Experimental evidence of antimicrobial activity in Antarctic seaweeds: ecological role and antibiotic potential

Abstract Seaweeds contain a wide range of secondary metabolites which serve multiple functions, including chemical and ecological mediation with microorganisms. Moreover, owing to their diverse bioactivity, antibiotic properties, they show potential for human use. Nonetheless, the ecology seaweeds is not equally understood across different regions; example, Antarctic are among lesser studied groups. With aim improving our current understanding bioactivity seaweeds, we performed screening activity using crude extracts from 22 macroalgae species. Extractions were separating lipophilic hydrophilic fractions at natural concentrations. Antimicrobial assays disk diffusion method against seven bacteria pathogenic surrogates. Our results showed that red (especially Delisea pulchra ) inhibited larger number microorganisms compared brown more active than ones. Both types tested (Gram negative Gram positive) inhibited, especially by butanolic fractions, suggesting trend non-specific defence. However, Gram-negative one fungus greater resistance. study contributes evidence antimicrobial interactions between sympatric microorganisms, as well seaweed pharmacological applications.