高效抑藻放线菌的筛选和活性

Isolation of a strong antialgal Streptomyces strain and study on its antialgal activities

为了寻找抑杀微囊藻的放线菌,对江苏海洋滩涂土壤中分离到的放线菌进行了筛选,获得了1株对微囊藻有强烈抑杀作用的菌株YC0412。进一步实验表明这株放线菌对其它富营养水体中常见藻类,小球藻、栅藻、鱼腥藻和集胞藻都有不同的抑杀作用,藻的液体培养物中分别加入1/10体积的YC0412发酵液,培养3d后生长分别被抑制了32.4%,12.46%,32.9%,82.19%和32.57%,说明该菌的抑藻作用具有广谱性。通过对YC0412形态学特征、生理生化特性、细胞壁化学组分以及16SrDNA序列进行分析,结果表明YC0412为1株灰霉素链霉菌(Streptomyces griseinus)。为了弄清杀藻活性物质的性质,对YC0412发酵液分别采用乙酸乙酯和氯仿进行了抽提,测定结果显示,乙酸乙酯提取物有很好的杀藻作用,说明其活性产物应该是一种弱极性脂溶性物质。

To find a anti-Microcystis microorganism as a biological control agent, we screened all actinomycetes isolated from soil samples of sea beach in Jiangsu Province, China. A strain YC0412 capable of strongly inhibiting the cyanobacteria Mierocystis aeruginosa PCC7806 was isolated. Growthes ofAnabaena sp. PCC7120, Synechoccocus sp. PCC6803, Chlorella ellipsoidea and Scenedesmus sp. were also inhibited by 32.4% , 12.46% , 32.9% , 82.19% and 32.57% respectively with 1/10 volume of YC0412 broth after 3 days . The data showed YC0412 had a wide host rang of antialgal activity. On the basis of morphological, physiological and biochemical characteristics, and 16S rDNA sequence, strain YC0412 was determined to be Streptomyces griseinus. To investigate the property of antialgal substance produced by YC0412, we extracted the culture broth of YC0412 with ethyl acetate or chloroform, and tested the anti-Microcystis activities of different fractions. The ethyl acetate extract fraction resulted in an stronger inhibition of Microcystis. That implied that the active substance should be a low polar and hydrophobic molecular.