Antimicrobial and cytotoxic activities of endophytic fungus Colletotrichum gloeosporioides isolated from endemic tree Cinnamomum malabatrum
Résumé
In a survey of endophytic fungi associated with endemic plant Cinnamomum malabatrum leaves harbored a bioactive endophytic isolate CMS 3 was identified as Colletotrichum gloeosporioides through morphological and phylogenetic analysis based on ITS-rDNA. The ethyl acetate extract of fermentation broth of Colletotrichum gloeosporioides CMS 3 displayed antimicrobial activity against gram positive and gram negative bacteria as well as the fungal pathogen, Candida albicans. The ethyl acetate crude extract showed in vitro cytotoxicity against the HeLa, MCF-7 and MG63 cancer cell lines with the IC50 values of 94.2μg/ml, 84.3μg/ml and 162μg/ml respectively. Gas chromatography and Mass Spectrophotometry (GC-MS) analysis of crude extract confirmed that CMS 3 was a prolific producer of secondary metabolites, in which nearly 74% of the metabolites not listed in the NIST database. Major compounds were phenol 3, 5- dimethoxy acetate (11.82 %), 4'-isopropylidene-bis-(2-cyclohexyl) phenol, N-Didehydrohexacarboxyl-2, 4, 5-trimethylpiperazine and 1, 2, 4-Triazolium ylide. These metabolites may be responsible for its antimicrobial and cytotoxic activities.