144 



LABORATORY MANUAL OF MICROBIOLOGY 



Nitrogen, determination of, 65 

 fixation in soil, 119 



fixing capacity of soil 



Winogradsky's method, 119 

 fixation by cultures of 



Azotobacter, 116 

 bacteria, media for, 32 

 Nodule bacteria, isolation of, 106 

 and nitrogen content of plants, 



113 

 in agar, 109 

 Normal sodium hydroxide, 55 



sulphuric acid, 54 

 Nutrient agar, 8 

 broth, 8 

 gelatin, 8 

 Nutrition of bacteria, 1 

 Nutrose agar, 9 



Oxalic acid, standard, 55 

 Oxidation of ammonia, 23 

 sulphur, 131 



Paraffin agar, 41 

 Pasteur, 1 

 Pea extract, 34 

 Pentosans, 70 

 Peptone malt agar, 15 



mannitol solution, 12 



sucrose, 35 

 Phenoldisulphonic acid, 60 

 Phenolphthalein, 52 

 Physiological groups, 104 

 Plant material, analysis of, 76 

 Potassium nitrate, thiosulphate solu- 

 tion, 26 

 Potato culture media or potato 

 slants, 39 



glucose agar, 14 

 Preparation of H ion indicators, 53 

 Preservation of stock cultures, 45 

 Preserving plates, 45 



plate cultures, 46 

 Pressure and temperature, 7 

 Protein decomposition, 128 



Protozoa, 94 



media for, 19 



number in soil, 98 

 Pyrogallic acid for absorbing oxygen, 

 46 



R 



Raisin extract, 17 

 Raulin's solution, 12 

 Reaction, 3 

 Reagents, 52 

 Reducing sugars, 72 

 Reduction of sulphates, 26 

 Rock phosphate, 131 

 Root, effect on number of bacteria, 

 102 

 nodule bacteria, isolation, 107 

 structure of. 111 

 Rose bengal, 96 



S 



Safranin, 48 



Schweitzer's reagent, 69 



Season, effect on number, 102 



Sectioning nodules. 111 



Seed sterihzation, 82 



Selective media, 1 



Shaffer and Hartman modified, 72 



Silica gel, general properties, 5 



preparation of, 6 



Souleyre, 35 



use of, 116 

 SiUcic acid gel for nitrite forming 



bacteria, 24 

 Size of organisms in soil, 94 

 Sodium albuminate agar, 9 



asparaginate, glycerol agar, 19 



caseinate agar, 9 



citrate (Koser), 43 

 Soil extract agar, 10 



gelatin, 10 



stock solution, 10 



population, 92 



samples, how taken, 97 

 Sorenson's phosphate (Na2HP04.- 



2H2O), 40 

 Souleyre, silica gel, 35 



