Alcohol dehydrogenase fermentation

H. Sakoda, T. Imanaka, Effect of amino acid substitutions at the active center on the activity of Bacillus stearothermophilus alcohol dehydrogenase, /. Ferment. Bioene. 1992, 73(5), 405-407. 

See also Alcoholic Fermentation, Alcohol Dehydrogenase, Fermentation, Anaerobic Glycolysis, see also here... 

Alcohol dehydrogenase (5) and leucine a-ketoglutarate transaminase (33,34) contribute to the development of aroma during black tea manufacturing. Polyphenol oxidase and peroxidase are essential to the formation of polyphenols unique to fermented teas. 

It is noteworthy, here, that one conunercial source of purified alcohol dehydrogenase is horse liver. There is a considerable quantity of this enzyme in horse liver. It is likely that alcohol arises from fermentation in the caecum of the high content of fibre present in the food of the horse. Hence its liver will be exposed chronically to high concentrations of alcohol, and the liver adapts by synthesising large quantities of the enzyme. 

Arnau J, Jorgensen F, Madsen SM, Vrang A, Israelsen H (1998) Cloning of the Lactococcus lactis adhE gene, encoding a multifunctional alcohol dehydrogenase, by complementation of a fermentative mutant of Escherichia coli. J Bacteriol 180 3049-3055... 

Marshall, V. M. and Cole, W. M. 1983. Threonine aldolase and alcohol dehydrogenase activities in Lactobacillus bulgaricus and Lactobacillus acidophilus and their contribution to flavour production in fermented foods. J. Dairy Res. 50, 375-379. 

Yeast contains two cytosolic alcohol dehydrogenase isoenzymes.66 Alcohol dehydrogenase I, present in large amounts in cells undergoing fermentation,... 

M. Niculescu, T. Erichsen, V. Sukharev, Z. Kerenyi, E. Csoregi and W. Schuhmann, Quinohemoprotein alcohol dehydrogenase-based reagentless amperometric biosensor for ethanol monitoring during wine fermentation, Anal. Chim. Acta, 463(1) (2002) 39-51. 

During the biotransformation of benzaldehyde by fermenting yeast (Scheme 1) to (R)-PAC the reduction of the benzaldehyde to benzyl alcohol is a serious problem, caused partially by the presence of alcohol dehydrogenases... 

Chiral alcohols are valuable products mainly as building blocks for pharmaceuticals or agro chemicals or as part of chiral catalysts. Cheap biotransformation methods for the selective reduction of particular ketone compounds are known for many years rather catalyzed by fermentation than with isolated enzymes. Products prepared with whole cells such as baker s yeast often lack high enantioselectivity and there were several attemps to use isolated enzymes. Resolution of racemates with hydrolases are known in some cases but very often the reduction of the prochiral ketone using alcohol dehydrogenases are much more attractive. 

Conversion to ethanol. In yeast and some other microorganisms under anaerobic conditions, the NAD+ required for the continuation of glycolysis is regenerated by a process called alcoholic fermentation. The pyruvate is converted to acetaldehyde (by pyruvate decarboxylase) and then to ethanol (by alcohol dehydrogenase), the latter reaction reoxidizing the NADH to NAD+ ... 

Although it is the least toxic alcohol, ethanol is still a poisonous substance. When someone is suffering from a mild case of ethanol poisoning, we say that he or she is intoxicated. Animals often consume food that has fermented and contains alcohol. Their bodies must detoxify any alcohol in the food to keep it from building up in the blood and poisoning the brain. To detoxify ethanol, the liver produces an enzyme called alcohol dehydrogenase (ADH). 

Yeast, a facultative anaerobe, uses alcoholic fermentation (Sec. 11.2) pyruvate decarboxylase catalyzes the conversion of pyruvate to acetaldehyde, and then alcohol dehydrogenase converts the acetaldehyde to ethyl alcohol and oxidizes NADH to NAD+. 

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