380 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



make up to 0.04% brom cresol purple 

 by the addition of water. 

 (2) Add sufficient of (1) to milk to give a 

 distinct color. 

 Sterilization: Method not specified. 

 Use: General culture medium. Kahn cul- 

 tivated spore forming anaerobes. 

 Variants: Kahn cultivated spore forming 

 anaerobes in a medium prepared as 

 follows : 



(1) Add 40.0 cc. of brom cresol purple 

 indicator solution to 1 liter partially 

 skimmed milk (strength of indicator 

 solution not specified). 



(2) Tube in 10.0 cc. lots. 



(3) Autoclave at 15 pounds for 20 

 minutes. 



(4) The tubes are sealed with a vaseline 

 cap. 



References: Harvey (1921-22, p. 88), Kahn 

 (1922, p. 175). 



1302. Harvey's China Blue Rosolic Acid 



Milk Solution 



Constituents : 



1. Water 100.0 cc. 



2. Milk, skimmed 300.0 cc. 



3. China blue (1.0% solution) 



4. Rosolic acid (0.5% solution) 

 Preparation : 



(1) Mix 1 part creamed milk with 3 parts 

 water. 



(2) Mix equal parts of a 1.0% watery 

 china blue solution and a 0.5% al- 

 coholic rosolic acid solution. 



(3) To each 100.0 cc. of (1) add 2.5 cc. of 

 (2). 



(4) Raise to boiling point and boil 5 

 minutes. 



(5) Adjust the reaction by bringing the 

 color, with the addition of alkali, 

 to a pale grey. 



(6) Distribute into test tubes containing 

 gas tubes which should project above 

 the surface. 



Sterilization: Sterilize in the autoclave. 

 Use: General culture medium. 

 Reference: Harvey (1921-22 p. 95). 



1303. Bacto Purple Milk, (Dehydrated) 



Constituents: 



1. Distilled water 1000.0 cc. 



2. Purple milk Bacto 105.0 g. 



Preparation : 



(1) Dissolve 105.0 g. of Bacto Purple 

 Milk (dehydrated) in 1000.0 cc. of 

 distilled water. 



Sterilization: Sterilize in the usual manner. 

 The dye will stand heating to a total 

 not over 70 minutes. 



Use: General culture medium. Acid pro- 

 ducers change the color to yellow, alkali 

 producers to purple. 



Reference: Digestive Ferments Co. (1925 

 p. 13). 



1304. Bacto Whey Broth (Dehydrated) 



Constituents: 



1. Water 1000.0 cc. 



2. Whey, Broth, Bacto 30.0 g. 



Preparation : 



(1) Dissolve 30.0 g. of Bacto Whey Broth 

 (dehydrated) in 1000.0 cc. of distilled 

 water. 



(2) If sterilized at 15 pounds pressure for 

 20 minutes pH = 6.5 ±. 



Sterilization: Sterilize in the usual manner. 

 Use: Cultivation of Lactobacillus bul- 



garicus. 

 Reference: Digestive Ferments Co. (1925 



P-14). 



1305. Stutzer and Hartleb's Whey Solution 



Constituents: 



1. Whey. 

 Preparation : 



(1) Separate the cream from milk. 



(2) Heat to 40°C. and add a little rennet. 



(3) After the casein has coagulated heat 

 to 75°C. and filter. 



(4) Neutralize by the addition of soda 

 (indicator not specified). 



Sterilization: Not specified. 



Use: Cultivation of the causitive agent of 

 the foot and mouth disease. Other in- 

 vestigators employed the medium as a 

 general culture medium. 



Variants : 



(a) The author added Na2C03 to obtain 

 an alkaline reaction, or lactic acid to 

 obtain an acid reaction. 



(b) Percival prepared the medium in the 

 following manner: 



(1) Add 10.0 cc. of distilled water 

 containing 8 to 10 drops of com- 

 mercial rennet extract to 1000.0 cc. 

 of skimmed or separated milk. 



