一株海洋拮抗菌的筛选与鉴定

通过平板分离、摇瓶发酵，从样品中分离到1株对枯草芽孢杆菌、藤黄八叠球菌、大肠杆菌等指示菌具有较强拮抗作用的菌株HY4，通过菌落形态、镜检、生理生化试验和对菌株16S rRNA基因序列遗传分析对菌株进行鉴定，发现该菌株跟芽孢杆菌属（Bacillus）的多数菌株序列有99%的相似性，将该菌株命名为芽孢杆菌HY4。当培养时间为48 h时，菌株的生物量达到最大值，OD600nm为2.49，此时菌株对枯草芽孢杆菌和藤黄八叠球菌的抑菌活性也达到最高，透明圈直径分别为1.38 cm和1.13 cm，当培养至60 h时，菌株对大肠杆菌的抑菌活性也达到最大，透明圈直径为1.13 cm，之后随着培养时间的延长，抑菌活性反而逐渐降低。

Screening and identification of a marine antagonistic bacterium

The strain HY4 which had antibacterial activity on Bacillus subtilis, Sarcina lutea, Escherichia coli was isolated from the samples through the plate separation, shake flask fermentation. The strain HY4 had 99% similarity to the most of Bacillus sequence and was identified as Bacillus HY4 by colony morphology, microscopy, physiological and biochemical tests and 16S rRNA gene sequence. When culture time was 48 h, the biomass of strain reached the maximum and OD600nm was 2.49. At the moment, the antibacterial activity of the strain on B. subtilis and S. lutea also reached the maximum, and the diameter of transparent circle were 1.38 cm and 1.13 cm, respectively. When culture time was 60 h, the antibacterial activity of the strain on E. coli reached the maximum, and the diameter of transparent circle was 1.13 cm. Then with the prolongation of culture time, the antibacterial activity reduced gradually.