Isolation and Screening Antimicrobial Activity of Actinomycetes from Sediment's Coastal Pramuka Island, Kepulauan Seribu, Jakarta, Indonesia

Twenty-two isolates of actinomycetes have been isolated from sediment in coastal Pramuka Island, Kepulauan Seribu, Jakarta, Indonesia. Plate method was used for isolating actinomycetes on Zhang' Starch Soil Extract (ZSSE). All of the isolates were grown in Cross Streak Medium (CSM) agar plate. Strains were screened for antimicrobial activity by using plug method and their activities were determined by antimicrobial Activity Index (AI). The result showed that 13 isolates inhibited Staphylococcus aureus NBRC 100910 (0.461-2.338), 19 isolates inhibited Kocuria rhizophila NBRC 12708 (0.705-8.200), five isolates inhibited Candida albicans UICC Y29 (0.885-0.357), and four isolates inhibited Saccharomyces cerivisiae UICC Y17 (0.357-1.348). No inhibition activity was observed in the Escherichia coli NBRC 3301. Based on the results of antimicrobial test, SD17 is the most potential strain since it is able to inhibit all Gram positive and yeast tested.