246 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



(12) Heat until the precipitate appears 

 flaky. 



(13) Filter thru moistened filter paper. 



(14) Tube. 



(15) Sterilize for 20 minutes in a steam 

 sterilizer on 3 consecutive days or 

 in the autoclave at 120° for 20 

 minutes. 



(c) Roux and Rochaix (1911) did not 

 specify the type of peptone used. 



(d) Day and Baker (1912-13) specified 

 Lemco meat extract and Witte's pep- 

 tone. They adjusted the reaction to 

 +1 and cultivated an organism caus- 

 ing ropiness in beer. 



(e) Lohnis (1913) used Witte's peptone 

 and adjusted the reaction alkaline 

 to litmus. 



(f) Rideal and Walker (1913) used 20.0 g. 

 Liebig's meat extract, 20.0 g. Witte's 

 peptone and 10.0 g. NaCl. The me- 

 dium was used for the growth of B. 

 typhosus in the Rideal-Walker test 

 of disinfectants. 



(1) Dissolve the constituents in water 

 by boiling for 30 minutes. 



(2) Filter. 



(3) Neutralize to phenolphthalein. 



(4) Add 15.0 cc. of N/1 HCl. This 

 gives a +1.5 reaction. 



(5) Make up to 1 liter. 



(6) Filter. 



(7) Sterilize (method not given) in 

 500.0 cc. lots. 



(8) Sterilize again on the next day. 



(9) Tube in 5.0 cc. quantities into 

 sterile test tubes. 



(10) Plug with sterile cotton. 



(11) Place in the steam sterilizer for 

 about 30 minutes. 



(g) Brussoff (1916) used 5.0 g. of Merck's 

 iron peptone and 2.5 g. NaCl. The 

 medium was used for the cultivation 

 of Ferribacterium duplex. A slight 

 yellow membrane was formed after 

 5 or 10 days incubation. 



(h) Berman and Rettger (1916) studied 

 erepsin production by members of 

 the colon-typhoid group using 2.5 g. 

 Liebig's meat extract and did not 

 specify the type of peptone (10.0 g.) 

 used, 5.0 g. NaCl was also used, 

 (i) Roddy (1917) used 2.0 g. Liebig's 

 beef extract, 5.0 g. NaCl, and 10.0 g. 



Witte's peptone. The medium was 

 prepared as follows : 



(1) Make a paste of the peptone. 



(2) Dissolve (1) in 1. 



(3) Add 2 and 3 to (2). 



(4) Boil and stir for 30 minutes. 



(5) Make up the loss due to evapora- 

 tion by the addition of water. 



(6) Bring to the boiling point. 



(7) Adjust the reaction as desired. 



(8) Filter when hot and again when 

 cool. 



(9) Sterilize in the autoclave. 



(j) Brussoff (1918) cultivated sludge 

 forms on a medium containing 5.0 g. 

 NaCl, 10.0 g. Witte's peptone, and 

 10.0 g. Liebig's meat extract in a 

 liter of tap water rich in potassium. 



(k) Foster and Randall (1921) studied the 

 changes in pH values of a medium 

 due to autoclaving and standing. 

 They used 5.0 g. NaCl, 10.0 g. Parke- 

 Davis & Co. peptone, 3.0 g. of Liebig's 

 beef extract, or 50.0 g. of Bacto beef 

 in a liter of distilled water. 



(1) Harvey used 3.0 to 5.0 g. of Lemco 

 meat extract and prepared the me- 

 dium as follows: 



(1) Add the whites of 2 eggs to 

 1000.0 cc. water. 



(2) Add to the mixture by degrees to 

 make a suspension; Lemco 3 to 

 5.0 g., peptone 10.0 g., sodium 

 chloride 5.0 g. 



(3) Steam or boil 45 minutes. 



(4) Filter while hot thru well-wetted, 

 thick filter paper or thru 2 layers 

 of absorbent cotton wool. 



(5) Bring the volume up to 1000.0 cc. 

 by the addition of water. 



(6) Estimate and adjust to a definite 

 pH value or faintly alkaline to 

 litmus or 1.0% acid to phenol- 

 phthalein. 



(7) Sterilize in streaming steam or in 

 the autoclave. 



(m) Pitfield (1922) used 3.0 g. Liebig's 

 beef extract, 10.0 g. Witte's peptone 

 and 5.0 g. of NaCl per liter. The 

 medium was prepared as follows: 



(1) Dissolve the constituents in 

 1000.0 cc. of water. 



(2) Weigh the saucepan and contents 

 and heat to 60°C. 



