Detection of antifungal endolichenic fungi and antifungal compound

Abstract

To isolate a novel antifungal compound, we obtained 571 kinds of endolichenic fungi from Lichen Bioresources Center and examined their antifungal abilities. Four fungi Stereocaulon sp. (1429), Stereocaulon sp. (1430), Cryptosporiopsis sp. (0156), and Graphis sp. (1245) showed high antifungal activity against Candida albicans when they grew in both liquid and solid media. We extracted the culture supernatants of these fungi with chloroform and then ethyl acetate. The chloroform fraction exhibited the highest anti-fungal activities when those fractions were examined for the growth inhibition of Candida albicans with disc diffusion method. To see information for the inhibitor present in chloroform fraction we employed GC-MS for the fractions of Stereocaulon sp. (1429). We found that hexamethylcyclotrisiloxane, decanoic acid, hexadecanonic acid-methyl ester, 14-octadecenoic acid-methyl ester, and octadecenoic acid-methyl ester were present more in chloroform fraction than in ethylacetate fraction. This indicates that those compounds could be possible antifungal candidates since antifungal activity of chloroform extract was two times higher than that of ethyl acetate extract. © 2013, The Microbiological Society of Korea.