其他摘要：ABSTRACT The aims of this study were to obtain sponge-associated bacteria as biocontrol to inhibit vibriosis in vitro and in vivo, to identify the bacterial isolates based on 16S-rRNA gene, and to detect the presence of nonribosomal peptide synthetase (NRPS), and polyketide synthase (PKS) genes to prove its ability of bioactive compounds synthesis. Aaptos sp. and Hyrtios sp. sponges were collected from Pramuka Island, Jakarta. The isolation using sea water complete (SWC) and zobel marine agar (ZMA) medium obtained 174 isolates. A total 69 isolates were screened successfully based on their antibacterial activity. 47 isolates showed negative haemolysis through hemolytic assays. The pathogenicity test used twelve selected isolates that have a broad spectrum of antibacterial activity and haemolysis negative. The result of pathogenicity test showed that 12 isolates were not pathogenic to the shrimp post larvae with no significantly different (P>0.05) between treatment and negative control. Results of challenge test with Vibrio harveyi have a significant difference survival (70±5.0–90±0.0%) (P<0.05) compared with positive control (38.3±2.9%). Genetic analysis based on 16S-rRNA revealed the groups of three genera belonged to Pseudomonas , Staphylococcus, and Alcaligenes . Based on amplification of NRPS and PKS genes, four bacterial isolates have been detected to have only NRPS gene, one isolate has only PKS, and one isolate has both genes. The results indicate that the potency of six sponge-associated bacteria as bioactive compounds producers.
