CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



417 



(3) Pour distilled water over the solidified 

 agar and allow to stand for several 

 days. Pour off this water and add 

 fresh distilled water from time to 

 time. This process removes all solu- 

 ble material from the agar. 



(4) Add 0.2 to 0.5% NH4XaHP04 and 

 0.05% KCl to the agar, also pre- 

 cipitated CaCOs (amount not given). 



(5) Boil. (This serves to sterilize.) 



(6) Distribute into sterile dishes. 

 Sterilization: Sterilization is accomplished 



in step (5) above. 



Use: To show nitrite formation by Amoeba 

 nitrophil. Author reported that the 

 colonies producing nitrites formed a 

 clear ring around the colonies due to the 

 action of nitrites on CaCOa. Killer culti- 

 vated protozoa and other soil forms on a 

 similar medium. 



Variants: Killer specified the use of 0.2% 

 NH,NaHP04 • 4H2O and omitted the 

 CaCOs. 



References: Beijerinck (1896 p. 258), Killer 

 (1913 p. 523). 



1423. Stutzer's Ammonium Magnesium 

 Phosphate Agar 



Constituents: 



1. Water ^, 1000.0 cc. 



2. Agar '. 10.0 g. 



3. K2HPO4 1.0 g. 



4. NaCl 5.0 g. 



5. FeS04 0.5 g. 



6. Ammonium magnesium 

 phosphate 20.0 g. 



7. MgCOa 20.0 g. 



Preparation: 



(1) Dissolve 2, 3, 4 and 5 in 1. 



(2) Mix equal amounts of 6 and 7 in a 

 mortar. 



(3) Add about a half teaspoon of (2) to 

 test tubes. 



(4) Add 10.0 to 15.0 cc. of melted (1) to 

 each tube. 



Sterilization: Method not specified. 

 Use: To study nitrification by soil forms. 

 Reference: Stutzer (1901 p. 173). 



1424. Corper's Basal Ammonium Phosphate 

 Agar 



Constituents : 



1. Water, tap 1000.0 cc. 



2. Salt (sea salt) 5.0 g. 



3. Ammonium phosphate 3.0 g. 



4. Agar 30.0 g. 



Preparation : 



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



(2) Neutralize to litmus by the addition 

 of NaOH. 



(3) Add one of the added nutrients listed 

 below. 



Sterilization: Sterilize in the autoclave. 

 Use: Cultivation of tubercle bacilli. 

 Added nutrients: The author added one of 

 the following: 



(a) Glycerol 5.0% 



(b) Glycerol 5.0% 



Beef extract (Liebig's) 0.3% 



(c) Glycerol 5.0% 



Peptone (Witte) 1.0% 



(d) Glycerol 5.0% 



Beef extract (Liebig's) 0.3% 



Peptone (Witte) 1.0% 



(e) Glycerol 5.0% 



Add 1.0% defibrinated rabbit blood 

 at 43°C. and inspissate on each of 

 3 successive days for 90 minutes. 



(f) Same as (e) but using laked blood. 



(g) Same as (e) but using cow's milk, 

 (h) Same as (e) but using 10.0% casein. 



(i) Same as (e) but using whole egg. 



(j) Same as (e) but using egg white. 



(k) Glycerol 5.0% 



Add 1.0% sodium nucleinate, pre- 

 pared by neutralizing yeast nu- 

 cleic acid in warm water by means 

 of Na2C03 solution. Inspissate as 

 in (e). 



(1) Glycerol 5.0% 



Add a suspension of yeast nuclein 

 sufficient to make a 1.0% suspen- 

 sion. Inspissate as in (e). 



(m) Glycerol 5.0% 



Add 1.0% of a mush of testes from 

 rabbits. Inspissate as in (e). 



(n) Same as (m) but use liver from rab- 

 bits instead of testes. 



(o) Same as (m) but use brain from rab- 

 bits instead of testes. 

 Reference: Corper (1919 p. 463). 



SUBGROUP II-B. SECTION 3 



Basal or complete media containing agar 

 with inorganic constituents. Nitrogen sup- 

 plied as nitrites or nitrates. 

 Ai. Nitrogen supplied as nitrites. 



