28 LABORATORY MANUAL OF MICROBIOLOGY 



10 per cent sodium hydroxide (NaOH) solution and 10.0 cubic 

 centimeters of a 20 per cent sodiuni sulphite (Na2S03) solu- 

 tion. Now dilute this agar medium with an equal amount of 

 a water suspension of the bacteria. Pour deep plates. 



MEDIA FOR SULPHUR-OXIDIZING BACTERIA 

 Medium 65 



Thiosulphate Solution^ 



Sodium thiosulphate (Na2S203-5H20) 5.0 gm. 



Ammonium chloride (NH4CI) 0.1 gm. 



Sodium bicarbonate (NaHCOs) 1.0 gm. 



Disodium phosphate (Na2HP04-2H20) . 2 gm. 



Magnesium chloride (MgCl2-6H20) 0.1 gm. 



Tap water 1,000.0 cc. 



1 Beijerinck, M. W., Centr. Bakt, II Abt., 11: 593-599, 1904. 



Sterilize the thiosulphate and acid carbonate separately in a 

 small amount of water and when cool add to the solution of the 

 other salts. A trace of ferrous sulphate (sterile solution) should 

 also be added after sterilization. 



Medium 66 

 Thiosulphate-nitrate Solution- 



Sodium thiosulphate (Na2S203-5H20) 2.0 gm. 



Potassium nitrate (KNO3) 10 gm. 



Ammonium chloride (NH4CI) 0.1 gm. 



Sodium bicarbonate (NaHCOs) 1.0 gm. 



Magnesium chloride (MgCl2-6H20) 0.1 gm. 



Disodium phosphate (Na2HP04-2H20) . 2 gm. 



Distilled water 1,000.0 cc. 



2TRAUTWEIN, K., Centr. Bakt. II Abt., 53: 513-548, 1921. 



Medium 67 



Thiosulphate-agar3 



Sodium thiosulphate (Na2S203-5H20) 5.0 gm. 



Dipotassium phosphate (K2HPO4) 0.1 gm. 



Sodium bicarbonate (NaHCOs) . 2 gm. 



Ammonium chloride (NH4CI) 0. 1 gm. 



Agar 20.0 gm. 



Tap water 1,000.0 cc. 



3 Beijerinck, M. W., Centr. Bakt., II Abt., 11: 593-599, 1904. 



