Screening Anti-Bacterial Activity of Endoi.Ichenic Fungi Collected From Negombo Lagoon Sri Lanka

Abstract

From the ancient past, natural products have been in use to fulfill a variety of human needs, from sustenance to pharmaceutical necessities. With the discovery of Endolichenic fungi (ELF) as a novel source prominent bioactiOt1es in recent years. a new trend has been created to explore more about these fascinating organisms, which live inside the lichen thallus asymptomatically. ELF isolated from the lichens collected from mangrove plants In Negombo lagoon's Kadol kale area (Lititude: 701 Longitude: were identitied using molecular techniques and were subjected to anti-bacterual assay. Ethyl acetate crude extracts of 18 identified endolichenic fungal strains were obtained and their anti-bacterial activities were tested against aerobic bactertal species Escherichia coli, Bacillus subtilis and Staphvlococcus aureus. The assay was carried out using agar well diffusion method using HI of the extracts (5 mg/ml) with Azithromycin as the positive control. The inhibition zone diameters (in cm) against E. coli were 1.2 for Phanerothaete chnsosporium. 1.2 for Xvlaria feejecnsis, ().9 for Gelasinospora seminuda, 0.9 for Chaetomium globosum and 1.5 for Curvularia lunata while Azithromycin as the positive control showed a diameter of 2.1. The inhibition zone diameters against B. subtilis were 1.0 for Cochliobolus sp., 1.0 for P. chnsosporium, 1.8 for X. feeyeensls, 1.7 for G. seminuda, 1 2 for C. globosum, 1.5 for Hvpoxvlon lividipigmentum, 2.0 for (Pennicillium sp), 2.2 for C. lunata, 0.9 for Lasiodiplodia theobromae and 2.4 for positive control. The inhibition zone diameters against S. aureus were 1.1 for P. chrvsosporium, 22 for X'. feejeensis, 1.0 for G. seminuda, 1.0 for Chaetomium globosum, 2.0 for (Pennicillium sp). 1.8 for Curvularia lunata and 2.2 for positive control. Out of the 18 fungal strains, 9 showed significant activity against the tested bacterial species while Endomelanconiopsis endophvtica, Neofusicoccum parvum. Ncofusicoccum occulatum. Hvpoxvlon anthochroum. Cvtospora xvlocarpi, Cerrena sp., Schi:ophvllum commune, Daldinia eschscholt:i, Nodulisporium sp. fungal strains did not show any inhibition. Further studies will be conducted to isolate compounds responsible for these inhibitions.