These investigators regarded yeast as a plant, and Meyer gave to the germs the systematic name of "Saccharomyces" (sugar fungus).
Saccharomyces Marxianus will not hydrolyse maltose, but it does attack cane sugar and ferment the products of hydrolysis.
It is supposed by some that Saccharomyces is a very degraded Ascomycete, in which the Torula condition has become fixed.
Of the greatest importance is the alcoholic fermentation brought about by yeast cells (Saccharomyces cerevisiae seu vini); this follows the equation CH120 6 =2C 2 H 6 0+2CO 2, Pasteur considering 94 to 95% of the sugar to be so changed.
The inactive mixture may be resolved into its active components by fractional crystallization of the cinchonine salt, when the salt of the dextro modification separates first; or the ammonium salt may be fermented by Penicillium glaucum, when the laevo form is destroyed and the dextro form remains untouched; on the other' hand, Saccharomyces ellipsoideus destroys the dextro form, but does not touch the laevo form.
About fifty species of Saccharomyces are described more or less completely, but since many of these cannot be distinguished by the microscope, and some have been found to develop physiological races or varieties under special conditions of - ?u growth, the limits are still far too ill-defined for complete ep botanical treatment of the genus.
At the same time there are strong grounds for insisting on the resemblances between Endomyces, a hyphal fungus bearing yeast-like asci, and such a form as Saccharomyces anomalus.