183 



Nitrogen sources 



Nitrification: nitritation, influence of or- 

 ganic substances, III. 113, 238; IV. 

 261; V. 181; VI. 71. 



Winogradsk y's theory of chemo- 

 synthetic carbon dioxide assimilation, 

 III. 238; IV. 180, 205, 206, 379; V. 191. 



Nitrite: assimilation by microorganisms, 



111. 7, 8, 11, 22, 31, 183; IV. 339; 



V. 16, 273; VI. 61. 



- formation, demonstration, III. 18, 19, 

 20, 117, 190; IV. 195; V. 184, 185. 



- oxidation as an energy source in che- 

 mosynthesis, IV. 379; V. 191. 



Nitrite bacteria (nitrous bacteria) : III. 

 1 13, 189; IV. 240; V. 181-184; VI. 71. 



- cultivation, III. 190; VI. 71. 



- description, IV. 261, 265*; VI. 71. 

 Nitrogen compounds: influence on Azo- 

 tobacter enrichment cultures, IV. 110- 



112, 149, 377, 383; V. 122; VI. 4, 7, 21. 



- influence on Azotobacter pure cultures, 

 IV. 117, 119, 122, 139, 140. 



- influence on Bacillus radicicola, II. 

 164, 183, 184, 323, 324; III. 50; IV. 

 115, 119; V. 269; VI. 61. 



- influence on Cyanophyceae, IV. 106, 

 107, 126, 127, 239; V. 135. 



- influence on root nodules, II. 323. 



- influence on Spirillum lipoferum, VI. 

 6, 21, 24. 



- microbiochemical quantitative de- 

 termination, III. 7-10. 



nutrition of unicellular green Algae, 

 II. 296, 297, 300, 308, 313, 316; III. 

 22, 24; IV. 106-108, 126, 239; V. 134, 

 135. 



- present in air, VI. 61, 69, 70. 



- quantity present in tapwater and soil, 

 IV. 106, 125, 256. 



Nitrogen cycle in the soil and in the sea, 

 IV. 174, 178, 258, 260, 262; V. 232. 



Nitrogen fixation: by Aerobacter in 

 symbiosis with Azotobactev, IV. 139, 

 140, 146. 



- by Azotobacter, first discovery, IV. 175. 



- by Azotobacter, experiments with pure 

 cultures, IV. 166-168, 298-301, 304; 



VI. 4. 



- by Azotobacter in combination with 

 other bacteria, IV. Ill, 118, 139-145, 

 149, 150, 159, 164, 165-170, 175, 176, 

 256*. 257, 258, 262, 300-302, 377; V. 

 232; VI. 3. 



- by Azotobacter, influence of acidity, 

 IV. 143, 257. 



Nitrogen fixation: by Azotobacter, influ- 

 ence of calcium, IV. Ill, 122, 143, 

 298-300, 302; VI. 3. 



- by Azotobacter, influence of oxygen, 



IV. 302. 



- by Azotobacter, influence of the salts of 

 organic acids, IV. 110, 112, 113, 143, 

 161, 165, 175,298-300,302; V. 231; VI. 

 4, 21-23. 



- by Azotobacter, quantity, IV. 154 

 159, 164, 300-303. VI. 3, 4, 26. 



- by Bacillus mesentericus, IV. 167, 169, 

 178. 



- by Bacillus radicicola, experiments, 



II. 183-185, 323, 324; IV. 259; V. 

 264-271; VI. 61-70. 



- by Bacillus radicicola in symbiosis 

 with Papilionaceae, IV. 256, 258, 259; 



V. 267, 268. 



- by Bacillus radiobacter, IV. 144, 163, 

 170, 179, 257. 



- by bacteria, IV. 105-127, 139, 179, 

 180, 205, 256*, 257, 262, 298-304; 379; 

 V. 135, 229, 231, 232, 264-271 ; VI. 3-8, 

 21-27. 



- by bacteria, annual quantity in the 

 soil, V. 232; VI. 26. 



- by Cyanophyceae, IV. 108, 127, 183, 

 239; V. 135, 229.' 



- by Cyanophyceae, annual quantity in 

 the soil, V. 229. 



- by Granulobacter in symbiosis with 

 other bacteria, IV. 152, 153, 161, 175, 

 178, 179; V. 231, 232; VI. 3. 



- by Granulobacter in pure culture, IV. 



III, 139, 149-153, 161, 164, 167, 173, 

 178, 179; V. 267. 



- by Helobacter, V. 267. 



- by mixtures of pure cultures, IV. 145, 

 167-170-175. 



- by Spirillum lipoferum, VI. 21-24-27. 



- determination of the quantity, IV. 

 154, 155. VI. 66-68. 



- first assimilation product, IV. 140, 

 178, 260; V. 232. 



- with cellulose as a carbon source, IV. 

 256*, 257, 262; V. 232. 



Nitrogen fixing power of the soil, VI. 25, 26. 

 Nitrogen loss of the soil, IV. 18. 

 Nitrogen sources for microorganisms, 



II. 201, 256, 296-298, 316, 337, 338; 



III. 7-11, 18-22, 30-32, 61, 133, 183, 

 184, 276, 277; IV. 28, 73, 81, 91, 118, 

 200, 226, 279, 297, 353-355; V. 5, 8, 9, 

 16-18, 202, 273. 



