Guangxi Zhiwu (Jul 2023)
Diversity and antibacterial activity of endophytic fungi from Miao medicine Berchemia polyphylla var. leioclada
Abstract
To explore the fungal taxa, distribution and antibacterial activity of Berchemia polyphylla var. leioclada, endophytic fungi of B. polyphylla var. leioclada from Guiyang and Qianxi of Guizhou Province were isolated by tissue fragment separation. Based on the methods of molecular biology and statistics, the endophytic fungi were identificated and their diversity were analyzed. The strains with antibacterial activity were screened by microdilution of broth. The results were as follows: (1) A total of 191 fungal strains were isolated, which were classified into 3 phyla, 5 classes, 10 orders, 15 families and 19 genera. Among all strains, Phyllosticta, Diaporthe, Botryosphaeria and Colletotrichum were the dominant genera. (2) The endophytes fungal Shannon-Weiner diversity index of Berchemia polyphylla var. leioclada in Qianxi (H′Q=2.112) was higher than that in Guiyang (H′G=1.801), and the Sorenson’s similarity coefficient (CsG-Q) was 0.923. The Shannon-Weiner diversity index of different tissues was stem (H′S =2.004)> root(H′R=1.764)> leaf(H′L=1.654)>fruit(H′F=1.473). The similarity index between stem and leaf was the highest, which was CsS-L =0.667. (3) 21 endophytic fungi’ secondary metabolites had inhibitory effects on Escherichia coli, Staphylococcus aureus and Salmonella enterica. The isolate Diaporthe sp. QX4G6 fermentation broth extract have relatively high inhibitory effects, in which the minimum inhibitory concentrations against Escherichia coli, Staphylococcus aureus and Salmonella enterica were 12.5, 6.25 and 12.5 mg·mL-1, and the minimum bactericidal concentrations were 12.5, 6.25 and 12.5 mg·mL-1, respectively. The study reveal rich endophytic fungus resources of Berchemia polyphylla var. leioclada and most of fungi have good antibacterial activity, which lay the foundation for the researchs and development of natural antibacterial drugs or drug sources for endophytic fungi from B. polyphylla var. leioclada.
Keywords
