植物内生放线菌Lj20的鉴定及其抗真菌物质的合成

目的]菌株Li20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EC<,50>值分别为237.04 mg/L和186.48 mg/L.结论]菌株Li20鉴定为娄彻氏链霉菌(Streptomyces rochei).2,6-二叔丁基对甲和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.

Identification of endophytic actinomycete Lj20 from plant and its antifungal substances

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.