il6 SOIL BACTERIOLOGY 



SULPHUR ORGANISMS 



Reduction and Oxidation 



Medium 55 



Solution for Sulphate Reduction 



Dibasic potassium phosphate (K2HPO4) . . 0.5 gm. 



Magnesium sulphate (MgS04 -f 7H2O) i.o gm. 



Ferrous sulphate (FeS04 + 7H2O) trace 



Asparagin (C4H8N2O3 + H2O) i.o gm. 



Sodium lactate (NaCsHsOs) S-ogm. 



Tap-water looo.o c.c. 



Van Delden, Centbl. Bakt. (etc.), Abt. 2, Bd. 11, p. %^, 1904. 



Medium 56 

 Gelatin for Sulphate Reduction 



Gelatin 120,0 to 150.0 gm. 



Dibasic potassium phosphate (K2HPO4) 0.5 gm. 



Magnesium sulphate (MgSO^ + 7H2O) 1.0 gm. 



Iron-ammonium sulphate (FeS04(NH4)2(S04) + 



6H2O) trace 



Asparagin (C4H8N2O3 + H2O) 1.0 gm. 



Sodium lactate (NaCsHsOg) S-o gm. 



Distilled water looo.o c.c. 



Sterilize in the autoclave at 10 pounds' pressure for fifteen 

 minutes. Cool in ice-water. 



Medium 57 

 Solution for Sulphate Reduction 



Dibasic potassium phosphate (K2HPO4) 0,5 gm. 



Sodium lactate (NaCsHeOa) S-o gm. 



Ammonium sulphate ((NH4)2S04) 2.0 gm. 



Ferrous sulphate (FeS04 + 7H2O) trace 



Tap-water looo.o c.c. 



