24 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



5. NaCl (0.01%) 0.1 g. 



6. FeClj trace 



7. CaCO, 



Reference: Harvey (1921-22 p. 103), Nik- 

 lewski (1910 p. 410). 



68. Christensen's Ammonium Sulphate 

 Solution 



Constituents : 



1. Water 1000.0 cc. 



2. (NH4)2S04 1.6 g. 



3. K0HPO4 2.0 g. 



Preparation : 



(1) Dissolve 2 and 3 in 1. 



(2) Distribute in 50 cc. lots in 500.0 cc. 

 tuberculin flasks. 



(3) Add 1.0 g. of lime to each flask. 

 Sterilization: 20 minutes at 120°C. in auto- 

 clave. 



Use : Inoculate with soil to study nitrifying 



bacteria. 

 Reference : Christensen (1913 p. 418). 



69. Gage's Ammonium Sulphate Solution 



Constituents : 



1. Water 1000.0 cc. 



2. (NH4)2S04 4.0 g. 



3. KH2PO4 2.0 g. 



4. MgS04 1.0 g. 



5. FeS04 0.8 g. 



6. NaCI 4.0 g. 



Preparation : 



(1) Dissolve 2, 3, 4, 5 and 6 in 1. 



(2) Distribute in Erlenraeyer flasks. 

 Sterilization: Method not specified. 



Use: Study of nitrification by soil organ- 

 isms. 

 Reference: Gage (1910 p. 31). 



70. Omeliansky 's Ammonium Sulphate Solu- 



tion (Lohnis-Arnd) 



Constituents : 



1. Distilled water 1000.0 cc. 



2. (NH4)2S04 1.0 g. 



3. K2HPO4 1.0 g. 



4. MgS04 + 7H20 0.5 g. 



5. NaCl 2.0 g. 



6. FeS04 + 7H20 0.4 g. 



7. K2CO, 

 Preparation : 



(1) Dissolve 2, 3, 4, 5 and 6 in 1. 



(2) After sterilization distribute under 

 aseptic precautions, in 50.0 cc. lots in 



300.0 cc. Erienmeyer flasks, each con- 

 taining 0.5 g. pure K2CO3. 



Sterilization: (1) is sterilized for one hour 

 in streaming steam. The flasks contain- 

 ing the K2CO3 are sterilized for 20 minutes 

 under a pressure of 2 atmospheres in the 

 autoclave. 



Use: Inoculate with 5.0 g. of soil to study 

 nitrification. 



Reference: Arnd (1916 p. 561). 



71. Lohnis' Ammonium Sulphate Solution 



Constituents: 



1. Distilled water 1000.0 cc. 



2. (NH4)2S04 1.0 g. 



3. K2HPO4 1.0 g. 



4. MgS04 0.5 g. 



5. NaCl 2.0 g. 



6. FeS04 0.4 g. 



Preparation : 



(1) Dissolve 2, 3, 4, 5 and 6 in 1. 



(2) During incubation at 20 to 25°C. 

 allow some ordinary gas to enter the 

 incubator. 



Sterilization: Not specified. 



Use: To study the assimilation of Ca2 by 



B. oUgocarbophilus. 

 Reference: Lohnis (1913 p. 106). 



72. Stutzer's Ammonium Magnesium 

 Phosphate Solution 



Constituents: 



1. Water 2000.0 cc. 



2. K2HPO4 2.0 g. 



3. NaCi 0.5 g. 



4. Dry ammonium magnesium 

 phosphate 20.0 g. 



5. FeS04 0.5 g. 



6. MgC03 20.0 g. 



Preparation : 



(1) Dissolve 2, 3 and 4 in 1000.0 cc. water. 



(2) Dissolve 5 and 6 in 1000.0 cc. water. 



(3) After sterilization mix (1) and (2) 

 in equal amounts and distribute in 

 sterile flasks by means of sterile 

 pipettes. 



Sterilization: Method not specified. 



Use: Inoculate with a loop of soil suspen- 

 sion. Transfer from flask to flask, using 

 as an enrichment medium. 



Variants: Stutzer used the constituents in 

 the following proportions: 



