Identification of endophytic actinomycete Lj20 from plant and its antifungal substances
Lin Ma,Hongbing Chen,Jucai Han,Huiping Liu (College of Agriculture,Shanxi Agricultural University,Taigu 030801,China)
[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 biochemi-cal 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.