• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.401-411
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• 1995

Flavobacterium spp., Pseudomonas spp., and Vibrio spp. were isolated from samples(sediments) of Sagami Bay and Suruga Bay(in Japan) at 810-4,000m in depth. Among isolated strains, Vibvio sp.-86 and sp.-87 strains were identified as barophilic and psychrophilic ones. They grew in 400 atm and showed best growth at 100 atm. Marine bacteria grown at 400 atm were long rod shape and 30 to 50times longer than those grown at 1 atm. which were short rod shape and formed flocks (aggregates). Vibrio sp,-86 strain grew at $5-37^{\circ}C\;and\;0,5-9.0\%\;NaCl\;(3.0\%\;of\;optimum\;concentration),$ while Vibrio sp.-87 strain grew at $1-7\%\;NaCl\;(2,0\%\;of\;optimum\;concentration).$ The fatty acid compositions of Vibrio sp.-86 strain grown at 1 atm were $C_{20}-C_{22:0},\;C_{l6:1},\;and\;C_{16:0}$ in the order of their abundance and at 400 atm the order were $C_{18:1},\;C_{18:0},\;and\;C_{20}-C_{22}$, whereas those of Vibrio sp.-87 strain at 1 atm were $C_{6:1},\;C_{14:1},\;and\;C_{20}-C_{22}$ and at 400 atm the order were $C_{14:1},\;C_{12:0},\;and\;C_{16:1}$ The amino acids compositon of Vibrio sp.-86 strain grown at 1 atm were abundant in the order of aspartic acid, methionine, and glutamic acid and those at 400 atm were abundant in the order of methionine, glutamic acid, and aspartic acid. The amino acids composition of Vibrio sp.-87 strain grwon at 1 atm were abundant in the order of methionine, glutamic acid, and aspartic acid and those at 400 atm were abundant in the order of methionine, glutamic acid, and isoleucine.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.80-82
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• 2007

We have isolated numerous cold deep-sea adapted microorganisms (piezophilic, formerly referred to as "barophilic" bacteria) using deep-sea research submersibles. Many of the isolates are novel psychrophilic bacteria, and we have identified several new piezophilic species, i.e., Photobacterium profundum, Shewanella violacea, Moritella japonica, Moritella yayanosii, Psychromonas kaikoi, and Colwellia piezophila. These piezophiles are involving to five genera in gamma-Proteobacteria subgroup and produce significant amounts of unsaturated fatty acids in their cell membrane fractions to maintain the membrane fluidity in cold and high-pressure environments. Piezophilic microorganisms have been identified in many deep-sea bottoms of many of the world oceans. Therefore, these microbes are well distributed on our planet. One of the isolated deep-sea piezophiles, Shewanella violacea strain DSS12 is a psychrophilic, moderately piezophilic bacterium from a sediment sample collected at the Ryukyu Trench (depth: 5,110 m), which grows optimally at 30 MPa and $8^{\circ}C$ but also grows at atmospheric pressure (0.1 MPa) and $8^{\circ}C$. We have examined this strain to elucidate the molecular basis for gene regulation at different pressure conditions because this strain is useful as a model bacterium for comparing the various features of bacterial physiology under pressure conditions. In addition, we completed the sequencing of the entire genome of this piezophilic bacterium and we expect that many biotechnologically useful genes will be identified from the genome information.