ISSN: 2278‐778X Research Article www.ijbio.com International Journal of Bioassays (IJB) 98 ANTIMICROBIAL ACTIVITY OF ACTINOMYCETES ASSOCIATED WITH AN UNIDENTIFIED SPONGE FROM LEMUKUTAN ISLAND, INDONESIA ON VARIOUS MEDIUM AND INCUBATION TIME Risa Nofiani*, Mega Sari Juane, Safiana, Puji Ardiningsih, Afghani Jayuska and Titin Anita Zahara Department of Chemistry, Faculty of Mathematics and Natural Sciences, The University of Tanjungpura, Jl. A. Yani, Pontianak, Kalimantan Barat, Indonesia‐78124 *Corresponding Author: Risa Nofiani, Department of Chemistry, Faculty of Mathematics and Natural Sciences, The University of Tanjungpura, Jl. A. Yani, Pontianak, Kalimantan Barat, Indonesia 78124 Received for publication: July 17, 2012; Accepted: September 22, 2012. Abstract: Three isolates of Actinomycetes namely MA02, MA03, and MA04 were isolated from an unidentified sponge, Lemukutan Island, Indonesia. They were identified as Streptomyces based on Bergey’s Manual of Determinative Bacteriology. In the preliminary screening, all of the isolates showed antimicrobial activities towards 13 microorganism tests. However, the activities were not similar when their extract produced from various medium and incubation time were tested. Their cultivation was conducted on M13 agar with incubation time for 3 days, M13 broth with incubation time for 4 days, M2+ broth with incubation time for 7 days and M2+ broth with incubation time for 9 days. The result of antimicrobial assay showed difference in the ability to inhibit the microorganism tests. The best antimicrobial activity of the extracts based on cultivated condition (medium and incubation time) for Streptomyces MA02, Streptomyces MA03, and Streptomyces MA04 were M2+ broth for 3 days, M2+ broth for 9 days and M2+ broth for 9 days respectively. Keywords: Antimicrobial Activity, Actinomycetes, Streptomyces, Sponge INTRODUCTION Actinomycetes is a potential antibiotic producer especially genus of Streptomyces. Streptomyces contributes in high production of bioactive compounds especially antimicrobial compounds which is around 80% of the total antimicrobial compounds 5 . Recently, discovery of novel antimicrobial compounds from terrestrial have been decreased so that is needed to explore another Actinomycetes habitat such as marine. Actinomycetes isolated from marine have higher probability to get novel bioactive compounds due to characteristic difference of the structure. Generally, compound structures from marine have more halogenation with bromine and chlorine than terrestrial structures 3 which are caused by uniqueness of marine environment. Sea water contains bioactive compounds such as vitamin and inhibitor agent 4 which can probably be used to induce microorganisms to produce bioactive compounds. Simbiosis between microorganisms and marine invertebrates is also stimulate microorganisms to produce biactive compounds. For instance, sponge associated Actinomycetes. Abundance of Actinomycetes is dominant in the sponge compared with other microorganisms which is around one‐sixth from all microorganisms 7 . Micromonospora and Streptomyces isolated from the sponge‐associated Actinomycetes from the China Seas shows antimicrobial activity 8 . Among genus of Actinomycetes, marine Streptomyces showes higher potential antimicrobial compared with other actinomycetes (Nocardia sp. and Actinolyspora sp.) especially against Staphylococcus aureus and Pseudomonas aeruginosa 2 . Marine Streptomyces species from sediment Mahabalipuran sea shores and Adyar Estuary can inhibit growth more microoganism test than another Actinomycetes 6 . Therefore, the objective of this study is to get potential genus Actinomycetes having antimicrobial activity from an unidentified sponge Randayan Island, Indonesia. In addition, we learn effect of various medium and incubatian time towards antimicrobial substance production from Actinomycetes associated with an unidentified sponge. MATERIALS AND METHODS Collection of Sponge Sample: An unidentified sponge was collected from Lemukutan Island, Kalimantan Barat, Indonesia. The sponge was placed on polyethylen bag containing seawater then closed tightly and stored in the cool box. The depth of sponge from the surface was measured. Apart from the sponge, seawater was collected to measure salinity, pH, and temperature. Preparation and Isolation of Streptomyces from an unidentified sponge: Approximately 20g sponge which was rinsed sterilized seawater was added 50mL of sterilized seawater then it was homogenized using