中国南海一株固氮类芽孢杆菌的筛选和分离鉴定

摘要

为了解中国南海海洋自生固氮菌的种类，作者对采集的南海海底淤泥样品进行了固氮微生物的分离、筛选及鉴定。经过土样沸水加热处理，无氮培养基平板初筛后，对分离获得的细菌固氮酶结构基因 nifH 进行扩增，并对其固氮酶活性进行检测，最终获得一株能够产芽孢的固氮细菌。对该菌株进行生理生化性状测定、16S rDNA序列分析(GenBank登录号 KJ627376)，并基于nifH、16S rDNA系统进化树分析，确定该菌为一株固氮类芽孢菌(Paenibacillus sp.) NH-1。本研究表明固氮类芽孢杆菌在海洋中确有分布，海洋自生固氮菌的多样性远远超出人们之前的认识。%To understand the diazotrophic microorganisms from the South China Sea, the nitrogen fixation bacteria were isolated from sediments samples, screened and identified. By prescreening in N-free plate after boiling the samples, the nifH gene of isolate NH-1 was analyzed by PCR amplification and the nitrogenase activity was tested by acetylene reduction assay. The straln NH-1 was found to belong to the genus Paenibacillus based on morpho-logical characteristics, physiological and chemical characteristics and 16S rDNA sequencing analysis (GenBank accession No. KJ627376). The isolate NH-1 was identified as Paenibacillus sp. NH-1. This study provides evidence that marine nitrogen-fixing microorganisms are far more diverse than currently recognized.