Antimicrobial evaluation of endophytic fungi inhabiting medicinal plants of the western Ghats of India

Altogether fifteen species of endophytic fungi were recovered from surface sterilized leaf, stem and bark samples collected from eight medicinal plant species sampled in three different locations of the Western Ghats of India. Ethyl acetate extracts of fermentation cultures of these fungi were tested for the production of antimicrobial compounds using a panel of four bacterial strains and Candida albicans. From fifteen species, eight species of endophytes revealed the production of antimicrobial compounds. Partially purified extracts from solid state fermentation of Alternaria sp., Nigrospora oryzae and Papulospora sp. showed inhibitory activity against both Gram-positive and Gram-negative bacteria. In addition, extracts of Alternaria sp., inhibited the growth of Candida albicans. Extracts of Alternaria sp., Nigrospora oryzae and Papulospora sp. are promising enough to deserve further purification and characterization.