植物内生放线菌Lj20的鉴定及其抗真菌物质的合成

Identification of endophytic actinomycete Lj20 from plant and its antifungal substances

摘要:

【目的】菌株Lj20是从辣椒植株根部分离得到的一株有抗真菌活性的植物内生放线菌。为了进一步开发利用这一放线菌，对其进行了鉴定及抗菌活性物质的研究。【方法】根据Lj20的形态特征、培养特征、生理生化特征、细胞壁组分和16S rDNA序列对其进行鉴定。结合GC-MS分析，合成了代谢产物中所含的抗真菌活性物质，并用菌丝生长抑制法测定其生物活性。【结果】Lj20菌株属于链霉菌属，与娄彻氏链霉菌（Streptomyces rochei）极为相似。代谢产物中含有2, 6-二叔丁基对甲酚和3, 5-二叔丁基-4-羟基-苯甲醚。两种化合物对番茄灰霉病菌的EC50值分别为237.04 mg/L和186.48 mg/L。【结论】菌株Lj20鉴定为娄彻氏链霉菌（Streptomyces rochei）。2, 6-二叔丁基对甲酚和3, 5-二叔丁基-4-羟基-苯甲醚对番茄灰霉病菌都有较强的抑制作用。

Abstract:

[Objective] Endophytic actinomycete Lj20 with antifungal activity was isolated from the roots of capsicum plants. We identified Lj20 and synthesized its antifungal substances. [Methods] Morphological, biological and biochemical characteristics, chemotaxonomy analysis and 16S rDNA sequences were used to identify Lj20. According to GC-MS extrapolation result, one of antifungal substances in the metabolites of Lj20 was chemically synthesized. The bioactivities were determined by mycelium growth inhibition method. [Results] Lj20 belonged to Streptomyces sp. and was similar to Streptomyces rochei. The metabolites contained butylated hydroxytoluene and 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether. The median effective concentration (EC50) of these two compounds to Botrytis cinerea Pers. were 237.04 mg/L of the water and 186.48 mg/L of the water, respectively. [Conclusion] Lj20 was classified as Streptomyces rochei. Butylated hydroxytoluene and 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether had significant inhibition to the pathogen.