黄鳝肠道益生菌HY-136的鉴定与系统发育分析

对分离自健康黄鳝肠道118株菌进行点种法病原菌拮抗试验,结合产酶能力分析试验结果,得到了对病原菌拮抗作用显著和产酶能力较强的拟选菌株HY-136.通过对该菌株进行形态观察,常规生理生化鉴定和应用API 50 CHB鉴定盒鉴定,结果表明该菌与枯草芽孢杆菌属的形态及生理生化特征相似;进一步利用PCR技术对该菌株16S rRNA序列作测定与分析,序列结果在GenBank中进行Blast同源序列检索,并用Mage4.0软件与芽孢杆菌属的其它菌种进行序列分析比对,结果表明其与已报道的枯草芽孢杆菌序列(登录号为EU346662)具有99.8%的同源性,且二者在所构建的系统发育树上处于同一个分支.确定菌株HY-136为枯草芽孢杆菌(Bacillus subtilis).

Phylogenetic Analysis and Identification of Probiotics HY-136 from Ricefieid Eel(Monopterus Albus)Intestine

One hundred and eighteen bacterial strains isolated from healthy ricefield eel(Monopterus albus)intestine were used for screening probiotics.The results of antagonistic disease bacteria by dot inoculating and the amount of extra-cellular amylase produced showed that HY-136 could strongly inhibit pathogenic bacteriums and produced more amylase.According to its morphological,physiological and biochemical characteristics,and the results detected by API 50 CHB system,we found that some characteristics of strain HY-136 were similar to Bacillus subtilis.Sequence analysis of 16S rRNA showed that strain HY-136 shared 99.8%homology with published sequence of Bacillus subtilis(accession number:EU346662).In the phylogenetic tree,both of them were on the same branch.which showed that strain HY-136 was closely related with Bacillus subtilis.Therefore,strain HY-136 was identified as Bacillus subtilis.