红树林内生真菌的分离及代谢产物生物活性的初步研究

Isolation and Metabolite Bioactivities of Mangrove Fungal Endophytes

从8种红树林植物中共分离出85株内生真菌,经鉴定发现其主要类群为无孢类群(Mycelia sterilia),短梗霉属Aureobasidium spp.和盘长孢属Gloeosporium spp.,分别占菌株总数的50.6%、18.0%、14.6%。对这85株内生真菌的代谢产物生物活性研究发现:其菌丝和发酵液提取物对试验细菌表现出较好的抗性:对大肠杆菌有抗性的菌株比例分别为22.4%、21.2%、金黄色葡萄球菌为12.9%、14.1%,枯草芽胞杆菌为20.0%、36.5%;其发酵液提取物对酿酒酵母Saccharomyces cerevisiae、白色念珠菌Candida albicans、新月弯孢霉Curvular-ia lunata等试验真菌均有较好的抗性,抗性菌株占菌株总数的比例分别为25.9%,23.5%,28.2%,而菌丝提取物均未表现出抗性;有8株(占菌株总数的9.0%)可产生抑制小麦发芽和芽生长的代谢物,具有除草剂活性;通过本实验建立的全细胞定向筛选模型发现:有14个菌株的代谢产物对耐药性大肠杆菌具有拮抗活性,占菌株总数的16.5%。以上结果表明:红树林内生真菌蕴含丰富的生物活性物质,在新型药物先导物和除草剂的开发方面都表现出潜在的应用前景。

Eighty-five endophytic fungi strains were isolated from eight kinds of mangrove plants. The main taxa are mycelia sterilia, Aureobasidium spp. and Gloeosporium spp., accounting for 18.0%, 14.6% of the total strains respectively. Their metabolite bioactivities were primarily studied. Results in- dicated that the extract of hypha and fermentation liquor have good inhibition activity to test bacteria, the active strains proportion to Escherichia coli is 22.4% , 21.2% respectively, to Staphylococcus aureus is 12.9% , 14. 1% , to Bacillus subtilus is 20.0% , 36.5% ; fermentation liquor also has good inhibition activity to Candida albicaus, Saccharomyces cerevisiae, Curvularia lunata, accounting for 25.9%, 23.5%, 28.2% of the total strains respectively, but their hypha extract has no inhibition activity to test fungi. Metabolites of eight strains （ occupying 9.0% of the total strains） can inhibit germination and bud growth of wheat and have herbicidal activity. Metabolites of fourteen strains （occupying 16.5% of the total strains） can inhibit antibiotic-resistance E. coli by whole-cell targeted screening model. These results showed mangrove fungal endophytes would be a rich resource pool for new drug and herbicide.