564 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



Use: Differentiation of colon typhoid 

 group. Author reported that typhoid 

 colonies were red and transparent; colon 

 colonies bluish black. 



Reference: Klimmer (1923 p. 216). 



1801. Massini's Triple Dye Lactose Agar 



Constituents : 



1. Nutrient agar (3.0%) 1000.0 cc. 



2. Lactose 30.0 g. 



3. Egg chrome yellow 2 G 1.0 g. 



4. Helvetia blue 0.65 g. 



Preparation : 



(1) Prepare nutrient 3.0% agar. 



(2) Add 30.0 g. lactose, 1.0 g. egg chrome 

 yellow 2 G. and 0.65 g. helvetia blue 

 to 1000.0 cc. of (1). 



Sterilization: Sterilize in the Arnold on 

 each of three consecutive days for 15 

 minutes. 



Use: Detection of typhoid and dysentery. 

 The medium was turned blue by B. coli 

 and other acid forming organisms while 

 the typhoid-dysentery group gave a 

 yellow color. 



Reference: Massini (1918 p. 887) taken 

 from (1918 p. 204). 



1802. Lange's Starch Agar 



Constituents : 



1. Nutrient agar 1000.0 cc. 



2. Starch (rice) (5.0%) 50.0 g. 



Preparation : 



(1) Add 40.0 cc. of a 10.0%, soda solution 

 to 1 liter of agar neutral to litmus. 



(2) Prepare a 5.0% rice starch paste by 

 boiling rice starch in water. 



(3) Mix 6 parts sterile alkaline agar with 

 one part sterile rice starch paste. 



(4) Pour into Petri dishes. 

 Sterilization: Method of sterilization of 



agar not given. Sterilize (2) in the 

 autoclave. 



Use: Diagnosis of cholera. Author re- 

 ported that cholera vibrio showed char- 

 acteristic growth after from 14 to 20 

 hours. Also used to determine the 

 production of diastase by bacteria. 



Variants : 



(a) Tanner added 2.0% paste of potato 

 starch to melted and cooled nutrient 

 agar. 



(b) Allen added 2.0% water soluble starch 



to nutrient agar and sterilized the 

 medium in the autoclave. 

 References: Lange (1916 p. 153), Tanner 

 (1919 p. 60), Allen (1918 p. 15). 



1803. Hoffmann's Nitrate Starch Agar 



Constituents : 



1. Nutrient agar 1000.0 cc 



2. Starch 5.0 g. 



3. KNO3 (0.1%) 1.0 g. 



Preparation : 



(1) Prepare 1000.0 cc. nutrient agar. 



(2) Add 0.5%o starch and 0.1% KNO3 to 

 (1). 



Sterilization: Not specified. 



Use: Differential count of bacteria in soil — 

 nitrate reduction. Treat the seeded 

 plates with a dilute solution of KI in 

 dilute HCl. Author reported that colo- 

 nies reducing nitrate to nitrite had a blue 

 halo around them following this treat- 

 ment. 



Reference: Hoffmann (1912 p. 386). 



1804. Hoffmann's Nitrate Starch Agar 



Same as medium 1803 but using KNOj 

 instead of KNO3. The author reported 

 that colonies reducing nitrite produced a 

 clear halo around the colony when a dilute 

 KI solution in dilute HCl was added. If 

 a yellowish halo was produced around a 

 colony when a dilute solution of Nessler's 

 reagent be added, ammonia was formed. 



1805. Khouvine's Cellulose Agar 



Constituents : 



1. Nutrient agar. 



2. Cellulose. 

 Preparation : 



(1) Add very finely divided Berzelius 

 filter paper or precipitated cellulose 

 to nutrient agar. 

 Sterilization: Not specified. 

 Use: Isolation and enrichment of B. 



cellulose dissolvens. 

 Variants: The author prepared the agar 

 as indicated: 



(1) Place a layer of sterile agar in a sterile 

 Petri dish. 



(2) Add a sheet of sterile filter paper. 



(3) Cover with a layer of melted agar con- 

 taining the organisms. 



Reference: Khouvine (1923 pp. 714, 715). 



