Antimicrobial activity of endolichenic fungi isolated from Cryptothecia sp. against some human test pathogens

Cryptothecia sp. is a crustose lichen having varied medicinal properties. The present study aims to isolate and to determine the antimicrobial activity of endolichenic fungi from the surface sterilized lichen thallus of Cryptothecia sp. The isolation was done on three different media i.e., Potato Dextrose Agar (PDA), Malt Extract Agar (MEA) and Water Agar (WA) media. A total of 19 isolates of endolichenic fungi were recovered. The isolates were identified on the basis of colonial morphology and microscopic investigation. Dominant endolichenic fungus was Monilinia sp. (23.33%) followed by Mycelia sterilia (16.66%). Other fungal isolates were Trichoderma sp., Penicillium sp., Aspergillus sp.and Dreschlera sp. The fungal isolates were tested for antimicrobial activity by agar cup diffusion assay against clinically significant human pathogenic test organisms such as Escherichia coli (MTCC 443), Candida albicans (MTCC 227) and Staphylococcus aureus (MTCC 737) procured from IMTECH, Chandigarh. All the isolates exhibited antimicrobial activity against the test pathogens in varying degree. One isolate Penicillium sp., (CRP 3a) showed highest inhibition against all the pathogens. The present study indicated that Cryptothecia sp. harbours various endolichenic fungi with potent antimicrobial activity. Further detailed investigation of the compounds isolated from endolichenic fungi may lead to therapeutic applications as a new source of novel natural products which are helpful to the mankind.