采用选择性分离方法对药用植物红豆杉Taxus chinensis嫩枝和叶进行内生菌分离,得到一株放线菌En-1,经鉴定为链霉菌Streptomyces sp.;并对该菌进行液体培养条件优化、次生代谢物初筛及其抗菌活性的研究.通过添加宿主植物浸出物至En-1液体培养中以考察宿主对后者生长的影响,结果表明红豆杉叶浸出物能促进En-1的体外生长；而且En-1次生代谢物对5株供试菌中的黑曲霉具有抑制活性.通过En-1菌培养基优化并联合波谱法检测其发酵产物,显示8#配方(淀粉25 g·L-1,KNO3 1 g·L-1,K2HPO4·3H2O 0.5 g·L-1,NaC10.5 g·L-1,FeSO4·7H2O 0.01 g·L-1,MgSO4·7H2O 0.5 g·L-1)培养液中,En-1所产的次生代谢物最具结构多样性；同时8#配方也有利于该菌产生抗菌活性产物.本研究提示红豆杉内生放线菌可作为寻求药物先导化合物的资源菌.%This paper describes the selective isolation of endophytic actinomycete En-1 from the twigs and leaves of Taxus chinensis, and focuses on the optimization of liquid suspension culture conditions of En-1 strain, the spectroscopic screening of its secondary metabolites as well as the anti-microbial activity of its fermentative filtrates. Of the endophytic isolates, an actinomycete En-1 strain was obtained, which was characterized as Streptomyces sp. Based on 16SrDNA sequencing and morphological features. The supplementation of Taxus leaf extract into the suspension culture of En-1 demonstrated that the leaf extract from host plant could promote the in-vitro growth of En-1. Moreover, the anti-microbial activity assay showed that the secondary metabolites of En-1 had inhibitory effects on Aspergillus niger, among the type microbial strains tested. Furthermore, the optimization of En-1 culture media coupled with the screening of the structural diversity of its secondary metabolites was carried out. Results have demonstrated that the formulation No. 8 (Starch 25 g·L-1, KNO31 g·L-1, K2HPO4·3H2O 0.5 g·L-1, NaCl 0.5 g·L-1, FeSO4·7H2O 0.01 g·L-1, MgSO4·7H2O 0.5 gL-1), was most suitable for En-1 to produce chemically structurally-diverse secondary metabolites with anti-fungal activities, among the nine medium formulations examined. It is suggested that the endophytic actinomycetes from medicinal plants could serve as the sources of pharmaceutical lead compounds.
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