虎杖内生放线菌的分离鉴定及抗菌活性

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

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.

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 actinomyeetes fermentation broth were deter- mined 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.