昌江石斛内生抗菌活性菌株筛选与鉴定

Screening and identification of endophytic antimicrobial strains from Dendrobium changjiangense

采用组织块分离法和划线分离法,从昌江石斛(Dendrobium changjiangense)植株体内分离得到内生细菌10株,以大肠埃希菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)和白假丝酵母菌(Candida albicans)3株供试指示菌,采用琼脂平板法对分离的昌江石斛内生细菌进行抗菌活性的研究。结果表明,昌江石斛分离到的内生细菌中根部最多,茎部次之,叶部最少,昌江石斛所分离出的10株内生细菌中,有2株对至少1种供试菌有一定的抑菌作用,占总分离菌株的20%,其中C-06菌株对3种指示菌均具有抑菌作用,有1株细菌C-05分别对2种指示菌有抑菌作用。通过细菌16S rRNA基因序列分析,活性菌株分布在芽孢杆菌属、类芽孢杆菌属。昌江石斛含有丰富的内生菌资源,部分内生菌具有代谢抑菌的特性,可作为新型药物的筛选源,为临床疾病的治疗提供可参考的途径。

Ten endophytic bacteria were isolated from Dendrobium changjiangense by tissue block method and streak method,and three indicator bacteria including Escherichia coli,Staphylococcus aureus and Candida albicans were used to study the antimicrobial activity of endophytic bacteria isolated from Dendrobium changjiangense by agar plate method.The results showed that among the 10 endophytic bacteria isolated from Dendrobium changjiangensis,the root was the most,followed by the stem,and the leaf was the least.Among the 10 endophytic bacteria isolated from Dendrobium changjiangensis,two strains had inhibitory effects on at least one test bac⁃terium,accounting for 20%of the total isolated strains.Among them,C-06 strain had inhibitory effects on the three indicator bacte⁃ria,and one strain C-05 had inhibitory effects on the two indicator bacteria,respectively.Through the analysis of bacterial 16S rRNA gene sequence,the active strains were distributed in Bacillus and Bacillus-like.Dendrobium changjiangense is rich in endophytic bac⁃teria resources.Some endophytic bacteria have the characteristics of metabolic inhibition,which can be used as a screening source of new drugs and provide a reference for the treatment of clinical diseases.