CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



219 



Sterilize at 15 pounds for 15 minutes 

 after the pressure reaches 15 pounds, 

 provided the total time of exposure 

 to heat is not more than 30 minutes. 

 Otherwise sterilize a 10.0% watery 

 solution of any desired carbohydrate 

 at 100°C. for 1.5 hours, and add to 

 sterile nutrient broth in sufficient 

 quantity to give 0.5% carbohydrate. 

 Tube and sterilize this mixture at 

 100°C. for 30 minutes. It is per- 

 missible to add sufficient sterile 

 carbohydrate solution to each tube 

 of sterile neutral broth by means of 

 a sterile pipette. Incubate these 

 tubes for 24 hours to test sterility. 



(f) Park, Williams and Krumwiede (1924) 

 added 2.0% litmus solution (reagent 

 of highest purity) or 1.0% Kahl- 

 baum's azolitmin to Committee 

 A. P. H. A. (1920) broth. They ad- 

 justed the reaction to neutral to 

 phenolphthalein (pH about 8.0) and 

 sterilized for 15 minutes at 15 pounds 

 pressure after the addition of 0.5% 

 of any desired carbohydrate. The 

 tubes were cooled rapidly. 



(g) Committee A. P. H. A. (1925). Same 

 medium as Committee A. P. H. A. 

 (1920) except that the reaction is 

 adjusted from pH 6.2 to pH 7.0. 



References: Mudge (1917 p. 406), Com- 

 mittee A. P. H. A. (1917 p. 85), Com- 

 mittee S. A. B. (1918 p. 116), Ball (1919 

 p. 77), Tanner (1919 p. 44), Committee 

 A. P. H. A. (1920 p. 95), Levine (1921 

 p. 110), Park, Williams and Krumwiede 

 (1924 p. 131), Committee A. P. H. A. 

 (1925 p. 97). 



755. Percival's Basal Extract Broth 



Constituents: 



1. Water 1000.0 cc. 



2. Meat extract (Lemco) 10.0 g. 



3. Peptone 10.0 g. 



4. Sodium bicarbonate 1-0 g. 



5. Litmus (Kubel-Tiemann) 

 Preparation : 



(1) Dissolve 2, 3, 4 and one of the added 

 nutrients in 1. 



(2) Add sufficient boiled Kubel-Tie- 

 mann's litmus solution to give a violet 

 tinge. 



Sterilization: Method not given. 



Use: To study fermentation of carbo- 

 hydrates, alcohols, etc. 

 Added nutrients and variants: 



(a) The author added 1.0% of one of the 

 following: 



lactose dulcitol 



sucrose adonitol 



glucose 



(b) Harvey prepared the medium 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) Add 1.0% of any desired carbo- 

 hydrate, alcohol, etc. 



(8) Sterilize in the autoclave or flowing 

 steam. 



References: Percival (1920 p. 308), Harvey 

 (1921-22 pp. 68, 108). 



756. Rogers, Clark and Evans' Basal 

 Extract Broth 



Constituents: 



1. Water 1000.0 cc. 



2. Peptone 10.0 g. 



3. Beef extract 4.0 g. 



4. Na2HP04 5.0 g. 



Preparation: (1) Dissolve 2, 3, 4 and 1.0% 



of one of the added nutrients in 1. 

 Sterilization: Not specified. 

 Use: To determine fermentation of carbo- 

 hydrates, alcohols, etc. by bacteria. 

 Added nutrients and variants: 



(a) The authors added 1.0% of one of the 

 following materials to the ba.sic 

 solution: 



glucose inulin 



sucrose mannitol 



lactose glycerol 



raffinose adonitol 



starch dulcitol 



