Alcoholic fermentation Candida

Once the lactic add and alcohol fermentation is complete, the moromi is aged until its moldy odor has disappeared. During this portion of the aging period other flavor molecules, particularly 4-ethylguaiacol and 4-ethylphenol are added to the moromi by Candida versatilis (4), These compounds are the major components contributing to the flavor of soy sauce. The entire moromi process is completed in about six months. 

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... 

Mutation. For industrial appHcations, mutations are induced by x-rays, uv irradiation or chemicals (iiitrosoguanidine, EMS, MMS, etc). Mutant selections based on amino acid or nucleotide base analogue resistance or treatment with Nystatin or 2-deoxyglucose to select auxotrophs or temperature-sensitive mutations are easily carried out. Examples of useful mutants are strains of Candida membranefaciens, which produce L-threonine Hansenu/a anomala, which produces tryptophan or strains of Candida lipolytica that produce citric acid. An auxotrophic mutant of S. cerevisiae that requires leucine for growth has been produced for use in wine fermentations (see also Wine). This yeast produces only minimal quantities of isoamyl alcohol, a fusel oil fraction derived from leucine by the Ehrlich reaction (10,11). A mutant strain of bakers yeast with cold-sensitive metaboHsm shows increased stabiUty and has been marketed in Japan for use in doughs stored in the refrigerator (12). 

Forest Products Laboratory have discovered a xylose-fermenting yeast (Candida tropicalis). Thus it now is possible to convert all wood sugars to ethyl alcohol with a combination of yeasts. Isolation of the specific enzymes and genetic engineering of the enzymes could dramatically improve the efficiency of this conversion. 

Carbohydrase (Candida pseudotropicalis) Produced as an off white to tan, amorphous powder or a liquid by controlled fermentation using Candida pseudotropicalis. Soluble in water (the solution is usually light yellow to dark brown) but insoluble in alcohol, in chloroform, and in ether. Major active principle lactase. Typical applications used in the manufacture of candy and ice cream and in the modification of dairy products. 

Employing L-ascorbate oxidase, vitamin C (ascrobic acid) was determined in food samples between 0.05-0.6 mM [44]. In order to measure ethanol in beverages and blood samples, alcohol oxidase from Candida boidinii had been employed. Linearity was obtained between 0.01 and 1 mM. These measurements were also found to be useful in monitoring fermentation [47,48]. 

Low-alcohol wines are affected by flor and a bloom develops on the wine s surface that is in contact with air. This bloom consists of a strain of yeast (Candida mycoderma) with a high respiratory capacity, but practically no fermentation activity, so it does not affect sugars. The main transformation caused by Candida mycoderma is the oxidation of ethanol into ethanal. This reaction may continue until the ethanol has... 

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