FERMENTATION 319 



ments. When seeds are soaked in water, the diastase 

 and proteose enzymes are extracted and if precipitated 

 with alcohol and recovered, they appear as a light gray 

 powder. An organized ferment is a low form of plant, 

 while a soluble ferment is a chemical compound. 



439. Aerobic and Anaerobic Ferments. Ferments 

 which require oxygen for their existence are aerobic 

 while those which are capable of working in the absence 

 of oxygen are anaerobic. The aerobic ferments produce 

 carbon dioxid, water, ammonia and hydrogen sulfid as 

 final products, while the anaerobic ferments usually pro- 

 duce intermediate products as organic acids. 



440. Conditions Necessary for Fermentation. The 



conditions necessary for fermentation are : ( i ) Moisture, 

 (2) favorable temperature, (3) a ferment body, and (4) 

 a fermentable substance. Moisture is necessary in order 

 that the chemical changes may take place. During 

 fermentation water frequently enters into the chemical 

 reaction, as in hydration changes, and is also neces- 

 sary as a medium of exchange for the chemical products 

 during the reaction. The most favorable temperatures 

 for fermentation are between 15 and 60 C. Below 

 zero and above the boiling-point of water, ferments are 

 inactive. Some ferments require a different temperature 

 for activity than others. A ferment body is always neces- 

 sary in order to start the fermentation change, and in the 

 absence of a ferment either organized or unorganized, no 

 fermentation can take place. A fermentable substance, 

 with the right kind of ferment to act upon it, is also req- 



