108 SOIL BACTERIOLOGY 



Medium 38 

 Inorganic Solution for Nitrate Reduction 



Sodium thiosulphite (Na 2 S 2 O 3 + 5H 2 O) 5.0 gm. 



Potassium nitrate (KNO 3 ) 5.0 gm. 



Sodium bicarbonate (NaHCO 3 ) i.o gm. 



Dibasic potassium phosphate (K2HPO 4 ) 0.2 gm. 



Magnesium chlorid (MgCl 2 + 6H 2 O) o.i gm. 



Calcium chlorid (CaCl 2 + 6H 2 O) trace 



Ferric chlorid (FeCl 3 + 6H 2 O) trace 



Distilled water , 1000.0 c.c. 



Lieske, R., Ber. d. deutsch. bot Gesell., Bd. 30, 1912. 



NITROGEN ASSIMILATING ORGANISMS 



A. Free Nitrogen-fixing Bacteria (Aerobic) 



Medium 39 



Mannit Solution 



Mannit (C 6 H 8 (OH) 6 ) 15.0 gm. 



Magnesium sulphate (MgSO4 + yH 2 O) 0.2 gm. 



Monobasic potassium phosphate (KH 2 PO 4 ) 0.2 gm. 



Sodium chlorid (Nad) 0.2 gm. 



Calcium sulphate (CaSO 4 + 2H 2 O) o.i gm. 



Calcium carbonate (CaCO 3 ) 5.0 gm. 



Distilled water. 1000.0 c.c. 



Dissolve the phosphate separately in a little water and make 

 the solution neutral to phenolphthalein with N/i NaOH; 

 then add to the other ingredients. For a solid medium 

 add 15 grams of agar to each liter. 



Ashby, S. F., Jour. Agr. Sci., vol. 2, p. 38, 1907. 



