白木香内生真菌的分离鉴定及其抑菌活性

从白木香Aquilaria sinensis（Lour．）Gilg木质部的树脂形成部位和健康部位中共分离获得42株内生真菌，经初步鉴定，产孢的33株分属于3目4科7属，其余未产孢的9株暂归为无孢菌群。采用杯碟法和MTT法分别测定了各菌株的发酵上清液对3种病原菌的体外抑菌活性和2种肿瘤细胞的体外细胞毒活性。结果表明，白木香木质部健康部位内生真菌以枝顶孢霉属为优势属，而树脂形成部位的内生真菌种类比健康部位要多，且以青霉属为优势属。其中26株至少能抑制一种指示菌，占总数的61．9％；7株对指示瘤株具有细胞毒活性，占总数的16．7％。抑菌活性菌株主要分布在枝顶孢霉属和青霉属。枝顶孢霉属菌株抑菌活性较强，其抗菌活性成分值得进一步研究。

Isolation, Identification and Antimicrobial Activity of Endophytic Fungi in Aquilaria sinensis (Lour.) Gilg

In the present study, 42 strains of endophytic fungi were isolated from the resin formation section and healthy xylem of Aquilaria sinensis (Lour.) Gilg. Among them, 33 strains with sporulation were morphologically classified into 7 genera, 4 families and 3 orders, and the rest 9 strains were tentatively identified as Mycelia sterilia. The antimicrobial activities of the isolates to 3 bacterial pathogens and 2 tumor cells were tested by cylinder plate method and MTT. The results indicated that the endophytic fungi in the resin formation section had more species than those in the healthy xylem, and Acremonium was the dominant genus in the endophytic fungi from the healthy xylem, while Penicillium was the dominant genus in the endophytic fungi from the resin formation section. 26 strains of the isolates (61.9%) could exhibit antimicrobial activities to at least one of the tested pathogens. 7 strains of the isolates (16.7%) showed cytotoxic activities to the tested tumor cells. Antimicrobial strains mainly distributed in the genera of Penicillium and Acremonium. The strains belonging to Acremonium represented stronger inhibitory activities and their antibacterial components are worthy for further study.