Variation in antibacterial properties of endophytic fungi isolated from Phaeophytes and Rhodophytes of Johor, Malaysia

Abstract

Aim: To identify endophytic fungi of tropical macroalgae and analyse variation in antibacterial activity. Methodology: Endophytic fungi were aseptically isolated from macroalgae tissue, identified by macroscopic and microscopic observations, screened for the presence of antibacterial activity using cross streak and disc diffusion methods against six human pathogenic bacteria. Results: A total of 27 endophytic fungi were isolated and identified from 7 species of macroalgae collected from the Johor coast, Malaysia. Twenty-three fungal isolates belonged to Ascomycota, while two belonged to Zygomycota and Oomycota, respectively. Aspergillus niger was the most common and abundant endophyte found in macroalgal samples. Preliminary screening determined 13 species (48.15%) having positive antibacterial activity. Quantitative analysis of antibacterial activity showed significant differences (p< 0.01) against six human pathogenic bacteria. Two fungal isolates indicated strong and broad-spectrum antibacterial activity namely, Pythium sp. and Trichoderma viride. Interpretation: The findings demonstrate that certain macroalgae-derived endophytic fungi from Johor possess antibacterial properties and can be potentially new antibiotic sources, which are hitherto under-reported.