SYNTHETIC MEDIA 
Beijerinck’s Medium for Nitrate Reduction (after Fred). 
Dibasic potassium phosphate, KgHPQ,...... 0.5 gm. 
Potassium nitrate, KNO3............ ...... 10.0 gms. 
Ethyl alcohol, CoHs0OH.................... 5.0 e.c. 
Tap water.........0. 0.0 ccc cece cece eens 1000 c.e. 
Winogradsky’s Medium for Nitrite Formation (from Ferd., 1916). 
Ammonium sulphate, (NHL\2eSO4............ 1.0 gm. 
Dibasic potassium phosphate, (KeHPO,)..... 1.0 gm. 
Magnesium sulphate, MgSOz-7HeO......... 0.5 gm. 
Sodium chloride, NaCl...........0.0..0..... 2.0 gms. 
Ferrous sulphate, FeSO4:7HeO.............. 0.4 gm. 
Magnesium carbonate, MgCOs in excess... .. 5.0 gm. 
Distilled water.............. 0000... c cece 1000 c.e. 
Giltay and Aberson’s (1891) Solution. For Denitrifying Bacteria. 
Distilled water..... 0.0.0.0... 0... cece eee 1000 c.c. 
Potassium nitrate, KNOs................0.. 2 gms. 
Magnesium sulphate, MgSO4............... 2 gms. 
Citric acid... cece cee eee 5 gms. 
Dipotassium hydrogen phosphate, KeHPO... . 2 gms. 
Calcium chloride, CaCle...........0.00000.. 0.2 om. 
Sodium carbonate, NagCO3................. 4.25 gms. 
Asparagin, CoH: (NH2)/ CON Hs 1.00 gm 
EN COOH ° 
67 
This medium should be placed in fermentation tubes before steril- 
ization. To prevent any decomposition, the potassium nitrate and 
asparagin should be dissolved together. The other salts should be 
dissolved in another portion of water and the whole brought up to a 
liter. 
Omelianski’s and Winogradski’s Medium. 
Ammonium sulphate, (NH)SO............... 1 gm. 
Potassium bi-phosphate, KHePO4............. 1 gm. 
Magnesium sulphate, MgSO4-7H2O.......... 0.5 gm. 
Sodium chloride, NaCl.............. 02.0000 2.0 gms. 
Ferrous sulphate, FeSOQ4-7H20............... 0.4 gm. 
Basic magnesium carbonate, 4MgCO3-Mg(OH)e2 Excess 
Distilled water... .0....0-ce cece cere ree eeees 1000 c.c. 
