Ester formation by brewers' yeast during sugar fermentation.

Parameters affecting ethyl ester production by Saccharomyces cerevisiae during fermentation.

Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the influence of several fermentation variables. A higher level of ...

Choline Kinase from Brewers’ Yeast

Choline kinase was purified approximately 300-fold, in 5% yield, from an autolysate of dried brewers’ yeast. A molecular weight of 67,000 was estimated using a Stokes radius of 33 A, as determined by Sephadex G-200 chromatography. An s~,,,~ of 4.8 S was obtained by sucrose density gradient centrifugation. Enzyme activity was diminished by sulfhydryl inhibitors and stabilized by the presence of ...

Pseudoporphyria associated with consumption of brewers' yeast.

A case of pseudoporphyria associated with excessive consumption of brewers ' yeast was studied. Detailed analysis of the yeast tablets by high performance liquid chromatography showed the presence of dicarboxylic deuteroporphyrin , mesoporphyrin, and protoporphyrin; coproporphyrin I and III isomers; and uroporphyrin I and III isomers. The faecal porphyrin concentration of the patient taking yea...

Utilization of Wort Fatty Acids by Yeast During Fermentation

Uniformly labeled C-palmitic, oleic, and linoleic acids were used individually to trace wort fatty acids in ale yeast fermentations. Fatty acids extracted from the resulting beers were analyzed by gas-liquid chromatography with concurrent radioactivity monitoring. Lipid components extracted from the harvested yeast were separated by thin-layer chromatography, and the fatty acyl residues of thes...

Fermentation of Sugar Acids by Bacteria.