Coral reef ecosystems in tropical zones maintain very high and unique biological diversity; this diversity is essential for maintaining marine homeostasis. The coral reef is composed of countless species, including fish, marine algae, and invertebrates (cnidarians, marine worms, mollusks, arthropods, and echinoderms, among others). Additionally, coral reefs harbor an even greater diversity of microorganisms. Various studies indicate that the coral microbiome provides resistance and resilience to corals to face pathogens and warmer oceanic conditions. The unique temperature and pressure conditions of oceanic waters also stimulate the biosynthetic machinery of these microbes to produce novel metabolites with a plethora of biological activities, ranging from antimicrobial, anticancer, and antiparasitic, among others.
Our study examines the chemical ecology and biological activities of the microorganisms associated with the brain coral Pseudodiploria sp. from the Caribbean coast of Panama, aiming to prioritize the bioprospection of metabolites expressed by its microbiome. Using isolation techniques, genetic sequencing, and untargeted GC-MS metabolomics, we have identified and characterized microorganisms associated with this brain coral. Additionally, biological activity screening of cultivable bacteria and fungi isolated has been tested against marine and clinical pathogens.
Preliminary results show a rich diversity of associated bacteria and a low prevalence of fungi in the brain coral. We have identified specific bacterial strains that exhibit significant biological activities against the multidrug-resistant strain Staphylococcus aureus and the marine pathogen Vibrio coralliilyticus through antagonistic interactions and direct inhibition tests. Preliminary metabolomic profiles, based on GC-MS and processed using the GNPS molecular networking bioinformatics platform, reveal various chemical compounds produced by the coral microbiome. These compounds are potentially linked to the observed clinically and ecologically relevant biological activities. Our results offer potential avenues for coral conservation and novel drug discovery strategies.
