CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



305 



Preparation : 



(1) Dissolve 2 in 1. 



(2) Boil gelatin in 1.0% HCl, H2SO4, or 

 HNO3 for 6 hours. 



(3) Add 2.0% of (2) to (1). 

 Sterilization: Not specified. 



Use: Acid production by colon-typhoid 



group. 

 Reference: Capaldi and Proskauer (1894 



p. 464). 



989. Robinson and Rettger's Hydrolyzed 

 Casein Solution 



Constituents: 



1. Water 1000.0 cc. 



2. Casein 50.0 g. 



Preparation : 



(1) Boil 50.0 g. of casein with 10.0% HCl 

 under a reflux condenser until the 

 solution no longer responds to the 

 Biuret test. 



(2) Evaporate on the water bath until 

 nearly all the HCl is removed. 



(3) Neutralize the remaining acid with 

 NaOH. This solution is of dark 

 brown color and is known as "Ca- 

 sein C." 



(4) Dissolve 50.0 g. of (3) in 1000.0 cc. of 

 water. 



(5) Heat on water bath for 20 minutes. 



(6) Adjust the reaction neutral to litmus. 



(7) Distribute in 20.0 cc. lots in 150.0 cc. 

 Erlenmeyer flasks. 



(8) After sterilization add 0.1% sterile 

 glucose to one half of the flasks. 



Sterilization: Sterilize at 12 to 14 pounds 



pressure for 15 minutes. 

 Use: Cultivation of B. diphtheriae and 



to.xin production. Authors reported that 



the cultures were nearly non toxic. 

 Variants: The authors prepared a similar 



medium as follows: 



(1) Heat 100.0 g. casein with 400.0 cc. 

 concentrated HCl for a few hours on 

 water bath under a reflux condenser. 



(2) If charring occurs, dilute with 

 150.0 cc. water and heat over free 

 flame for 8 hours. 



(3) Filter off humus residue. 



(4) Filtrate is biuret free and is evapo- 

 rated on water bath with frequent 

 renewal of water. 



(5) Decolorize (method not given). 



(6) Neutralize with NaOH 



(7) Mix 100.0 cc. (6) with 1000.0 cc. water. 



(8) Method of sterilization not given. 

 This medium is inferior to opsine as 

 a general culture medium. 



Reference: Robinson and Rettger (1917 

 p. 364), (1918 p. 219). 



990. Cannon's Hydrolyzed Casein Solution 



Constituents : 



1. Distilled water 1000.0 cc. 



2. Asparagin 5.0 g. 



3. Ammonium lactate 5.0 g. 



4. KH2PO4 2.0 g. 



5. MgS04 0.2 g. 



6. Casein 10.0 g. 



Preparation : 



(1) Hydrolyze 10.0 g. of casein with 

 200.0 cc. of 10.0% H2SO4. 



(2) Keep on a water bath for 24 hours 

 (temperature not given). 



(3) Neutralize by the addition of a satu- 

 rated barium hydroxide solution and 

 filter. 



(4) Evaporate the solution until the 

 amino acids crystallize. 



(5) Dissolve 2, 3, 4 and 5 in 1000.0 cc. of 

 distilled water. 



(6) Add the crystals of (4) to one half 

 of (5). 



Sterilization: Method not given. 



Use: Rapid detection of indol production. 



Variant: Tanner employed all the amino 



acid crystals in step (6) and not only 



one-half. 

 References: Cannon (1916 p. 535), Tanner 



(1919 p. 63). 



991. Berthelot's Hydrolyzed Casein Solution 



Constituents : 



1. Water 1000.0 cc. 



2. Casein 15.0 g. 



Preparation : 



(1) Hydrolyze casein to amino acids by 

 acid (Method not given). 



(2) Dissolve 15.0 g. of the amino acids 

 obtained from the hydrolysis in 

 1000.0 cc. water. 



(3) Exactly neutralize with soda (Indi- 

 cator not specified). 



Sterilization: Sterilize with ether (Method 



not given). 

 Use: To.xin production hy Proteus vulgaris. 

 Reference: Berthelot (1914 p. 916). 



