Thermophilic enzymes and their biotechnological potential

The ability of many microorganisms to grow at high temperatures has held a particular fascination for microbiologists and biochemists since a long time. As any of their cellular components, their proteins are inherently more stable to heat than those of conventional organisms. This thermal stability is not due to any specific characteristic, but results a consequence of various changes which contribute to the whole stability of the protein in an additive manner. These enzymes are not only more thermostable, but also more resistant to chemical agents than their mesophilic homologous, what makes them extremely interesting for industrial processes. Despite this, most of the enzymes used at present in industrial processes have been isolated from mesophiles due to the limited knowledge and difficulties to grow thermophiles in high scale. The objective of this review is to consider briefly the importance of the thermostability in order to apply enzymes in the industry, and to overview the most recent advances in the identification of new thermophilic organisms and enzymes. Furthermore, the recent development of genetic model systems for moderate and extreme thermophiles are referred.