Biocatalysis Near and Above 100 °C

Enzymes are typically labile molecules and thus are adversely affected when exposed to any type of extreme conditions. As such, biocatalysis, in either a physiological or biotechnological sense, has usually constrained to a rather narrow range of temperature, pH, pressure, ionic strength and to an aqueous environment. In fact, given its physiological role, and the need at times to regulate enzymatic activity, this is appropriate. Unfortunately, the use of biological catalysts for technological purpose necessitates that enzymes be stable and functional in nonphysiological environments. The challenge then is to either isolate enzymes more suitable for a particular application or be able to modify existing enzymes systematically to improve their stability and/or function. While a number of thermostable enzymes have been studied previously, the focus here is on thermostable enzymes produced by high temperature microorganisms.