中国南海一株固氮类芽孢杆菌的筛选和分离鉴定

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nif H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 r DNA序列分析(Gen Bank登录号KJ627376),并基于nif H、16S r DNA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。

Isolation and identification of a Paenibacillus sp. Producing nitrogenase activity from South China Sea

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 strain NH-1 was found to belong to the genus Paenibacillus based on morphological 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.