Endophytic fungi are those that grow intra- or intercellular within the tissues of higher plants without causing a disease. This study aims to evaluated antimicrobial and cytotoxic activities of endophytic fungi from leaf, bark and root of mangrove Sonneratia alba Sm, collected from Bungus, West Sumatra, Indonesia. The isolation of endophytic fungi was done by using direct planting method with sabouraud dextrose agar (SDA) as growth medium. Thirteen isolates fungi strains were obtained from this mangrove. They were cultivated on unpolished rice as medium for ± 4 weeks, and extracted with ethyl acetate. The ethyl acetate extracts were analyzed for antimicrobial and cytotoxic activities by using agar diffusion method and MTT assay on T47D and Vero cells. The study revealed nine (69%) of the total extract had antimicrobial activity against pathogenic bacteria and fungal such as, Staphylococcus aureus, Escherichia coli and Candida albicans. While nine extracts (69%) were cytotoxic (Percentage of cell viability 50) against T47D cells. Based on the results of antibacterial activity screening, three fungal isolates were selected as the most active against S. aureus, E. coli and C. albicans. This selected fungal isolates were first macroscopically and microscopically characterized and later molecularly identified as Trichoderma koningiopsis, Aspergillus sydowii and Trichoderma lixii respectively. This study concluded that the endophytic fungi of Sonneratia alba Sm can be developed as a new source of antibiotic and anticancer compounds.
Key words: Endophytic fungi, mangrove, Sonneratia alba Sm, antimicrobial activity, cytotoxic activity, Trichoderma koningiopsis, Aspergillus sydowii, Trichoderma lixii