Screening of Antimicrobial Activities of the Endoph ytic Fungi Isolated from Sesbania grandiflora (L.) Pers.

Abstract

The purpose of this research was to study the antim icrobial activities of the endophytic fungi from Sesbania grandiflora (L.) Pers. The endophytic fungi were isolated from branches and leaves of Sesbania grandiflora (L.) Pers., and sixty nine isolates were obtained. All isolates were screened for antibacter ial and antifungal activities. The indicator organisms were 4 bacteria including Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853, two yeasts, namely, Candida albicans and Cryptococcus neoformans, and 6 molds including Rhizopus spp . , Mucor spp., Penicillium spp., Aspergillus spp . , Curvularia spp . , and Alternaria spp . . It was found that 28 and 16 isolates showed antib acterial activity against gram positive and gram negative ba cteria, respectively. Also, 11 and 17 isolates showed antifungal activity against yeasts and hyaline non-septate hyphae, respectively. Besides, 13 and 65 isolates showed an tifungal activity against hyaline septate and dematiaceous, respectively. There were 9 isolat es that could inhibit bacteria, yeast, and molds. Macroscopic and microscopic examination of the fungal morphology revealed that most of the endophytic fungi (25 isolates) wer e hyaline septate hyphae. Only 3 isolates were hyaline non-septate hyphae. Fusarium spp . and Acremonium spp . were the predominate species among the isolated endophytic f ungi. These results indicated that some endophytic fungi isolated from Sesbania grandiflora (L.) Pers. were potential sources of antimicrobial compounds against the tested bacte ria, yeasts, and molds. Keywords : Antifungal activity, Bioactive compounds, Co-evol ution relations, Host plants.