The Carbohydrate and Fat Metabolism of Yeast

AFTER yeast has been incubated in a well-oxygenated solution of glucose, fructose or sucrose, its fat-content becomes very considerably increased. If the solution in which the yeast is incubated contains not only sugar but also a mixture of alkali phosphates, the total amount of lipoid (ether-soluble matter) which can be extracted from the yeast after its incubation is double that which can be extracted from the same amount of yeast incubated in a similar sugar solution from which phosphates are absent After incubation in the sugar-phosphate medium the phosphate-content of the yeast is also greatly increased, the increase depending on the concentration of the sugar in the medium. After yeast has been incubated in a solution containing only alkali phosphates, no increase in the phosphate-content of the yeast is observed [Smedley-MacLean and Hoffert, 1924].