黔西南薏苡内生真菌多样性及其抗菌活性研究

为进一步了解贵州黔西南薏苡(Coix lacryma-Jobi)可培养内生真菌的多样性组成及其抗菌活性。通过组织块分离法,选取薏苡根、叶和种仁为分离对象,进行内生真菌分离,并通过形态学观察,分子生物学特征对所分离内生真菌进行鉴定。采用平板菌块对峙法对薏苡内生真菌进行抗菌活性筛选。从薏苡根、叶和种仁中共分离纯化获得76株薏苡内生真菌,根据形态和分子生物学特征,它们属于10个目、14个科、26个属和1个不明属以及未知菌;以大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphyloccocus aureus)、枯草芽胞杆菌(Bacillus subtilis)、酿酒酵母(Saccharomyces cerevisiae)为指示菌株,对薏苡内生真菌进行抗菌活性筛选。其中有25株对大肠杆菌具有抗菌活性,占分离菌株的比例为32. 9%;有34株对金黄色葡萄球菌具有抗菌活性,其比例为44. 7%;有24株对枯草芽胞杆菌具有抗菌活性,比例是31. 6%;有23株对酿酒酵母具有抗菌活性,占比例为30. 3%;对4种标准菌株都有抗菌活性的有13株,占总株数的17. 1%。薏苡的不同组织结构中存在丰富的内生真菌资源,部分内生真菌具有抑制其他微生物生长的活性,具有产生天然活性产物成分的潜力,为工业应用奠定了资源基础,具有进一步发掘和研究的价值。

Study on the diversity and antimicrobial activity of endophytic fungi from Coix lacryma-jobi in southwest Guizhou

To further understand the diversity and antimicrobial activity of the endophytic fungi from Coix lacryma-jobi, the roots, leaves and seeds of coix were selected as the objects of isolation by tissue block method. The endophytic fungi were isolated and identified by morphological observation and molecular biological characteristics (5.8S and ITS). 76 strains of coix endophytes were isolated and purified from the roots, leaves and seeds. According to their morphological and molecular biological characteristics, they belonged to 10 orders, 14 families, 26 genera, 1 unknown genus and unknown strains. Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Saccharomyces cerevisiae were used as indicater strains to screen the antimicrobial activity. 25 strains showed antimicrobial activity against E.coli, accounting for 32.9% of the isolated strains. 34 strains showed the activity against S.aureus, accounting for 44.7% of the isolated strains. 24 strains showed the activity against B. subtilis, accounting for 31.6% of the isolateds. 23 strains showed the activity against S.cerevisiae, accounting for 30.3% of the isolates. 13 strains showed the activity against all of 4 indicater strains, accounting for 17.1% of the isolates. There are abundant resources of endophytic fungi in different tissues of coix, and some endophytic fungi produce natural active products, which lays a resource fundation for industrial application and has the value of further exploration and research.