304 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



(4) Allow to autolyze for one week at 



37.5°C. 



(5) Pass thru a Berkefeld filter. 



(6) Adjustment of reaction not given. 



(7) Add sterile (method of sterilization 

 not given) physiological salt solution 

 to (5). Amount of each not given. 



They used the medium to study the 

 influence of vitamines on bacterial 

 growth. 

 Reference: Abt and Blanc (1921 p. 452), 

 Robertson and Davis (1923 p. 154). 



985. Robertson and Davis' Yeast Autolysate 



Solution 



Constituents : 



1. Sterile distilled water to. . . 1000.0 cc. 



2. Asparagin (Merck) 3-4 g 



3. CaCU 0.1 g 



4. Dextrose 20.0 g 



5. MgS04 0.2 g 



6. K2HPO4 1.0 g 



7. NaCl 5.0 g 



8. Yeast. 

 Preparation : 



(1) Dissolve 2, 3, 4, 5, 6 and 7 in 1 by 

 boiling 3 minutes. 



(2) Restore original volume with sterile 

 distilled water. 



(3) Adjust reaction to pH = 7.4. 



(4) Tube. 



(5) Grow yeast on dextrose agar slants. 



(6) Suspend in sterile distilled water, 

 throw down in centrifuge and wash in 

 sterile distilled water 3 times. 



(7) Kill yeast by heating 70°C. for 10 

 minutes. (This suspension contained 

 about 500,000 per cc.) 



(8) Allow to autolyze for 1 week at 

 37.5°C. 



Sterilization: Sterilize (4) ty autoclaving 

 at 20 pounds pressure for 30 minutes. 

 Filter (8) thru a Berkefeld to sterilize. 



Use: To study influence of vitamins on 



!_ bacterial growth. Authors reported a 



^ luxuriant growth of yeast. 



Reference: Robertson and Davis (1923 

 p. 154). 



986. Davis and Ferry's Hydrolyzed Gelatin 



Solution 



Constituents : 



1. Distilled water 1000.0 cc. 



2. Hydrolyzed gelatin (syrup). 20.0 g. 



3. Tryptophane 0.4 g. 



4. Tyrosine 1 -5 g. 



5. Cystin 0.4 g. 



6. NaCl 5.0 g. 



7. K2HPO4 3.0 g. 



8. MgS04 0.5 g. 



Preparation : 



(1) Hydrolyze gelatin with 25.0% H2SO4 

 for 24 hours on sand bath. (Tem- 

 perature not given.) 



(2) Add Ba(OH) 2 until alkaline and filter. 



(3) Neutralize exactly the Ba(0H)2 with 

 10.0% H2SO4. Filter. 



(4) Test filtrate for presence of free Ba 

 and SO4 ions. 



(5) Concentrate to a thick syrup in a 

 vacuum. 



(6) Dilute to 2.0% solid material with 

 distilled water 



(7) To each liter of (6) add 3, 4, 5, 6, 7 



and 8. 



(8) Adjust reaction to pH 8.0-8.2 with 

 N/10 NaOH. See med. 474. 



Sterilization: Heat for 20 minutes at 115°C. 



Use: Cultivation of Bad. diphtheriae for 

 toxin production. Authors reported that 

 this medium was superior to most syn- 

 thetic amino acid media. Amino acids 

 used were chemically pure. 



Reference: Davis and Ferry (1919 p. 231). 



987. Capaldi and Proskauer's Hydrolyzed 



Gelatin Solution 

 Constituents: 



1. Water 1000.0 cc. 



2. NaCl (0.02%) 0.2 g. 



3. MgS04 (0.01%) 0.1 g. 



4. K2HPO4 (0.2%) 2.0 g. 



5. Gelatin (2.0%) 20.0 g. 



Preparation : 



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



(2) Boil gelatin for 6 hours in 1.0% HCl, 

 H2SO4 or HNO3. ■ 



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

 Sterilization: Not specified. 



Use: General culture medium. Author re- 

 ported that typhoid bacteria showed no 

 growth in this medium. 



Reference: Capaldi and Proskauer (1896 

 p. 460). 



988. Capaldi and Proskauer's Mannitol 

 Hydrolyzed Gelatin Solution 

 Constituents : 



1. Water 1000.0 cc. 



2. Mannitol (0.1%) 1.0 g. 



3. Gelatin (2.0%) 20.0 g. 



