大连海区海藻和无脊椎动物附生细菌对养殖网笼污损细菌的拮抗活性

Antibacterial activities of epiphytic bacteria from the surfaces of seaweeds and invertebrates against fouling bacteria isolated from a net cage in coastal sea in Dalian

以从养殖网笼上分离的6株污损细菌为指示菌,采用双层琼脂扩散法对从藻类表面分离出的192株和从无脊椎动物表面分离出的127株附生细菌进行筛选,从中获得有拮抗活性的菌株分别为60株和49株,占其测试菌株的31.3%和38.6%。从不同海藻和无脊椎动物附生细菌中可以筛选出不同得率的活性菌株,其抗菌谱和活性强度各不相同,将抗菌谱和活性强度两个参数结合,设置活性指数Index(I),经计算可知,P31、HE426和AU4111的活性最高,其I值(≥2.00)最大。研究结果表明,海藻和无脊椎动物附生细菌可能帮助宿主阻止污损细菌等污损生物的附着。

192 strains of bacteria isolated from the surfaces of seaweeds and 127 strains of bacteria isolated from the surfaces of invertebrates were tested for antibacterial activity by the indictors of six strains of fouling bacteria isolated from a nct cage. 60 and 49 bacterial isolates, accounting for 31.3% and 38.6% of the total tested bacteria, showed the activities against at least one target fouling bacterial strain. Different percentages of bioactive bacteria were screened from various seaweeds and invertebrates. The bacteria with bioactivity had different antibacterial spectra and strengths by the combined index. The antibacterial activities of strains P31, HF426 and AU4111 （their Index≥2.00） were found to be the highest among strains tested on the basis of the index calculated. These results indicated that the seaweeds -associated and invertebrates-associated bacteria may help the host against colonization of fouling bacteria.