Vitamin C Maintenance against Cell Growth Arrest and Reactive Oxygen Species Accumulation in the Presence of Redox Molecular Chaperone Gene.

Chromosome damage combined with defective recombinase activity renders cells inviable, owing to deficient double-strand break repair. Despite this, cells grow well under either DNA damage response (SOS) conditions or catalase medium supplementation. Catalase treatments reduce intracellular reactive oxygen species (ROS) levels, suggesting that cells are susceptible to not only chronic chromosome damage but also ROS.

Reactive oxygen species accumulation is synchronised with growth inhibition of temperature-sensitive recAts polA Escherichia coli.

When combined with recombinase defects, chromosome breakage and double-strand break repair deficiencies render cells inviable. However, cells are viable when an SOS response occurs in recAts polA cells in Escherichia coli. Here, we aimed to elucidate the underlying mechanisms of this process.

Vegetative and reproductive growth of Arabidopsis under microgravity conditions in space.

We have performed a seed-to-seed experiment in the cell biology experiment facility (CBEF) installed in the Kibo (Japanese Experiment Module) in the International Space Station. The CBEF has a 1 × g compartment on a centrifuge and a microgravity compartment, to investigate the effects of microgravity on the vegetative and reproductive growth of Arabidopsis thaliana (L.) Heynh.

Alteromonas gracilis sp. nov., a marine polysaccharide-producing bacterium.

A novel exopolysaccharide-producing bacterium, designated strain 9a2(T), was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase- and catalase-positive, and required NaCl for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile consisted mainly of C16 : 1ω7c, C18 : 1ω9c and C16 : 0.

Psychrobacter oceani sp. nov., isolated from marine sediment.

A novel marine bacterium, designated strain 4k5(T), was isolated from a sediment sample of the Pacific Ocean. The strain was Gram-stain-negative, strictly aerobic, non-motile, oxidase-positive and catalase-positive and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone 8 (Q-8), and its cellular fatty acid profile consisted mainly of C18 : 1v9c (71.

Pseudoalteromonas shioyasakiensis sp. nov., a marine polysaccharide-producing bacterium.

A novel exopolysaccharide-producing bacterium, designated strain SE3(T), was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase-positive and catalase-positive, and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile mainly consisted of C16 : 1ω7c, C16 : 0 and C18 : 1ω7c.

Pseudoalteromonas arabiensis sp. nov., a marine polysaccharide-producing bacterium.

A novel exopolysaccharide-producing bacterium, designated strain k53(T), was isolated from sediment from the Arabia Sea, Indian Ocean. The strain was Gram-negative, motile, strictly aerobic, oxidase-positive and catalase-positive, and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile mainly consisted of C16 : 1ω7c, C16 : 0 and C18 : 1ω7c.

Effects of ultraviolet-B irradiation on the cuticular wax of cucumber (Cucumis sativus) cotyledons.

Cucumber seedlings were grown under three doses of supplemental ultraviolet-B (UV-B) irradiation to examine the effects on the surface structure of the cotyledons. Medium and high doses of irradiation induced glazing (formation of translucent, glossy layers) on the adaxial surfaces of cotyledons, especially those exposed to a high dose of UV-B. Observation with a scanning electron microscope revealed that the adaxial surfaces of cotyledons exposed to a medium dose of UV-B and controls became rough in appearance, but unevenness of the surface was not apparent in cotyledons irradiated with a high dose of UV-B.

Glaciecola chathamensis sp. nov., a novel marine polysaccharide-producing bacterium.

Two novel exopolysaccharide-producing bacteria, strains S18K6(T) and S18K5, were isolated from Pacific Ocean sediment. The isolates were Gram-negative, motile, strictly aerobic chemoheterotrophic bacteria. The DNA G+C contents of strains S18K6(T) and S18K5 were 44.

Optical microscopy of Arabidopsis seedlings fixed in non-fresh FAA using Kennedy Fixation Tubes.

Samples will be kept in non-fresh fixative for longer period than usual in Kennedy Space Center Fixation Tubes (KFT) when they will be fixed for microscopy in the International Space Station (ISS). It is necessary to examine characteristics of samples prepared under such conditions and to improve preservation of the samples. In this study, morphology of Arabidopsis tissues prepared under such conditions was examined under a light microscope.