Pichia alcohol fermentation

Laplace JM, Delgenes JP, Moletta R, Navarro JM. (1991). Alcoholic fermentation of glucose and xylose by Pichia stipitis, Candida shehatae, Saccharomyces cerevisiae and Zymomonas mobilis oxygen requirement as a key factor. Appl Microbiol Biotechnol, 36, 158-162. 

Fusel oil formation varies with yeast strain, temperature of fermentation, pH, nutritional status, suspended solids level, and oxygen concentration of juice/must. Under oxidative conditions as would occur before the onset of alcoholic fermentation, or in cases of stuck fermentation, Pichia, Hansenula, and Candida may produce substantial quantities of fusel alcohols from fermentable sugars. The fusel alcohol, 2-phenylethanol (arising from 2-phenylalanine), has the unmistakable odor of roses and is also... 

Other aldehydes/alcohols can be produced following the same principles. For production of Cio-lactone, however, a different strategy has to be followed after the formation of the hydroperoxide. It involves the fermentative -oxidation of the hydroperoxide intermediate by the yeast Pichia etchellsii, and the subsequent cyclization of 5-hydroxydecanoic add to the corresponding S(-)-8-decalactone. TTae routes to (Z3)-hexenol and S(-)-6-decalactone are depicted in Fig. 7.11. 

Alcohols Lower alcohols have been measured with alcohol oxidase (EC 1.1.3.13) from Candida boidinii or Pichia pastoris. The latter is available with a higher specific activity and has a somewhat different substrate specificity. Coimmobilization with catalase increases the stability of the enzyme column to several months with an operating range of 0.005-1 mmol 1 (0.5 ml samples) using 0.1 mol 1 sodium phosphate, pH 7.0, as the buffer. This assay is useful for the determination of ethanol in samples from beverages, blood, and for monitoring fermentation. 

The ability of yeasts such as baker s yeast Saccharomyces cerevisiae) was utilized extensively by chemists to reduce carbonyl compounds to alcohols [70,71]. 2,2-Dimethylcy-clohexane-l,3-dione (56) can be reduced with fermenting baker s yeast to give the (5)-hydroxy ketone 5 (Fig. 27), which was employed extensively in terpene synthesis as shown in Fig. 5 [23]. Diastereo- and enantioselective reduction of 57 Wiih Pichia terricola KI 0117 yielded 6 (Fig. 27) [35], which was converted to both (+)-JH I [35] and (—)-JH I [72,73] (Fig. 6). Reduction of 57 with baker s yeast was nondiastereoselective [35]. 

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