Io8 SOIL BACTERIOLOGY 



Medium 38 

 Inorganic Solution for Nitrate Reduction 



Sodium thiosulphite (Na2S203 + SH2O) 5.0 gm. 



Potassium nitrate (KNO3) 5.0 gm. 



Sodium bicarbonate (NaHCOs) i.o gm. 



Dibasic potassium phosphate (K2HPO4) 0,2 gm. 



Magnesium chlorid (MgCl2 + 6H2O) o.i gm. 



Calcium chlorid (CaCl2 + 6H2O) trace 



Ferric chlorid (FeCls + 6H2O) trace 



Distilled water looo.o ex. 



Lieske, R., Ber. d. deutsch. bot GeselL, Bd. 30, 191 2. 



NITROGEN ASSIMILATING ORGANISMS 



A. Free Nitrogen-fixing Bacteria {Aerobic) 



Medium 39 

 Mannit Solution 



Mannit (C6H8(OH)6) 15.0 gm. 



Magnesium sulphate (MgS04 + 7H2O) 0.2 gm. 



Monobasic potassium phosphate (KH2PO4) 0.2 gm. 



Sodium chlorid (NaCl) 0.2 gm. 



Calcium sulphate (CaS04 + 2H2O) o.i gm. 



Calcium carbonate (CaCOs) 5.0 gm. 



Distilled water looo.o 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. 



