The Cultivable Microbiota Associated with Four Antarctic Macroalgae

Marine macroalgae are suitable surfaces for bacterial colonization; in fact, this microbiota is important to the cycling of organic material from algal origin. We describe the cultivable microbiota associated with four endemic Antarctic macroalgae: Palmariadecipiens, Himantothallus grandifolius, Desmarestia antarctica, and Ascoseira mirabilis. Among the bacterial colonies obtained on marine agar 71.4% were affiliated to Proteobacteria, 20% to Firmicutes, and 8.6% to Bacteroidetes. Pseudoalteromonas was the only genus present in all samples; otherwise, each macroalga presented a unique microbiota, which was distinct from macroalgae from northern oceans. These results indicated a species-specific interaction between Antarctic macroalgae and its surface microbiota.