RÉSUMÉ
Sponge diversity along the coasts of Andaman and Nicobar Islands comprises about 126 species and sponges are knownto act as a host to endosymbionts, which is found to possess novel antimicrobial metabolites. In the present study,screening and characterization of antibiotic producing endosymbiotic bacteria from the marine sponge Lamellodysideaherbacea were investigated. Eight isolated bacterial strains from the sponge were screened for bioactivity againsthuman pathogens Escherichia coli (MTCC 443), Bacillus cereus (MTCC 430), Bacillus subtilis (MTCC 121), Listeriamonocytogenes (MTCC 839), Staphylococcus aureus (MTCC 3160) and Salmonella enterica typhimurium (MTCC1252) and only two strains CAB1 and CAB38 exhibited activity. Ethyl acetate extracted metabolites of strain CAB1showed significant activity against four pathogens B. cereus, B. subtilis, S. aureus and S. entrica typhimurium andCAB38 against three pathogens B. subtilis, E. coli and S. entrica typhimurium. The 16S rRNA gene sequence of thesetwo strains showed 99% sequence similarity with known sequences in the GenBank and their phylogenetic analysisconfirmed strain CAB1 as Bacillus amyloliquefaciens (MK135790) and CAB38 as Alcaligenes faecalis (MK135791).The study demonstrated that metabolites from sponge associated bacterial endosymbionts can be a major source ofunique compounds with potential bioactivity.
RÉSUMÉ
Sponge diversity along the coasts of Andaman and Nicobar Islands comprises about 126 species and sponges are knownto act as a host to endosymbionts, which is found to possess novel antimicrobial metabolites. In the present study,screening and characterization of antibiotic producing endosymbiotic bacteria from the marine sponge Lamellodysideaherbacea were investigated. Eight isolated bacterial strains from the sponge were screened for bioactivity againsthuman pathogens Escherichia coli (MTCC 443), Bacillus cereus (MTCC 430), Bacillus subtilis (MTCC 121), Listeriamonocytogenes (MTCC 839), Staphylococcus aureus (MTCC 3160) and Salmonella enterica typhimurium (MTCC1252) and only two strains CAB1 and CAB38 exhibited activity. Ethyl acetate extracted metabolites of strain CAB1showed significant activity against four pathogens B. cereus, B. subtilis, S. aureus and S. entrica typhimurium andCAB38 against three pathogens B. subtilis, E. coli and S. entrica typhimurium. The 16S rRNA gene sequence of thesetwo strains showed 99% sequence similarity with known sequences in the GenBank and their phylogenetic analysisconfirmed strain CAB1 as Bacillus amyloliquefaciens (MK135790) and CAB38 as Alcaligenes faecalis (MK135791).The study demonstrated that metabolites from sponge associated bacterial endosymbionts can be a major source ofunique compounds with potential bioactivity