Study On Endophytic Fungi And Its Active Metabolites From Glycyrrhiza

Glycyrrhiza uralensis, a frequently used herb, is on the edge of extinction. This work aims to isolate endophytes and their metabolites in order to provide the valuable scientific foundation for the rational utilization of Glycyrrhiza uralensis and to preserve resources.In this paper, healthy plants of Glycyrrhiza uralensis were collected from Daqing in Heilongjiang Province, and 46 endophytic fungi were separated by tissue isolating method. All of them were classified and identified according to their morphological and micro-structure characteristics. The results showed that these fungi belong to thirteen genera, five families, and four orders part from three unknown species. Fusarium sp. and Penicillium sp. were the dominant endophytic fungi population in Glycyrrhiza uralensis, which accounted for 41.3% in 46 strains.46 strains of endophytic fungi and their secondary metabolites were screened through antimicrobial activities against 12 kinds of pathogens, such as Escherichia coli, Staphlococcus aureus, Candida albicans and so on. The results indicated that diverse antimicrobial natural products existed in endophytic fungi of Glycyrrhiza uralensis and their fermentation broths.Meanwhile, the fermentation broths of 19 strains of endophytic fungi were analyzed by HPLC, and the result indicated that the fungus of RP4 strain possibily contained Liquiritin and the fungi of RE5 and RE9 strains possibily contained Glycyrrhetinic acid.Furthermore, RE5 strain was identified by morphological characteristics and 18S-rDNA sequence analysis. The results indicated that RE5 strain belongs to Fusarium oxysporum.