186 AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



the sprouting of the barley grain in which there has devel- 

 oped the maximum amount of diastase together with the 

 minimum amount of transformation of starch. The sprouts 

 are then broken off and the grain dried. This is termed the 

 malt and is usually ground before use. The malt contains 

 not only enough amylase or diastase to transform the starch 

 present but much greater quantities as well. When ground 

 malt is mixed with warm water the diastase goes into solu- 

 tion and rapidly transforms the starch present into the 

 sugar maltose. If malt is added to any solution of boiled 

 starch, there will be rapid transformation of practically all 

 the starch present into maltose. For example, corn meal, 

 rice meal, or boiled potatoes, when mixed with malt, soon 

 dissolve and become sweet, due to the development of the 

 malt sugar. Malt is the most common of the agencies 

 employed for the saccharification of starch, preliminary to 

 alcoholic fermentation, or when such transformation is 

 required for other purposes. 



In the commercial manufacture of alcohol for industrial 

 purposes, cheaper methods for saccharifying starch have 

 been discovered. Certain species of molds, particularly 

 certain members of the genera Aspergillus and Rhizopus, 

 are known to secrete large quantities of the enzyme amylase. 

 These molds may be grown in the laboratory upon suitable 

 sugar media, and the spores collected in large quantities. 

 The material to be saccharified is usually boiled to soften it. 

 Most frequently starch from rice, potatoes, or corn, is 

 employed for this purpose. When sufficiently cooled, the 

 spores of the Aspergillus or Rhizopus are introduced and 

 mixed through thoroughly. Frequently air is bubbled 

 through the mass to facilitate rapid growth of the mold 

 mycelium. This soon penetrates to all portions of the mass 

 and at once begins to excrete the enzyme amylase. Within 

 a few hours or days, the whole mass of starch has been 

 liquefied and transformed into sugar. Yeast can then be 



