x CONTENTS 



PAGE 



CHAPTER III 

 PHYSIOLOGY, NUTRITION, RESPIRATION, AND ALCOHOLIC FERMENTATION 



1. Chemical Composition of Yeasts 53 



2. General Considerations of the Enzymes in Yeasts 58 



3. Proteolytic Enzymes in Yeasts 59 



a. Proteases 59 



b. Nucleases or Enzymes of Nucleo-Proteins 60 



4. Lipase 61 



5. Carbohydrate Enzymes 61 



a. Polysaccharides 62 



b. Trisaccharides 63 



c. Disaccharides 63 



d. Glucosides : 65 



6. Oxidizing and Reducing Enzymes 66 



7. Toxins 67 



8. Nutrition of Yeasts 68 



a. Mineral Elements 68 



b. Nitrogenous Substances 69 , 



c. Hydrocarbon Compounds 75 



9. Respiration 80 



10. General Characteristics of Alcoholic Fermentation 81 



a. Conditions Necessary for Its Production 82 



b. General Occurrence of Alcoholic Fermentation 84 



c. Comparison of Intramolecular Respiration with Alcoholic Fermen- 



tation 84 



d. Differences in the Fermenting Function in Different Yeasts 85 



11. Fermentable Sugars 86 



12. Formula of Alcoholic Fermentation and Secondary Products 88 



13. Characteristics and Properties of Buchner's Zymase 89 



14. Mode of Action of Zymase 94 



15. General Theories of Alcoholic Fermentation 99 



a. Pasteur's Theory 99 



b. Wortmann and Delbriick's 100 



c. Theory which Makes Fermentation a Phase of Respiration 101 



16. Autophagy or Autolysis of Yeasts 104 



CHAPTER IV 

 PHYSIOLOGY (continued) 



1. Habitat of Yeasts 106 



2. Duration of Life of Yeasts. 107 



3. Action of Physical Agents on Yeasts 108 



a. Temperature 108 



b. Light 109 



c. Moisture 109 



d. Metals and Salts 109 



e. Pressure Ill 



/. Antiseptics Ill 



