416 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



The reaction was determined by the color standards of Medalia (1920), (1922). 

 * This solution suggested by Skinner and Reid (1921). 



(Sat. 



2.0 cc. 

 15.0 g. 



4. Brom Cresol Purple 

 Solution) 



5. Agar. 



Preparation : 



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



(2) Adjust to pH = 7.0 by the addition of 

 normal NaOH (6.0 cc). 



(3) Dissolve 1.0% of any desired carbo- 

 hydrate, alcohol, etc., in (2). 



(4) Add 2.0 cc. saturated aqueous solu- 

 tion of brom cresol purple to (3). 



(5) Tube. 



Sterilization: Method not given. 



Use: To study fermentation of carbohy- 

 drates, alcohols, etc. A yellow colora- 

 tion indicates the production of acid. 



Added nutrients: The committee recom- 

 mended addition of 1.0% of any desired 

 carbohydrate, alcohol, etc. 



Reference: Committee S. A. B. (1922 

 p. 522). 



1422. Beijerinck's Sodium Ammonium 

 Phosphate Agar 



Constituents: 



1. Distilled water 1000.0 cc. 



2. Agar 



3. NH4NaHP04 (0.2 to 



0.5%) 2.0 to 5.0 g. 



4. KC1(0.05%) 0.5 g. 



5. CaCOs 

 Preparation: 



(1) Prepare a solution of agar in dis- 

 tilled water. Exact concentration 

 not specified. 



(2) Filter and allow to solidify in flasks 

 in thick layers. 



