三株红树林来源链霉菌的鉴定及抗菌活性研究

Identification and antibacterial activity of three mangrove-derived Streptomyces

目的 研究及鉴定广西茅尾海红树林植物根围淤泥中的3株链霉菌(K57M、K51M、K131M)及其抗菌活性。方法在4种培养基上分离放线菌,采用ISP2培养基进行菌株纯化;通过PCR扩增和测序,获得菌株16S rRNA基因序列,并进入数据库比对;采用邻接法构建系统发育树,并进行同源性分析,以此来研究放线菌的多样性和新颖性;牛津杯法开展3株菌株的抗菌活性初筛,采取纸片扩散法对制备的E1-3、A1-3和M1-3共3类样品复筛抗菌活性。结果经16S rRNA基因序列比对分析发现,菌株K57M可能为潜在的新放线菌菌株。抗菌活性筛选结果表明,K57M、K51M、K131M这3株链霉菌对不同的药敏菌株具有较好的抗菌活性。结论来源于广西茅尾海红树林根围淤泥中的链霉菌具有较强的抗菌活性,为我们挖掘天然活性的抗生素类化合物提供了极大的可能性。

Aim To study and identify the antibacterial activity of three strains of Streptomyces (K57M, K51M, K131M) collected from the roots of mangrove rhizosphere in Maowei Sea, Guangxi.Methods Actinobacteria were isolated on four media and purified by ISP2 medium.The16S rRNA gene sequences of three actinobacteria strains were obtained by PCR amplification and sequencing.Sequences of16S rRNA gene obtained by PCR amplification were submitted to gene database for BLAST search.Phylogenetic tree was constructed by adjacency method, and homology analysis was carried out to study the diversity and novelty of actinobacteria.Three actinobacteria strains underwent primary screening using Oxford cup method, and the antimicrobial activity of the sample of E1-3, A1-3 and M1-3 received secondary screening using disk diffusion method.Results Sequence alignment analysis of16S rRNA gene revealed that strain K57M might be a potential new actinobacteria.The results of screening for antimicrobial activity showed that three strains of Streptomyces , K57M, K51M and K131M, had good antimicrobial activities against different drug-sensitive strains.Conclusions Streptomyces from rhizosphere in the roots of mangrove forests in Guangxi can produce strong antibacterial activities, which provides great possibilities to explore natural active antibiotics.