Abstract
Symbiotic bacteria play vital roles in the survival and health of marine sponges. Sponges harbor rich, diverse and species-specific microbial communities. Symbiotic marine bacteria have increasingly been reported as promising source of bioactive compounds. A culturomics-based study was undertaken to study the diversity of bacteria from marine sponges and their antimicrobial potential. We have collected three sponge samples i.e.
Acanthaster carteri
,
Rhytisma fulvum
(soft coral) and
Haliclona caerulea
from north region (Obhur) of Red Sea, Jeddah Saudi Arabia. Total of 144 bacterial strains were isolated from three marine sponges using culture dependent method. Screening of isolated strains showed only 37 (26%) isolates as antagonists against oomycetes pathogens (
P. ultimum
and
P. capsici
). Among 37 antagonistic bacteria, only 19 bacterial strains exhibited antibacterial activity against human pathogens (Methicillin-resistant
Staphylococcus aureus
(MRSA) ATCC 43300
, Pseudomonas aeruginosa
ATCC 27853,
Escherichia coli
ATCC 8739,
Enterococcus faecalis
ATCC 29212). Four major classes of bacteria i.e
γ-Proteobacteria
,
α-Proteobacteria, Firmicutes
and
Actinobacteria
were recorded from three marine sponges where
γ-Proteobacteria
was dominant class. One potential bacterial strain
Halomonas
sp. EA423 was selected for identification of bioactive metabolites using GC and LC-MS analyses. Bioactive compounds Sulfamerazine, Metronidazole-OH and Ibuprofen are detected from culture extract of strain
Halomonas
sp. EA423. Overall, this study gives insight into composition and diversity of antagonistic bacterial community of marine sponges and coral from Red Sea and presence of active metabolites from potential strain. Our results showed that these diverse and potential bacterial communities further need to be studied to exploit their biotechnological significance.