Yeast catalyst

Use Fertilizer, explosives especially as prills/oil mixture, pyrotechnics, herbicides and insecticides, manufacture of nitrous oxide, absorbent for nitrogen oxides, ingredient of freezing mixtures, oxidizer in solid rocket propellants, nutrient for antibiotics and yeast, catalyst. 

Uses Fertilizer explosives pyrotechnics herbicides/insecticides mfg. of nitrous oxide absorbent for nitrogen oxides ingred. of freezing mixtures oxidizing agent in solid rocket propellants nutrient for antibiotics and yeast catalyst in paper/paperboard in contact with dry food... 

Grain that is usable as food or feed is an expensive substrate for this fermentation process. A cheaper substrate might be some source of cellulose such as wood or agricultural waste. This, however, requires hydrolysis of cellulose to yield glucose. Such a process was used in Germany during World War II to produce yeast as a protein substitute. Another process for the hydrolysis of wood, developed by the U.S. Forest Products Laboratory, Madison, Wisconsin, uses mineral acid as a catalyst. This hydrolysis industry is very large in the former Soviet Union but it is not commercial elsewhere. 

The (ZZ-ephedrine was resolved into its components by the use of d-and Z-mandelic acids. In 1921 Neuberg and Hirsch showed that benz-aldehyde was reduced by yeast, fermenting in suerose or glueose solution to benzyl aleohol and a phenylpropanolone, which proved to be Z-Ph. CHOH. CO. CH3. This ean be simultaneously, or consecutively, eondensed with methylamine and then eonverted to Z-ephedrine by reduction, e.g., with aluminium amalgam in moist ether, or by hydrogen in presenee of platinic oxide as catalyst (Knoll, Hildebrant and Klavehn ). 

So far only two groups have reported details of the use of ionic liquids with wholecell systems (Entries 3 and 4) [31, 32]. In both cases, [BMIM][PF(3] was used in a two-phase system as substrate reservoir and/or for in situ removal of the product formed, thereby increasing the catalyst productivity. Scheme 8.3-1 shows the reduction of ketones with bakers yeast in the [BMIM][PF(3]/water system. 

Biological catalysts are called enzymes. Nearly every step of the breakdown of a complex molecule to a series of smaller ones, within living cells, is catalyzed by specific enzymes. For instance, when acetaldehyde is reduced in yeast... 

HE = heterogeneous catalyst, HO = homogeneous catalyst, E = enzyme, Y = yeast. 

In an fermentation process of a solution containing sucrose, the enzyme in-vertase, present in yeast, acts as a catalyst to convert sucrose into a 1 1 mixture of glucose and fructose. Thus, sucrose is a disaccharide that hydrolyzes in the presence of certain bacteria to yield glucose and fructose. The ether linkage in sucrose is broken to yield two alcohols ... 

Dienys, G., Jarmalavicius, S., Budriene, S. et al. (2003) Alcohol oxidase from the yeast Pichia pastoris — a potential catalyst for organic synthesis. Journal of Molecular Catalysis B-Enzymatic, 21 (1-2), 47—49. 

Ethanol is also produced by the fermentation of sugars such as glucose. The reaction is carried out at about 35°C in the presence of yeast, which contains an enzyme (biological catalyst) called zymase. 

Several catalysts are used in the field of microbial reductions. The common features of these catalysts are the high selectivity and their use only on a laboratorial scale. They are applied, for example, in the stereoselective synthesis of pharmaceutical intermediates. The reductions are exclusively selective either in the hydrogenation of the C=C double bond or in that of other reducible groups. One of the most widely used catalysts is baker s yeast. In the following hydrogenations, which are catalyzed by Saccharomyces cerevisiae, high enantioselectivities were achieved (equations 35-38)105-108. 

The use of the reversion spectroscope enabled the position of the absorption bands to be determined accurately and to be conclusively distinguished from hemoglobin and myoglobin. It became clear that there were three different intracellular respiratory catalysts— cytochromes a,b,c—common to animals, bacteria, yeast and higher plants. In 1925 a preliminary scheme for the passage of O2 from blood to tissue was proposed ... 

Eventually, scientists proved that fermentation did not require whole cells of yeast. Fermentation could still occur if non-living extracts of yeast were present. Through further study and experimentation, the important component in the yeast extract was identified as an enzyme. If earlier scientists had considered Fulhame s ideas on catalysts, they might have arrived at the truth about enzymes sooner ... 

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