DOI: 10.2478/cjf-2025-0011
Original scientific paper
PROBIOTIC POTENTIAL OF CORAL MICROBIOTA: A NATURAL DEFENCE AGAINST WHITE SYNDROME
2025, 83 (3) p. 99-107
Ratna Palupi, Anindita Sabdaningsih, Diah Ayuningrum, Agus Sabdono
Abstract
Bacteria found in healthy corals produce bioactive compounds with antimicrobial properties that can help fight pathogens responsible for coral diseases. This potential can be harnessed for biocontrol, particularly against the deadly White Syndrome (WS). This study aims to identify beneficial bacteria from healthy corals that could serve as WS control agents. Coral samples, both healthy and WS-infected, were collected from Sawopudo waters in Southeast Sulawesi, Indonesia. Bacteria were isolated using spread and streak plate methods, and their antibacterial activity was tested in vitro using the agar plug assay. Isolates displaying strong inhibition zones underwent 16S rRNA gene sequencing to determine species similarity. The most promising candidates were further tested in vivo by inoculating WS-infected corals with isolates from healthy corals. Among the six bacterial isolates with antimicrobial potential, those with the largest inhibition zones showed high similarity to Bacillus tequilensis (99.79% and 99.93%), Micrococcus luteus (99.43%), Cytobacillus firmus (99.93%), Staphylococcus arlettae (99.79%), and Priestia aryabhattai (99.86%). The in vivo tests identified Cytobacillus firmus as the most effective WS control agent, forming a 16.6 mm inhibition zone and restoring up to 20% of infected coral tissue. These findings highlight a promising approach for combating White Syndrome, a major threat to coral reef ecosystems.
Keywords
bacterial coral symbiont, coral disease, Cytobacillus firmus