Isolation and Identification of Polar Bacteria from Arctic and Antarctic Regions

Abstract

We isolated 13 strains of polar bacteria from various materials such as sea water, fresh water, biofilm and sediment, that were collected from areas around the Korean Arctic Research Station located at Ny-Alsund, Svalbard, Norway (79°N, 12°E) in August, 2005 and around the King Sejong Korean Antarctic Research Station located at King George Island (62°S, 58°W) from November to December, 2005. Among them, four strains from Arctic region were identified as Polaribacter irgensii, Psychromonas arctica, Shewanella frigidimarina, and Shewanella pacifica, the rest nine strains from Antarctic region as Chryseobacterium balustinum, Flavobacterium psychrophilum, Herbaspirillum autotrophicum, Leifsonia rubra, Pedobacter koreensis, Psychrobacter arcticus, Psychrobacter glacincola, Rhodoferax ferrireducens, and Sejongia antarctic. To examine optimum and range of growing temperature for these bacterial strains, we measured average diameter of colonies grown at various temperature ranging from 4℃ to 37℃. The optimal growth temperature for most strains was around 10 to 15℃ except for H. autotrophicum growing normally at 4℃. A phylogenetic analysis based on 16S rRNA gene sequences was performed with isolated 13 bacterial strains using the neighbor-joining methods. These results and polar bacterial strains from this study can be used for studying molecular mechanisms of organisms adapted to cold environments.