Science and Education Publishing Journal of Applied & Environmental Microbiology 2 6 2014 10 30 Bacterial Diversity in Sea Ice from the Southern Ocean and the Sea of Okhotsk 266 272 EN Torahiko Okubo Yuika Tosaka Toyotaka Sato Masaru Usui Chie Nakajima Yasuhiko Suzuki Satoshi Imura Yutaka Tamura Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan JAEM2014261 10.12691/jaem-2-6-1 2014 10 08 2014 10 23 2014 10 30 In order to reveal the diversity of sea ice bacterial communities in polar and sub-polar regions, we investigated 2 drifting ice floes, one from the Australian side of the Southern Ocean and the other from the Sea of Okhotsk. We extracted bacterial DNA from sea ice and constructed 221 16S rDNA clone libraries including 109 clones from the Antarctic sea ice and 112 from the Okhotsk sea ice. The phylogenetic analysis of 16S rDNA sequences showed that Roseobacter and Sulfitobacter (Alphaproteobacteria), Psychrobacter, Halomonas, and Pseudoalteromonas (Gammaproteobacteria) were frequent in the Antarctic sea ice; Colwellia, Psychromonas, and Glaciecola (Gammaproteobacteria) and Polaribacter (Bacteroidetes) were major genera in the Okhotsk sea ice. While Alphaproteobacteria and Gammaproteobacteria were abundant in both samples, Bacteroidetes were detected only in the Okhotsk sea ice. Comparing the bacterial diversity of our samples with that of other studies, bacterial communities in sea ice were similar to one another at the phylum level, whereas their populations were quite different at the genus level. We also tried to detect antimicrobial and heavy metal resistance genes in our samples but didn't identified. Our results provide additional information about the bacterial communities in sea ice.