Potential chemical defenses of Antarctic benthic organisms against marine bacteria

• Published in: Polar Research
• Main Authors: Oriol Sacristán-Soriano, Carlos Angulo-Preckler, Jennifer Vázquez, Conxita Avila
• Format: Article in Journal/Newspaper
• Language: English
• Published: Norwegian Polar Institute 2017
• Subjects: Antibacterial activity; natural products; symbiosis; host–symbiont interactions; microbial ecology; geo; envir; Antarctic; Antarc*; Antarctica; Polar Research
• Online Access: https://doi.org/10.1080/17518369.2017.1390385; https://doaj.org/article/59de9cb128e1469cb8939444e6f7a8aa

The continental shelf of Antarctica harbours rich suspension-feeding macroinvertebrate communities that are continuously exposed to large populations of free-living microbes. To avoid settlement or fouling by undesirable microorganisms that could cause infection or collapse filter-feeding systems, these macroinvertebrates might regulate the epibiotic microbial mat through chemical interactions. In Antarctic chemical ecology, the antibacterial roles of natural products remain mostly unknown. A necessary first step is to identify organisms that produce compounds with potential ecological relevance. For that reason, we tested the crude organic extracts of 116 taxa of Antarctic benthic organisms for antibacterial activity against a panel of seven strains of marine bacteria. Nine out of 11 phyla tested had antibacterial properties. However, inhibitory activity was quite selective and species-specific. These patterns suggest that Antarctic benthic organisms may produce diverse bioactive metabolites with different antibacterial activities or, alternatively, those contrasting profiles may be shaped by environmental and biological interactions acting at a small spatial scale. The reasons of such selectivity remain to be further investigated and may contribute to the identification of bioactive compounds with pharmaceutical applications.