A Gram-negative, non-spore-forming, ovoid to rod-shaped aerobic or microaerobic bacterium, strain 262-8 T , was isolated from a cavity within white rock collected in Antarctica. Strain 262-8 T grew at 5-30 6C (optimum 25 6C), at pH 6-8 (optimum approximately pH 7) and with 0.1-2.0 % (w/v) NaCl (optimum 0.5 % NaCl). The addition of tryptone or yeast extract was essential for growth. Strain 262-8 T was able to utilize organic compounds such as ribose, pyruvate and succinate in the presence of a low concentration of tryptone. Ubiquinone 10 was the major respiratory quinone. The major fatty acids were C 18 : 1 , C 16 : 0 and C 18 : 0 . The G+C content of the genomic DNA was 69.8 mol%. Comparative analyses of 16S rRNA gene sequences and physiological characteristics indicated that strain 262-8

A Gram-stain-negative, non-spore-forming, non-motile, irregularly circular, aerobic/microaerobic appendaged bacterium (strain 120-1 T ) was isolated from Naga-ike, one of the freshwater lakes in the Skarvsnes ice-free area of Antarctica. Strain 120-1 T grew between 5 and 35 6C, with optimum growth at 30 6C. The pH range for growth was between 6.0 and 9.0 (optimum of approximately pH 7.0). The range of NaCl concentration allowing growth of strain 120-1 T was between 0 and 5.0 %, with an optimum of 0.5-1.0 %. Strain 120-1 T was able to utilize organic compounds such as glucose, arabinose, gluconate, adipate and malate. Red colonies were formed on plate medium and the carotenoids were present in the cells. Ubiquinones Q-9 and Q-10 were the major respiratory quinones. The major cellular fatty acids were C 16 : 0 , C 18 : 1 v9c and C 18 : 1 v7c. The G+C content of the genomic DNA was 61.1 mol%.

Naturally occurring branched-chain polyamines induce a crosslinked meshwork structure in a giant DNA The Journal of Chemical Physics 145, 235103 (2016) We studied the changes in the higher-order structure of a megabase-size DNA (S120-1 DNA) under different spermidine (SPD) concentrations through single-molecule observations using fluorescence microscopy (FM) and atomic force microscopy (AFM). We examined the difference between the folding transitions in S120-1 DNA and sub-megabase-size DNA, T4 DNA (166 kbp). From FM observations, it is found that S120-1 DNA exhibits intra-chain segregation as the intermediate state of transition, in contrast to the all-or-none nature of the transition on T4 DNA. Large S120-1 DNA exhibits a folding transition at lower concentrations of SPD than T4 DNA. AFM observations showed that DNA segments become aligned in parallel on a two-dimensional surface as the SPD concentration increases and that highly intense parallel alignment is achieved just before the compaction. S120-1 DNA requires one-tenth the SPD concentration as that required by T4 DNA to achieve the same degree of parallel ordering. We theoretically discuss the cause of the parallel ordering near the transition into a fully compact state on a two-dimensional surface, and argue that such parallel ordering disappears in bulk solution.

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