水葫芦内生菌分离及真菌代谢产物初探

从水葫芦的根茎叶器官中分离纯化出7株内生菌（6株细菌,1株真菌）,经分子生物学鉴定,内生真菌为毛霉科匍枝根霉属中的匍枝根霉;并对7株内生菌粗提物以4株细菌（金黄色葡萄球菌、大肠埃希氏杆菌、苏云金芽孢杆菌和枯草芽孢杆菌）和5株农业病原菌（苹果腐烂菌、葡萄白腐真菌、白菜黑斑病菌、棉花枯萎病菌、高粱炭疽病菌）为指示菌株,采用滤纸片法进行抑菌活性测定.结果发现只有内生真菌对4株细菌有一定的抑菌活性,对5株农业病原菌中的葡萄白腐真菌有微弱的抑制活性,而细菌没有表现出明显的抑菌活性.通过对分离获得的内生真菌进行发酵、分离和纯化的研究,并根据质谱和核磁共振等谱学数据鉴定了一个过氧化麦角甾醇的化学结构.

Preliminary study on separation and purification of endophytic microorganism from water hyacinth and metabolic product from Eichhornia crassipes fungus

Seven strains endophytic microorganism, including 6 strains bacteria and 1 fungus have been separated and purificated from water hyacinth tissue. The endophytic fungus is indentificated as Eichhornia crassipes by molecular biology techniques. Four strains bacteria （S. A. ,E. C. ,B. T. and B. S. ）and five strains pathogenic fungi （PGFL,PTBF,BCHB,MHKW and GLTJ）are used as indicators to test microbial inhibition activity by using the disk diffusion method. It is found that only the secondary metabolites crude extracts of the endo phytic fungus reveal moderate activity against four bacteria strains, and weak activity against pathogenic fungus of PTBF. Six endophytic bacteria seldom have any antibacterial activities. One steroid is isolated from the endophytic fungus. The compound is isolated from the fermentation extracts by repeated column chromatography （CC） on silica gel,Sephadex LH-20, preparative thin layer chromatography （pTLC）. The chemical structure is elucidated by means of spectroscopic methods including MS and NMR, named as （22E, 24R）-5α, 8α- epidioxyergosta-6, 22-dien-3β-ol.