杨树溃疡病生防菌株N6-34抗菌活性物质的分离纯化与结构鉴定

【背景】杨树溃疡病是一种主要由葡萄座腔菌引起的杨树枝干病害,危害严重。前期从杨树中分离到一株内生拮抗细菌N6-34,研究表明该菌株拮抗效果好,对多种植物病原菌均有较强的拮抗作用。【目的】对拮抗细菌N6-34产生的抗菌活性物质进行分离纯化,并鉴定了活性物质组分的结构。【方法】通过硫酸铵盐析、甲醇抽提、分子筛、高效液相色谱等方法分离纯化N6-34菌株的抗菌活性物质,并对其进行结构鉴定。【结果】N6-34菌株发酵液经多步分离纯化,共获得14个组分,其中有13个组分具有抗菌活性,经一级质谱分析,获得了13种抗菌活性组分的分子量;经二级质谱分析,将13种抗菌活性物质鉴定为Fengycin A或Fengycin B的同系物或同分异构体。【结论】从N6-34菌株发酵液中分离获得了13种抗菌成分,为杨树溃疡病的生物防治提供了理论依据。

Isolation, purification and structural identification of antimicrobial substances from poplar canker biocontrol strain N6-34

[Background] Poplar canker disease is a kind of poplar branch disease caused mainly by Botryosphaeria dothidea. A strain of endophytic antagonistic bacteria N6-34 was isolated from poplar in the early stage. The results showed that the strain had good antagonistic effect and had strong antagonistic effect on many plant pathogens. [Objective] To isolate and purify the antimicrobial active substances produced by antagonistic bacteria N6-34, and to identify the structure of the active substances. [Methods] Ammonium sulfate salting out, methanol extraction, molecular sieve and high performance liquid chromatography were used to isolate and purify the antimicrobial active substances produced by strain N6-34. The structure of the active substances was identified. [Results] The fermentation broth of strain N6-34 was purified by multi-step separation and 14 components were obtained, of which 13 components had antimicrobial activity. The molecular weights of 13 antimicrobial components were obtained by MS and the structure of these 13 components was identified as homologues or isomers of Fengycin A or Fengycin B. [Conclusion] Thirteen antimicrobial components were isolated from fermentation broth of strain N6-34, which provided theoretical basis for biological control of poplar canker.