Isolation and Characterization of Superior Symbiotic Bacterial Isolates from the Oenggae Sea with Potential as Antibacterial

Abstract

Sponges are one of the marine biota that have a symbiotic relationship with bacteria which can produce secondary metabolites as antimicrobials. The main aim of this research was to isolate and identify bacteria that had potential as antibacterials against multi-drug resistant test bacteria. The sponsor samples used in this research were Stylissa massa, Salvador Dali, and Angelas sp. The methods used were bacterial isolation, morphological and biochemical characterization, molecular identification, antibacterial tests, and molecular identification. The results of the isolation and characterization of superior symbiont bacteria from the sponges Stylissa massa, Salvador Dali, and Angelas sp obtained 85 isolates which were purified with different morphological characters. The results of biochemical tests on TSIA and SCA media, of the 85 isolates, 39 were positive on TSIA media and were able to ferment glucose. The test results on SCA media from 85 isolates were 15, positive on SCA media and the isolates were able to use citrate as a carbon source. Antibacterial test results with the test bacteria Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa. The test results showed that 15 isolates could inhibit the growth of Escherichia coli bacteria, 17 isolates could inhibit Staphylococcus aureus, 34 isolates could inhibit Bacillus subtilis and 12 isolates could inhibit Pseudomonas aeruginosa. The results of the 16S rRNA molecular identification of 6 species of isolates showed that isolates S3C1, S3N6, and S3N7 had genetic similarities to Bacillus velezensis, S3C2 was similar to Bacillus vallimortis, SMZ16 was similar to Bacillus subtilis and SMZ1 was similar to Lysinibacillus macrolides. Optimization results of bacterial isolates S3N6 and S3N7 in the media glucose and NACL were found to be optimal for both isolates at a concentration of 3%. The novelty of this research was that the researchers obtained 4 isolates that could inhibit the test bacteria which could be developed for testing bioactive compounds.