CONTENTS. 



CHAPTER I. FOOD OF MICROORGANISMS 8 



The composition of the cell Moisture, cell wall, cell contents.-Amount of food re- 

 Organic food materials,-Non-nitrogenous food compounds, nitrogenous 

 food compounds.-Mineral food.-Oxygen.-Additional remarks on microbial food - 

 Physiologic groups, synthetic media. 



CHAPTER II. PRODUCTS OF METABOLISM 



The chemical equations of fermentations. Physiological variations. Products' from 

 nitrogen-free compounds, Cellulose, starch, sugar, alcohols, organic acids, fats. Pro- 

 ducts from nitrogenous compounds Protein bodies, ptomains, urea, uric acid, hip- 

 puric acid. Products from mineral compounds, -Oxidations, reductions. -Unknown 

 products of physiological significance, Pigments, aromatic substances, enzymes and 

 -Rotation of elements in nature.-Carbon cycle, nitrogen cycle, sulphur cycle 

 phosphorus cycle.-Physical products of metabolism.-Production of heat produc- 

 tion of light. 



CHAPTER III. MECHANISM OF METABOLISM x , 



General theory of metabolism, Fermentation (intra- and extra-cellular), katabo- 

 lism and anabolism. Intra- and extra-cellular fermentation.-Decomposition of in- 

 soluble food, properties of enzymes, mechanism of fermentation.-Classincation of 

 enzymes.-Hydrolytic enzymes (enzymes of carbohydrates, enzymes of fats, enzymes 

 of proteins), coagulating enzymes, zymases, oxidizing enzymes, reducing enzymes 

 Additional remarks on the relation of cells and enzymes.-Theory of katabolism - 

 Theory of anabolism Interaction of anabolism and intra-cellular fermentation, 

 reversibility of enzymic action. 



DIVISION II. PHYSICAL INFLUENCES. 

 CHAPTER I. MOISTURE . 



Osmotic pressure.-Plasmolysis.-Salt and sugar solutions, colloidal solu'tions. -Des- 

 iccation. 



CHAPTER II. INFLUENCE OF TEMPERATURE , 



Optimum temperature. Minimum temperature. Maximum temperature. Bio- 

 logical significance of the cardinal points of temperature. -End-point of fermentation. 

 Freezing. Thermal death-point. Resistance of spores. 



CHAPTER III. INFLUENCE OF LIGHT AND OTHER RAYS ... I ( >2 



Phototaxis. X-rays. Radium rays. 



CHAPTER IV. INFLUENCE OF ELECTRICITY l66 



CHAPTER V. IHFLUENCE OF PHYSICAL STRUCTURE OF THE MEDIUM .... . 167 



CHAPTER VI. INFLUENCE OF MECHANICAL EFFECTS .168 



Pressure. Gravity. Agitation. 



DIVISION III. CHEMICAL INFLUENCES. 



CHAPTER I. STIMULATION OF GROWTH 17I 



Chemotropism and chemotaxis. 



CHAPTER II. INHIBITION OF GROWTH .173 



Poisons, germicides, disinfectants, antiseptics, preservatives. Mode of action. Fac- 

 tors influencing disinfection. Classification of disinfectants. 



DIVISION IV. MUTUAL INFLUENCES. 

 SYMBIOSIS. METABIOSIS. ANTIBIOSIS .!8i 



