秦巴山区三尖杉根际土壤放线菌的分离、筛选及活性菌株的鉴定

Isolation,screening and identification of active actinomycete from Cephalotaxus fortunei rhizosphere soil in Qinba Mountains

采用选择性分离方法从秦巴山区三尖杉植物根际土样中分离得到放线菌35株,以白色念珠菌(Candida albicans)、大肠杆菌(Escherichia coli)、枯草芽孢杆菌(Bacillus subtilis)、金黄色葡萄球菌(Staphylococcus aureus)、沙门氏杆菌(Salmonella typhl)为靶标菌,采用滤纸片扩散法研究三尖杉根际土壤放线菌发酵液的抑菌活性。结果表明,16株放线菌表现出至少对一种靶标菌有抗性,占总分离菌株的45.7%,其中,菌株CF003对所有靶标菌均具有活性;经形态学和16S rRNA基因序列鉴定,这16株放线菌分属于链霉菌属(Streptomyces)和小单孢菌属(Micromonospora)。

35 strains of actinomycetes isolated from Cephalotaxus fortunei rhizosphere soil in Qinba Mountains,China,were studied in this paper. Phylogenetic analysis based on 16 S rRNA gene sequences indicated that the 16 strains belong to small group of actinobacterial genera including Streptomyces and Micromonospora. Candida albicans,Escherichia coli,Bacillus subtilis,Staphylococcus aureus,Salmonella typhl were selected as indicator bacteria when the antimicrobial activities of these actinomycetes were tested through antimicrobial experiments in the exterior body. The result showed that 16 strains（ 45. 7%） exhibited activity against at least one target strain,and the CF003 strain has strong inhibition to all target strains.