22 PRODUCTS OF BACTERIAL ENERGY 



From the bodies of ground yeast cells a soluble ferment, Zymase, 

 has been expressed, which causes alcoholic fermentation of cane, 

 and grape sugars. This fact proves that fermentation is not neces- 

 sarily a vital process. VThe fermentations of bacterial enzymes 

 may give acids, and also aldehydes, ketones, CO 2 , CO, H, N, NH 3 , 

 marsh gas and H 2 S. The carbohydrate splitting powers are used 

 in determinative bacteriology. VArty^t^ V^AMM"! 



Fermentation and putrefaction are bacterial enzymir processes of 

 indispensable importance to life. Bacteria reduce excrementitious 

 matters to their elements and then others build up these elements 

 into conditions favorable for plants. This process affects the 

 cycle of utility of carbon, sulphur and particularly nitrogen in the 

 air and soil. Some soil bacteria can fix nitrogen from the air for 

 the use of plants. Because of the importance of these processes, 

 cultures of appropriate bacteria may be spread upon exhausted soil. 

 These are chiefly nitrifying bacteria. Manure contains the denitri- 

 fying organisms. Bacterial fermentations produce the flavor of 

 tobacco, opium and butter.. 



Enzyme Production by Bacteria. Ferments of great variety 

 and power are formed by the zymogens, as proteolytic, which dissolve 

 proteids, such as casein; tryptic, gelatine liquefy ing; diastase, which 

 converts starch into sagsutyinvertase, which changes cane sugar into 

 grape sugar; ferments that curdle the casein of milk; and it may well 

 be thaljtlie activity of pathogenic bacteria in the body is due to 

 ferments of some kind. The hemolytic action of the golden staphy- 

 lococcus or the tetanus bacillus is thought, by some, to be of enzymic 

 nature. ^ <H^K/T*w ^*M T^W 



^Organized ferments (bacteria, 1 yeasts) differ from the unorganized 

 (pepsin, diastase) . The latter " exercises solely a hydrolytic action " 

 (Fischer), causing the molecules of insoluble compounds to take up 

 water and to separate into less complex molecules of a different con- 

 stitution, which are soluble in water. The organized ones act differ- 

 ently. Highly complex molecules are split up, and numerous sub- 

 stances of a totally different character are formed with the evolu- 



