一株产琼胶酶海洋细菌的分离与鉴定

Isolation and identification of a bacterial strain producing agarase from sea water

为获得琼胶酶活性高产菌株,对采集的海水样品进行了产酶微生物的分离、筛选和鉴定。经过平板培养预筛和两次摇瓶培养筛选,从浙江省舟山市普陀区近海海水样品中分离到一株琼胶酶产生菌 G-5,该菌株液体培养产酶活力可达到413.8 U/mL。G-5菌株的菌落呈乳白色、半透明、表面湿润；菌体革兰氏染色阴性,大小0.58-0.69μm×1.50-2.26μm；光学显微镜下呈短杆状,略有弧形。G-5菌株的16S rDNA序列与NCBI数据库中15个弧菌属（Vibrio）菌株的16S rDNA有98%的同源性,可以确定G-5菌株是一株弧菌（Vibrio sp.）。

To obtain microbes for producing high activity agarase, a series of bacterial strains in sea water were isolated, screened and identified. By prescreening in plate cultivation and twice screening in liquid cultivation, a strain designated as G-5 was isolated from sea water that was taken from Zhoushan coastal areas in Zhejiang Prov-ince. The activity of agarase produced by G-5 could reach 413.8 U/mL. The colony of G-5 was milky white and semitransparent with a wet surface. The cell of G-5 was Gram negative and rod-shaped with a size of 0.58-0.69μm×1.50-2.26μm. The 16S rDNA sequence of G-5 was 98%homologous to 15 strains of Vibrio species in the da-tabase of NCBI. It could be concluded that the strain G-5 was a Vibrio species.