

关 键 词：红树林 固氮菌 16S RRNA NIFH 

分 类 号：Q178.531[生物学—水生生物学]