Diversity of pigmented Gram-positive bacteria associated with marine macroalgae from Antarctica

• Published in: FEMS Microbiology Letters
• Main Authors: Leiva, Sergio, Alvarado, Pamela, Huang, Ying, Wang, Jian, Garrido, Ignacio
• Format: Text
• Language: English
• Published: Oxford University Press 2015
• Subjects: Environmental Microbiology; Antarctic; King George Island; South Shetland Islands; Antarc*; Antarctica; antartic*
• Online Access: http://femsle.oxfordjournals.org/cgi/content/short/362/24/fnv206; https://doi.org/10.1093/femsle/fnv206

Little is known about the diversity and roles of Gram-positive and pigmented bacteria in Antarctic environments, especially those associated with marine macroorganisms. This work is the first study about the diversity and antimicrobial activity of culturable pigmented Gram-positive bacteria associated with marine Antarctic macroalgae. A total of 31 pigmented Gram-positive strains were isolated from the surface of six species of macroalgae collected in the King George Island, South Shetland Islands. On the basis of 16S rRNA gene sequence similarities ≥99%, 18 phylotypes were defined, which were clustered into 11 genera of Actinobacteria ( Agrococcus, Arthrobacter, Brachybacterium, Citricoccus, Kocuria, Labedella, Microbacterium, Micrococcus, Rhodococcus, Salinibacterium and Sanguibacter ) and one genus of the Firmicutes ( Staphylococcus ). It was found that five isolates displayed antimicrobial activity against a set of macroalgae-associated bacteria. The active isolates were phylogenetically related to Agrococcus baldri, Brachybacterium rhamnosum, Citricoccus zhacaiensis and Kocuria palustris . The results indicate that a diverse community of pigmented Gram-positive bacteria is associated with Antartic macroalgae and suggest its potential as a promising source of antimicrobial and pigmented natural compounds.