虎杖内生放线菌的分离鉴定及抗菌活性

采集秦巴山区野生虎杖(Polygonurn cuspidatum),选取以海藻糖、葡萄糖、淀粉等为主要营养和能源的4种培养基,经分离纯化得到47株内生放线菌.经形态学鉴定并结合16S rDNA序列分析,将6株具有较强抑菌活性的菌株初步鉴定为链霉菌属(Streptomyces)2株,小单孢菌属(Micromonospora)2株,链孢囊菌属(Streptosporangium)2株;采用滤纸片法初步研究了内生放线菌发酵液的抑菌活性.结果表明,17株菌株具有不同程度的抗菌活性,占所有分离菌株的36.2%,其中6株具有较明显的抑菌活性,菌株PEA023对所有靶标菌均有较强的抑制作用,菌株PEA023和PEA032对铜绿假单胞菌具有拮抗活性.

Isolation, identification and antimicrobial activity of endophytic actinomycets from Polygonurn cuspidatum

The 47 strains were isolated from Polygonurn cuspidatum collected in Qinba mountain areas,selecting and taking 4 sorts of mediums that contained trehalose,glucose and starch as main nutrients and energy sources.The 6 strains with strong antibacterial activity were classified into 3 genera of Streptomyces(2 strains),Micromonospora(2 strains) and Streptosporangium(2 strains) by 16S rDNA sequence analysis and morphology.Antimicrobial activities of endophytic actinomycetes fermentation broth were determined with filter paper.The results showed that 17 strains performed different degrees of antimicrobial activity accounting for 36.2% of all strains and 6 of them with significantly higher antibacterial activity.The PEA023 strain had strong inhibition to all target strains.Only PEA023 and PEA032 strains had antagonist activity against the gram-negative of Pseudomonas aeruginosa.