Antioxidant and antimicrobial properties of marine actinomycetes from sipadan Island, Sabah

Marine actinomycetes have great potential as producers of unique bioactive compounds due to its special adaptation in the harsh environment in the ocean. In this study, 100 strains of actinomycetes were isolated from marine sponges collected from sea area close to Sipadan Island in Sabah. Each strain was fermented in mannitol-peptone broth and the secondary metabolites were extracted by using acetone. The secondary metabolites were tested for their antimicrobial and antioxidant activity. The data showed that 22 strains exhibited potent antioxidant activity (IC50 between 56.3 and 99.1 µg/ml) in DPPH assay and 31 strains have strong inhibition activity (8 mm to 19 mm) on test pathogens (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Klebsiella spp., Streptococcus pneumonia and Pseudomonas aeruginosa) in antimicrobial assay. These results give evidence that it is essential to scrutinize these under explored marine microbes in search of new drugs which have great potential to be used in the pharmaceutical fields