Alcohol Dehydrogenases and their Physiological Functions in Hyperthermophiles
Kesen Ma and Ching Tse
from: Thermophilic Microorganisms (Edited by: Fu-Li Li). Caister Academic Press, U.K. (2015) Pages: 141-178.
Alcohol dehydrogenases (ADHs) are enzymes that catalyze the inter-conversion of alcohols to corresponding aldehydes/ketones with the concomitant reduction of NAD+ or NADP+. NAD(P)-dependent ADHs from mesophilic and thermophilic bacteria/archaea are orderly clustered as three distinct groups which are zinc-dependent, metal-free short-chain, and iron-containing/activated. ADHs from extreme thermophiles and hyperthermophiles are highly thermostable with optimal temperature of 65°C and above, which is advantageous for industrial applications. To date, ADHs from 10 extreme thermophiles and 15 hyperthermophiles are well characterized with respects to their thermostabilities and catalytic activities. This review aims mainly to provide a review of the most common use of ADHs, physiological functions of ADHs in hyperthermophiles and their potential applications in biotechnology. Relevant aspects including the principal procedures for purification, biophysical, biochemical and catalytic properties of ADHs from extreme thermophiles and hyperthermophiles are also discussed. These information will provide further insight into the importance of the ubiquitously expressed ADHs in microorganisms, particularly hyperthermophiles and their prospective contributions to advancing industrial processes read more ...