IMPORTANCE OF FERMENTATION IN FARM LIFE 33 
is the immediate cause of blood clotting; cyiase is an important 
enzyme, acting upon several parts of a plant cell and causing the 
cell structure to disintegrate; pectase causes the formation of 
vegetables jellies from materials in vegetable cells; urase brings 
about the ammoniacal fermentation of urea. All of the actions 
above mentioned are the result of chemical decomposition in the 
fermenting body, generally accompanied by the absorption of 
water. There is another class of enzymes, called oxidases, which 
cause the fermenting body to absorb oxygen. Among these are, 
daccase, an enzyme concerned in the formation of lacquer varnish 
from sap; tyrosinase, producing colors in fungi; and oenoxydase, an 
enzyme that causes certain diseases in wine. This list could be 
largely increased by adding other less important enzymes. 
The simple enumeration of these lists is sufficient to emphasize 
their variety, and only a brief examination is needed to show their 
intimate relation to farm processes. Nearly all of those enumer- 
ated have a more or less important relation to farm life, and not a 
few farm products are quite dependent upon them, for example: 
vinegar-making, due to the action of both yeasts and bacteria, and 
cheese making, due to the enzyme, rennet, and likewise to bacteria. 
When to this list we add the many serious animal and plant dis- 
eases caused by germ life, with which the farmer is waging con- 
stant warfare, it becomes evident that agriculture and bacteriology 
must hereafter be closely combined. 
Recognizing the great variety of these allied phenomena, it 
becomes a little uncertain to what the term fermentation should 
be applied It originally referred to the alcoholic fermentation, 
but later it was applied to the changes due to enzymes, and en- 
zymes as well as yeasts were said tobeferments. Frequently ithas 
been applied to any type of sugar fermentation brought about by 
yeasts or bacteria, by which gas is produced; and when bacteri- 
ologists use the term they usually refer simply to this change in 
sugars. A term with so varied a meaning is of little value, and 
to-day there is a tendency to give upzits use, except in a popular 
“sense to cover such a general list of phenomena. 
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