Antimicrobial pontential of fungal endophytes obtained from Avicennia Marina and Excoecaria Agallocha in Negombo

Mangroves are halophytic plants that are typically found along the intra-tidal regions. The coastal ecosystem of mangroves in Sri Lanka hold one of the most unique mangrove species that are yet to be studied. These ecosystems provide shelter to various organisms including humans. Fungal endophytes present in these plants have many medicinal properties that can be utilized in the development of drugs. Antibiotic resistance is a major concern in the pharmaceutical industry, hence alternative plant-based drugs with fewer costs and side effects show great potential. In the current investigation, the main objective was to test for antibacterial properties of fungal endophytes isolates from two mangroves: Avicennia marina and Excoecaria agallocha against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). In both mangrove species, three endophytic species were identified based on their morphological characteristics: Aspergillus niger, Penicillium viticola and Aspergillus versicolor. Only P. viticola was obtained from E. agallocha. Based on the results obtained from antibiotic susceptibility tests, A. niger (stem) was the most active and showed the best bacteriostatic and bactericidal activity against both S. aureus and E. coli. P. viticola produced viable results (mean zone of inhibition of 21 mm against S. aureus) but were not as productive as A. niger. This study indicated that these endophytic fungi held medicinal properties that can be further evaluated.