334 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



but slightly turbid. Washing 5 

 times is usually sufficient. 



(3) After pouring off the last water add 

 18 liters of water to the remaining 

 washed yeast cells. 



(4) Boil in the autoclave or steamer as 

 in the preparation of meat bouillon. 



(5) Allow to stand for a suitable length 

 of time and remove the liquid from 

 the sediment or filter thru filter 

 paper. 



(6) Adjust the filtrate or supernatant 

 fluid to a slight alkaline reaction 

 using litmus as an indicator. 



(7) Sterilization not specified. 



(d) Besson prepared the medium as 

 follows: 



(1) Boil 100.0 g. of beer yeast in 

 1000.0 cc. of water. 



(2) Filter thru paper. 



(3) Distribute as desired. 



(4) The reaction is slightly acid, but 

 may be made slightly alkaline if 

 desired. 



(5) Sterilize at 115°C. 



(e) Dopter and Sacquepee used a me- 

 dium prepared in the following 

 manner: 



(1) Dialyse yeast in 6 times their 

 weight of water. (Time not given.) 



(2) Boil, stirring constantly. 



(3) Filter. 



(4) Distribute. 



(5) Sterilize. 



(f) Harvey added 75.0 g. pressed yeast 

 to 1000.0 cc. of water. Further prep- 

 aration not given. 



(g) Harvey prepared a medium as 

 follows : 



(1) Add 100.0 g. yeast to 1000.0 cc. 

 water. 



(2) Boil 10 minutes. 



(3) Filter thru well-wetted, thick filter 

 paper. 



(4) Adjust the reaction. 



(5) Distribute into flasks or test tubes. 



(6) Sterilize in the autoclave or 

 steamer. 



(h) Harvey prepared a similar medium 

 as follows: 



(1) Prepare: Baker's yeast 1; water 5. 



(2) Boil 20 minutes, with vigorous 

 stirring. 



(3) Place in a tall glass vessel 24 hours. 



(4) Decant the supernatant fluid. 



(5) Make neutral to litmus. 



(i) Klimmer used a medium prepared as 

 follows: 



(1) Dilute 10 liters of Brewers yeast or 

 beer yeast with 20 liters of water. 



(2) Allow to stand for 0.5 to 11 hours, 

 remove the water and add fresh. 

 Repeat the process until the wash 

 water is slightly turbid. 



(3) Make up the volume of the yeast 

 to 18 liters. 



(4) Boil in the autoclave or steamer. 



(5) Allow to settle. 



(6) Decant or filter. 



(7) Use the filtrate as meat peptone and 

 peptone or nutrose. 



(8) The solution may be evaporated to 

 dryness. 



(9) The filtrate may be used by the 

 addition of 0.5% NaCl and making 

 slightly alkaline. 



(j) Cunningham prepared a medium as 

 follows: 



(1) Place 1000.0 g. of fresh pressed 

 yeast in a double walled pot and 

 mix thoroly with 1000.0 cc. of water. 



(2) Steam for one hour. 



(3) Filter thru paper. 



(4) Tube in 5.0 cc. quantities. 



(5) Sterilize by intermittent steaming. 

 References: Thoinot and Masselin (1902 



p. 29), Henneberg (1903 p. 8), Heinemann 

 (1905 p. 130), Gassner (1916-17 p. 311), 

 Besson (1920 p. 34), Dopter and Sacquepee 

 (1921 p. 121), Harvey (1921-22 p. 120), 

 Klimmer (1923 p. 170), Cunningham 

 (1924 p. 103). 



1149. Stoklasa's Arabinose Azotobacter 

 Solution 



Constituents : 



1. Distilled water 1000.0 cc. 



2. d-arabinose 1-0 g. 



3. MgCl2 0.5 g. 



4. Iron sulphate 0.1 g. 



5. Azotobacter culture. 

 Preparation : 



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



(2) Distribute in 250.0 cc. lots in Fern- 

 bach fermentation tubes. 



(3) Adjustment of reaction not specified 



(4) Add an azotobacter membrane from 

 mannitol culture to each flask. 



