特集−高圧力バイオサイエンス− Rev. High Pressure Sci. Technol. 9-3,183-190(1999) |
高圧力下で誘発される細胞膜の貫通孔 High Pressure-Induced Membrane Tunnel |
加藤倫子 林 力丸 Michiko KATO Rikimaru HAYASHI |
High pressure treatment of microbial cells
and plant and animal tissues at 100-400
MPa
solubilizes cellular compounds such
as metals,
amino acids, and proteins, permeates
extra-cellular
compounds such as salts into cells
and tissues,
and causes hemolysis. After the pressure
treatment, electron microscopic observation
of yeast cells and biochemical analysis
of
animal tissues reveal a significant
membrane
breakage of nuclei, lysosomes, and
vacuoles
in addition to light cell membrane
and cell
wall damage. To understand these observed
phenomena at the molecular level, we
studied
functional and structural changes of
the
membrane-bound Na+, K+-ATPase under
increasing
high pressure (in situ observation),
and
reached an interesting conclusion that
contact
faces of lipid and membrane-penetrating
protein
surfaces are reversibly separated to
produce
tunnels or holes at 100-250 MPa, followed
by disordered breakdown of the membrane
system
including protein denaturation at 300
MPa
or higher. This conclusion is well
supported
by the phase transition of the lipid
bilayer
membrane. [high pressure-treatment, membrane breakdown , membrane-bound Na+, K+-ATPase, high pressure-induced membrane hole] |
〒606-8502 京都市左京区北白川追分町 京都大学大学院農学研究科応用生命科学専攻 Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 |
特集−高圧力バイオサイエンス− Rev. High Pressure Sci. Technol. 9-3,191-198(1999) |
高圧力下で冷凍した食品のテクスチャーと微細構造 Texture and Structure of High-Pressure-Frozen Foods |
渕上 倫子 Michiko FUCHIGAMI |
To determine the effect of high-pressure-freezing
on quality, carrots and tofu (soybean curd)
were frozen at 100 MPa (ice I), 200 MPa (liquid
phase), 340 MPa (ice III), 400, 500, 600
MPa (ice V) or 700 MPa (ice VI) at ca. -20℃
then thawed at atmospheric pressure. The
texture and structure of these foods frozen
at 200 〜 400 MPa improved in comparison
to foods frozen at 0.1 MPa (frozen in freezers
at -20℃ , -30℃ or -80℃) or 100, 600 and
700 MPa. However, ice crystals were observed
even in tofu frozen at 200 MPa 〜400 MPa.
Therefore, tofu was also thawed at a high
pressure and then the pressure was reduced.
Texture and structure (pore size) of tofu
frozen at 200 〜400 MPa were the same as
for unfrozen tofu. This indicated that phase
transitions (ice VI → ice V→ice III →
liquid → ice I) occurred during reduction
of pressure at 20℃, during freezer storage
or while thawing at 0.1 MPa. Thus, high-pressure
freezing-thawing at 200 〜400 MPa was effective
in improving the quality of frozen foods. [high pressure, freezing, thawing, texture, carrot, pectin, tofu, electron microscope] |
〒719-1197 岡山県総社市窪木111 岡山県立大学保健福祉学部 Dept. of Nutritional Science, Faculty of Health & Welfare Science, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama-ken, 719-1197 |
特集−高圧力バイオサイエンス− Rev. High Pressure Sci. Technol. 9-3,199-204(1999) |
微生物の圧力ストレス応答とトレハロースの役割 High-Pressure Stress Response of Microbes and the Role of Trehalose in Their Behavior |
田村勝弘 Katsuhiro TAMURA |
Trehalose (α-D-Glucopyranosyl α-D-glucopyranoside)
is one of the disaccharides and exists widely
in animals, plants and bacteria. In this
article, the role of trehalose in microbial
cells was discussed from the point of view
of their stress response: synthesis of heat
shock proteins and trehalose, and the induction
of stress tolerance. Furthermore, an outline
of the behavior of microbes under high pressure
was also given. The concrete contents of
the article are (1) effects of trehalose
on thermotolerance of pressure-shocked yeast,
(2) effects of temperature and pressure on
the death rate of Lactobacillus casei and Escherichia coli, (3) properties and functions of trehalose,
(4) extreme barotolerance of tardigrade,
and (5) correlation of thermotolerance and
barotolerance of yeast and the mean number
of equatorial OH groups in sugar molecules.
[microbes, yeast, trehalose, heat shock, pressure shock, thermotolerance] |
〒770-8506 徳島市南常三島町 2-1 徳島大学工学部化学応用工学科 Department of Chemical Science and Technology, Faculty of Engineering, The University of Tokushima, Minamijosanjima-cho, Tokushima 770-8506 |
特集−高圧力バイオサイエンス− Rev. High Pressure Sci. Technol. 9-3,205-212(1999) |
深海微生物の加圧応答 Pressure Response in Deep-Sea Microorganisms |
加藤 千明 Chiaki Kato |
Several baro(piezo)-philic microorganisms
have been isolated from a deep-sea high hydrostatic
pressure environment in our laboratory. The
results of taxonomic studies showed that
all of the barophile isolates belonged to
Proteobacteria gamma-subgroup, and four novel
species were identified. The moderately barophilic
bacterium, Shewanella violacea strain DSS12 was one of them, and this strain
was able to grow from atmospheric pressure
(0.1 MPa) to 70 MPa conditions in the same
way. Molecular mechanisms of pressure-regulation
on gene expression in S. violacea were analyzed, and we identified particular
DNA binding proteins that might be essentially
important for pressure regulation. Atmospheric
pressure adapted Escherichia coli that belonged to the same gamma-subgroup
of the isolated barophilic species was also
studied and we could observe the positive
and negative effects on pressure regulation.
Finally, we observed that hyper-thermophilic
archaea could grow well under higher pressure
conditions at higher temperatures. These
results indicated that pressure could affect
microorganisms* survival in several ways
in such an environment. [baro(piezo)-philic bacteria, deep-sea, high pressure, gene expression, pressure-regulated genes, Escherichia coli, hyperthermophilic archaea] |
〒237-0061 横須賀市夏島町 2-15 海洋科学技術センター深海環境フロンティア The DEEPSTAR Group, Japan Marine Science and Technology Center, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan |
特集−高圧力バイオサイエンス− Rev. High Pressure Sci. Technol. 9-3,213-220(1999) |
高圧力下におけるリン脂質二重膜 Phospholipid Bilayer Membranes under High Pressure |
金品 昌志 松木 均 一森 勇人* Shoji KANESHINA Hitoshi MATSUKI Hayato ICHIMORI |
Pressure studies on the bilayer phase transitions
of phosphatidylcholines with various
acyl
chains are reviewed. Temperature-pressure
phase diagrams of lipid bilayer membranes
are shown. In addition to liquid crystal,
ripple gel, and lamellar gel phases;
the
presence of a pressure-induced gel
phase,
i. e., the interdigitated gel phase
was found.
The minimum pressure for the interdigitation
of lipid bilayers decreased with an
increase
in acyl chain length in a non-linear
manner.
Thermodynamic quantities for the main
transition
were non linear with respect to the
acyl
chain length. The effect of an unsaturated
acyl chain on the phase behavior was
also
described. [lipids, bilayer membrane, vesicle, phase transition, phase diagram, interdigitation, unsaturated lipid] |
〒770-8506 徳島市南常三島町2-1 徳島大学工学部生物工学科 Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506 *〒774-0017 徳島県阿南市見能林町 阿南工業高等専門学校 Anan College of Technology, Minobayashi-cho, Anan, Tokushima 774-0017 |
解説 Rev. High Pressure Sci. Technol. 9-3,221-226(1999) |
錯体の溶液内反応の研究に関する傾向 Recent High Pressure Kinetics of the Reactions of Metal Complexes in Solution |
石原 浩二 Koji ISHIHARA |
The first high pressure study on a fast inorganic
reaction was reported by Brower in
1968.
Since then, various high pressure apparatus
for the study of fast reactions in
solution,
such as high-pressure T-jump, P-jump,
NMR,
stopped-flow, etc., have been exploited
with
the increasing interest in the high
pressure
chemistry of fast inorganic reactions.
In
this review, after brief explanations
of
the apparatus and classification, the
relation
of activation volumes and complex formation
and solvent exchange mechanisms of
metal
ions classified by the Langford and
Gray
classification, which is assigned on
the
basis of kinetic data at ambient pressure,
is explained. Recent studies relevant
to
high pressure kinetics are also covered. [complex formation, solvent exchange, mechanism, activation volume, fast reaction, high pressure apparatus] |
〒169-8555 東京都新宿区大久保 3-4-1 早稲田大学理工学部化学科 Department of Chemistry, School of Science and Engineering, Waseda University, Okubo, Shinjuku-ku, Tokyo, 169-8555 Japan |
〒606-0805
京都市左京区下鴨森本町 15 (財)生産開発科学研究所内
日本高圧力学会事務局
Tel (075)721-0376 Fax (075)723-9629
koatsu@mbox.kyoto-inet.or.jp