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Titre :
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Adaptation of microorganisms and their transport systems to high temperatures
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Auteurs :
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B. Tolner ;
B. Poolman ;
W. Konings
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Type de document :
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article/chapitre/communication
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Année de publication :
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1997
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Format :
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p. 423-428
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Langues:
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= Anglais
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Catégories :
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MICROBIOLOGIE
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Mots-clés:
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MICROORGANISME
;
MICROORGANISME PATHOGENE
;
THERMOSTABILITE
;
THERMOPHILIE
;
LIPIDE
;
MEMBRANE
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Résumé :
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Growth of Bacteria and Archaea has been observed at temperatures up to 95 and 110 °C, respectively. These thermophiles are adapted to environments of high temperature by changes in the membrane lipid composition, higher thermostabilities of the (membrane) proteins, higher turnover rates of the energy transducing enzymes, and/or the (exclusive) use of sodium-ions rather than protons as coupling ion in energy transduction. The proton permeability of the cytoplasmic membrane of bacteria and archaea was observed to increase with the temperature. This increased proton permeability limits the maximum temperature of growth of bacteria. Higher growth temperatures can be reached by an increased proton pumping activity by using the less permeable sodium ions as coupling ions or by changing the lipid composition of the cytoplasmic membrane. The Na+/H+/glutamate transport proteins of the thermophiles Bacillus stearothermophilus (GltT(Bc)) and Bacillus caldotenax (GltT(Bc)) were studied extensively. These transportproteins have unique features.
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Source :
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Comparative Biochemistry and Physiology A - Physiology, vol.118 A, n°3
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