ILMU KELAUTAN December 2017 Vol 22(4):185-192 ISSN 0853-7291 *) Corresponding author © Ilmu Kelautan, UNDIP ijms.undip.ac.id DOI: 10.14710/ik.ijms.22.4.185-192 Received : 11-09-2017 Accepted : 14-10-2017 Bioecology of Sargassum sp. and its Extract Bioactivity as Anti-MDR Bacteria Rini Pramesti 1* , Wilis Ari Setyati 1 , Muhammad Zainuddin 2 , and Maya Puspita 3 1 Department Marine Science, Diponegoro University Jl. Prof. H. Soedarto, S.H, Tembalang, Semarang, Central Java 50275 Indonesia 2 Aquaculture Department, Nahdlatul Ulama Islamic University Jl. Taman Siswa, Pekeng, Tahunan, Jepara, Central Java 59427 Indonesia 3 University of South Brittany EA 3884. LBCM. IUEM. F-56000 Vannes, France Email: rinipramesti63@gmail.com Abstract This study was done to investigate the bioecology and extract bioactivity of Sargassum sp from Jepara district. Seaweed was collected from Teluk Awur, Panjang Island, Bandengan, Ujung Piring and Bondo. There were seven species of Sargassum identified i.e. S. duplicatum, S. polycystum, S. echinocarpum, S. cinerium, S. crassifolium, S. plagyophillum and S. binderi. Community structure indices were calculated based on data collected by survey. Antibacterial activity of Sargassum extract was done on MDR bacteria. The results showed that diversity index at Panjang Island, Bandengan, and Ujung Piring were categorized as medium, while Teluk Awur and Bondo were categorized as low. Evenness index was high at Teluk Awur, Panjang Island, Bandengan and Ujung Piring and Bondo was low. There was no dominant species found in most of the locations. The principal component analysis exhibited the main variable that affected the Sargassum at Teluk Awur was phosphate, Panjang Island was depth, Ujung Piring was salinity and Bondo was temperature, dissolved oxygen and pH, respectively. There was character similarity between Panjang Island and Bandengan (99.73%), meanwhile, at Teluk Awur, Ujung Piring, and Bondo, the similarity was 99.62%, 99.60%, and 99.52%, respectively. Antibacterial activity of Sargassum sp. demonstrated a positive activity against the MDR bacteria, Staphylococcus aureus (6.28±0.04 mm), Escherichia coli (6.96±0.19 mm), and S. epidermidis (12.65±0.23 mm). Clustering analysis of extracts with bactericidal characteristic found three classes with similarity of class 1, 2 and 3 at 72.33%, 76.80% and 58.50%, respectively. Sargassum sp. was categorized in class 1 had the best antibacterial activity and the highest abundance value. Keywords: ecology, community, Sargassum sp., extracts, antibacterial Introduction Research on seaweed, Sargassum sp., has been conducted quite extensively but information that explains about environment towards distribution, diversity, and bioactive abundance from Sargassum sp. is limited. Sargassum sp. has been reported to show promising pharmacological properties serving as antiviral (Hardouin et al., 2013), antitumor (Nianjun et al., 2004), antioxidant (Rastian et al., 2007; Bhaigyabati, 2011; Zaragoza et al., 2008; Khaled et al., 2012; Tanniou et al., 2013), antifouling (Plouguerne et al., 2010), and antifungal (Manivannan, 2011; Khaled et al., 2012). S. fulvellum and S. thunbergii showed antiphyretic, analgesic, and anti-inflammatory activities in mice (Kang et al., 2008). S. echinocarpum, S. duplicatum and S. polycystum performed potential antioxidant (Widowati et al., 2014). S. aquifolium, S. ilicifolium and S. polycystum showed antibacterial activity against Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli (Puspita et al., 2012). S. pallidum can serve as antioxidant and anti- hemolysis agents exhibiting potential for further exploration as functional food or complementary medicine (Bhaigyabati et al., 2011; Li et al., 2017). S. tenerrimum from India is reported to have antibacterial activity against Klebsiella pneumonia, Escherichia coli, Staphylococcus aureus, Proteus sp., Streptococcus sp., Pseudomonas aeruginosa, Salmonella sp., Shewanella sp., Vibrio fluvialis, V. splendidus, V. cholera, V. parahaemolyticus, Shigella flaxneri, Staphylococcus epidermidis, Aeromonas liquefaciens and Bacillus subtilus. Furthermore, Sargassum sp. also have antifungal activity against Aspergillus niger, A. flavus, A stetreus, Candida albicans and Penicillum sp. (Manivannan et al., 2011). The above research focuses only on the perspective of active compounds, but which relates to ecological factors is very limited. This study was