ARTHROBACTER, BRACHYBACTERIUM AND PLANOCOCCUS ISOLATES IDENTIFIED FROM ANTARCTIC SEA-ICE BRINE - DESCRIPTION OF PLANOCOCCUS-MCMEEKINII, SP.NOV

Three facultative psychrophilic Gram-positive bacterial strains were i solated from brine samples from the sea ice community in Antarctica. A ll strains were coccoid to rod-shaped and exhibited broad salinity and temperature ranges for growth. The three strains were subjected to 16 S rDNA sequencing and subsequent phylogenetic analysis. All possess un ique 16S rDNA sequences indicating they are new, previously unreported organisms. Phylogenetic analyses coupled with phenotypic characteriza tion indicated that one of the strains is most closely related to the low mol% G + C genus Planococcus for which a new species, P. mcmeekini i, is proposed. The two other strains are members of the high mol% G C Grampositive bacteria and most closely related to the genera Arthro bacter and Brachybacterium. This study reports the first phylogenetic evidence that Gram-positive bacteria reside in the marine sea ice brin e.