MICRO-ORGANISMS. 137 
older known enzymes, such as rennet, diastase, and pepsin. 
Indeed, at one time, after the discovery of zymase, there was 
much discussion as to whether alcoholic fermentation was 
the work of an enzyme or of diffused protoplasm ; it is now 
accepted that it is really done by the former. The micro 
organisms may secrete many ferments; for example, yeast 
has been shown to produce at least five. It can convert 
starch to maltose by means of a diastase; it can invert cane- 
sugar by its invertase; maltose is changed to glucose by 
glucase; glucose is fermented to alcohol by zymase; and, 
finally, albumimoids are digested by a proteolase. 
Moulds in the Aleoholic Fermentation. 
Undoubtedly the most important fermentation from an 
economic point of view is the alcoholic; and perhaps the 
oldest fermentation of all, the lactic, comes next. In the 
Western world, the yeast-plant as a producer of alcohol 
holds sway; but within the last few years moulds from the 
East have been gradually introduced, in some cases to aid 
the yeast, in others to displace it; and, in all cases, chietly 
to dispense with the expensive malt. 
It is a matter of common knowledge that the steps in the 
process of making alcohol are starch, maltose, glucose, 
alconol, and sometimes saccharose, glucose, alecho!. Theactive 
“-ases”” in effecting these changes are diastase, glucase, 
zymase, and invertase, pymase. Instead of using malt or a 
mixture of malt and grains, such as rye, for the production 
of fermentable sugar, a cheaper cereal, rice, is sometimes 
infected with the mycelia of Aspergillus oryzae, a mould 
that occurs along with a yeast in Japanese koji, the grains 
of which are used by the Japanese in making a strong rice- 
wine. Aspergillus oryzae has a strong diastatic action, and 
furnishes taka diastase, a trade product. 
But another mould or group of moulds, the Mucors, have 
found more favour with European distillers. The most 
important species is Mucor (or Amylomyces) Rouxii, which 
produces practically a straight fermentation from starch to 
alcohol, the saccharification and fermentation proceeding 
simultaneously. _ The process was first used in Europe at 
Lille, in France, and the method consisted in sterilising a 
mash of brewer’s settlings by heating under a pressure of 
two atmospheres. This was followed by cooling and in- 
fecting with the Mucor. After 20 hours. when the mycelia 
had penetrated uniformly throughout the mass, a few cubic 
centimetres of yeast were added, and the fermentation 
allowed to proceed. When the process was finished, 97-5 
