Saccharomyces Marxianus will not hydrolyse maltose, but it does attack cane sugar and ferment the products of hydrolysis.
The glucose of commerce, which may be regarded as a mixture of grape sugar, maltose and dextrins, is prepared by hydrolysing starch by boiling with a dilute mineral acid.
Thus, a form termed Photobacterium phosphorescens by Beyerinck will absorb maltose, and will become luminous if that sugar is present, whereas P. Pflugeri is indifferent to maltose.
A yeast, which saccharifies starch, it is possible to tell whether maltose or levulose and fructose are formed; if the former, only those plates containing P. phosphorescens will become luminous; if the latter, only those containing P. Pflugeri.
The freshly-expressed yeast juice causes concentrated solutions of cane sugar, glucose, laevulose and maltose to ferment with the production of alcohol and carbon dioxide, but not milk-sugar and mannose.