Detection of antibacterial compounds in fungi isolated from Sonneratia caseolaris

Abstract

Previous studies proved that marine-derived fungi contain antimicrobial properties. Lots of researches considered mangrove as the best studied habitat of marine-related fungi. This study was carried out to detect any antibacterial compound from marine fungi isolated from Sonneratia caseolaris or 'berembang' in Malay. Three marine fungal species have been confirmed based on spores and hyphae structure: Haloguignardia oceanica, Carbosphaerella leptoshaerioides and Chadefaudia polyporolithi. Fungal extracts were prepared from the mycelial filtrate, evaporated and reconstituted in 50% ethanol. The extracts obtained were used in antibacterial assay where different volumes of all fungal extracts, (20µ1, 40µ1 and 60µ1) were tested against five bacterial test strains: E. coli, Salmonella sp., Klebsiella sp., Pseudomonas sp. and Streptococcus agalactiae. The results show possible inhibition zones at higher volume of fungal extracts. However, the zone is not clear enough and the diameter is smaller to be indicated as susceptible. In the bioactive compound identification, the separation of active constituents of the extracts was done using Thin Layer Chromatography (TLC) and many different solvent systems at different ratios were tested. However, none of the solvents fully separated the compound in fungal extracts. Further study is therefore needed to identify possible bioactive compounds.