Psychrophilic Enzymes: Cool Responses to Chilly Problems
Most of the biotopes on Earth are permanently exposed to low temperatures. This includes the Antarctic continent, the Arctic ice floe, the permafrost, the mountain and glacier regions, and the deep-sea waters, the latter covering 70% of the planet surface. If a psychrophile is defined as an organism living permanently at temperatures close to the freezing point of water, in thermal equilibrium with the medium, this definition encompasses a large range of species from Bacteria, Archaea, and Eukaryotes. This aspect underlines that psychrophiles are numerous, taxonomically diverse, and have a widespread distribution. In these organisms, low temperatures are essential for sustained cell metabolism. Some psychrophilic bacteria grown at 4°C have doubling times close to that of Escherichia coliat 37°C. Such deep adaptation of course requires a vast array of metabolic and structural adjustments at nearly all organization levels of the cell, which begins to be understood thanks...
KeywordsThermophilic Protein Thermophilic Enzyme Psychrophilic Enzyme Mesophilic Enzyme Psychrophilic Protein
Research at the author’s laboratory was supported by the European Union, the Région wallonne (Belgium), the Fonds National de la Recherche Scientifique (Belgium), and the University of Liège. The facilities offered by the Institut Polaire Français are also acknowledged.
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