Page:The yeasts (1920).djvu/14

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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 Fermentation 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 Delbrück'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 111

f. Antiseptics 111