460 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



(7) Sterilize by heating 20 minutes on 

 3 successive days. 



(h) Levine gave the following medium as 

 Bile Salt (Rebipel) Agar (After 

 Savage): Sodium taurocholate 5 

 grams, Witte's peptone 20 grams and 

 distilled water 1 liter, are boiled up 

 together, 20 grams of agar are added 

 and dissolved in the solution in the 

 autoclave in the ordinary way. The 

 medium is cleared with white of egg 

 and filtered. After filtration, 10 

 grams of lactose and 5 cc. of recently 

 prepared 1 per cent neutral red solu- 

 tion are added. The medium is then 

 tubed and sterilized for 15 minutes on 

 three successive days. 



(i) Harvey gave the following method 

 of preparation : 



(1) Dissolve 20.0 g. peptone, 5.0 g. 

 sodium taurocholate in 1000.0 cc. 



tap water and make faintly alkaline 

 to litmus. 



(2) Steam 45 minutes. 



(3) Add 15.0 g. powdered agar, making 

 it into a paste or suspension, 

 before addition, with a little of the 

 taurocholate peptone solution. 



(4) Steam gently 2^ hours to bring the 

 agar thoroughly into solution. 



(5) Bring the volume up to 1000.0 cc. 

 by the addition of water. 



(6) Cool to 60°C., clarify by the addi- 

 tion of egg and filter. 



(7) Dissolve 10.0 g. lactose (or other 

 sugar if desired) in 15.0 cc. sterile 

 water and steam 15 minutes. 



(8) Add the lactose solution to the 

 hot, clear, nutrient agar. 



(9) Add 5.0 cc. freshly prepared sterile 

 1 per cent neutral red by means 

 of a sterile pipette. 



(10) Distribute the resulting agar, 

 which is deep red, into flasks or 

 test tubes. 



(11) Steam 25 minutes. 



(j) Cunningham prepared the medium as 

 follows: 



(1) Steam 5.0 g. sodium taurocholate 

 and 20.0 g. peptone in 1000.0 cc. 

 water for one hour. 



(2) Filter. 



(3) Add 1.5% agar and steam for one 

 hour. 



(4) Filter while hot thru cotton wool. 



(5) Add 1.0% lactose dissolved in a 

 little water and 1.0% Andrades 

 indicator. 



(6) Sterilize intermittently. 

 References: MacConkey (1900 p. 20), (1901 



p. 740), Frost (1903 p. 342), MacConkey 

 (1905 pp. 334, 336), (1908 p. 325), Abel 

 (1912 p. 227), Ball (1919 p. 81), Tanner 

 (1919 p. 49), Percival (1920 p. 307), 

 Harvey (1921-22 p. 89), Klimmer (1923 

 p. 214), Levine (1921 p. 116), Cunningham 

 (1924 p. 98). 



1595. Harrison and VanderLeck's Aesculin 

 Bile Salt Agar 



Constituents: 



1. Water 1000.0 cc. 



2. Peptone (Witte (1.0 or 



2.0%) 10.0 or 20.0 g. 



3. Sodium taurocholate 

 (Commercial) (0.5%) 5.0 g. 



4. Aesculin (0.1%) 1.0 g. 



5. Iron citrate (0.05%) . 0.5 g. 



6. Agar 15.0 g. 



Preparation : 



(1) Dissolve the agar in part of 1. 



(2) Add 2, 3 and 4 to the rest of 1. 



(3) Mix (1) and (2). 



(4) Boil and filter (may be clarified with 

 egg white). 



(5) Tube. 



Sterilization: Sterilize by steaming on 3 

 successive days or autoclaving at 15 

 pounds for 15 minutes. 



Use: Presumptive test for B. coli in water 

 analysis. Author reported that B. coli 

 colonies were black, typhoid colonies 

 produced no blackening. 



Variants : 



(a) The authors used 0.25% commercial 

 bile salt, 1.0% Witte's peptone and 

 0.1% iron citrate instead of amounts 

 used above. 



(b) Levine gave Eyre's method of prep- 

 aration as follows: 



(1) Measure out 400.0 cc. distilled water 

 into a tared 2 liter flask. 



(2) Weigh out 15 grams agar, 10 grams 

 peptone, 5 grams sodium taurocholate 

 and make into a thick paste with 150.0 

 cc. distilled water. 



(3) Add this paste to the distilled water 

 in the flask. 



