1株高产琼脂糖酶海洋弧菌的分离与酶活性的测定

Isolation and Enzyme Activity Assay of An Agarase-producing Vibrio sp. Strain

琼脂糖酶是一类糖苷水解酶,能够催化琼脂多糖分解为低聚糖,在食品工业、化妆品及生物医学领域等具有重要的应用价值。笔者从华南沿海海水样品中分离出1株海洋弧菌HN897,选用以琼脂为唯一碳源的培养基并通过透明圈筛选法筛选,确定此海洋弧菌为1株具有琼脂酶高产能力的细菌。16S r RNA基因序列分析结果显示,该菌株属于弧菌属Vibrio astriarenae。通过DNS-还原糖法对其在2种TSB和LB2培养液上清中的酶活性进行测定,测得粗酶液酶活力分别为0.366和0.413 U·m L-1,说明琼脂糖酶具有潜在开发利用价值。本研究结果可为后续开发研究及应用奠定基础。

Agarases are the enzymes which catalyze the hydrolysis of agar. They have wide applications in food industry, cosmetics, and medical fields since they produce oligosaccharides with remarkable enzyme activities. A Vibrio sp. strain, named HN897, was isolated from seawater samples in the South China coastal area using TCBS agar plate. This strain was identified as an agarase-producing bacterium by observation of clear zones around the colonies using agar as the sole carbon source. Phylogenetic analysis based on 16 S r RNA gene shows that the agar-degrading bacterium HN897 belongs to the member of the genus Vibrio and is close to Vibrio astriarenae.The agarase activity of the strain was determined by using reducing dinitrosalicylic acid method（DNS method）, and the agarase activities of the crude enzymes in the supernatant of HN897 culture of the TSB and LB mediums were0.366 U·m L-1 and 0.413 U·m L-1, respectively, indicating that this strain has potential applications in the production of agaro-oligosaccharide.