The fermentation of galactose and galactose-1-phosphate

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Abstract
With maceration extract, both glucose-1-phosphate and galactose-1-phosphate showed the characteristics of natural hexosemonophosphates, namely, the 3 periods of induction, rapid fermentation, and slow fermentation. While the non-phosphorylated hexoses produced about 50% of the calculated quantity of CO2 during the period of rapid fermentation, the esters produced only 25-30% during the same period. The fermentation rates of the esters were so similar as to suggest an enzymatic equilibrium between them. So far it has not been possible to supply direct exptl. proof for this suggestion. A tentative hypothesis of galactose fermentation is formulated: it is assumed that during the adaptation of Saccharomyces cerevisiae to ferment galactose, 2 new enzymes are formed, one which phosphorylates galactose at C1 and another which converts galactose-1-phosphate to Robison ester, probably by way of glucose-1-phosphate.