CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



707 



malachite green solution in sterile 



water. Do not boil. 

 (10) Pour in Petri dishes. 

 Sterilization: Not specified. 

 Use: General culture medium. 

 Reference: Tanner (1919 p. 52). 



2189. Noyes' Starch Extract Agar 



Constituents: 



1. Water 1000.0 cc. 



2. Agar (best) 15.0 g. 



3. Extract (Liebig) 5.0 g. 



4. Starch 4.0 g. 



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

 Sterilization: Not specified. 



Use: General culture medium. Primarily 



used to study soil organisms. 

 Reference: Noyes (1916 p. 93). 



2190. Malenkovid's Xylose Extract Agar 



Constituents : 



1. Water 1000.0 cc. 



2. Xylan 20.0 g. 



3. Meat extract, Liebig's 5.0 g. 



Preparation: (1) Dissolve 2 and 3 in 1. 

 Sterilization: Not specified. 



Use: Cultivation of Merulius lacrymans. 

 Reference: Malenkovid (1906 p. 407). 



2191. Hiss' Gelatin Extract Agar 



Constituents: 



1. Water 1000.0 cc. 



2. Beef extract, Liebig's 5.0 g. 



3. NaCl 5.0 g. 



4. Agar 5.0 g. 



5. Gelatin 80.0 g. 



6. Glucose 10.0 g. 



Preparation : 



(1) Dissolve agar in 1000.0 cc. of water 

 to which beef extract and NaCl have 

 been added. 



(2) When agar is completely melted 

 dissolve the gelatin by a few minutes 

 boiling. 



(3) Titrate and adjust to 1.5% normal 

 acid to phenolphthalein. 



(4) Add one or two eggs beaten in 25.0 cc. 

 of water and boil for 45 minutes. 



(5) Filter thru thin filter paper or ab- 

 sorbent cotton. 



(6) Add the glucose after clearing. 



(7) Tube. 



Sterilization: Method of sterilization not 

 given. 



Use: Differentiation of colon-typhoid 

 group. Author reported that on the 

 medium given above B. typhosus gave a 

 uniform clouding. Colon bacilli gave 

 only growth where inoculated. 



Variants : 



(a) Hiss prepared a similar medium using 

 10.0 g. agar instead of 5.0 g., and 

 25.0 g. of gelatin instead of 80.0 g. 

 The reaction is adjusted to 2.0% acid 

 instead of 1.5%. This medium is 

 poured in plates when ready for use. 

 On this medium the author reported 

 that deep B. typhosus colonies under 

 low power were small and generally 

 spherical with rough irregular out- 

 line. By transmitted light they were 

 of a vitreous greenish or yellowish- 

 green color. Showed threaded 

 growth. Deep colon colonies were 

 usually much larger and were spheri- 

 cal or of whetstone form. By trans- 

 mitted light they were darker more 

 opaque and less refractive than 

 typhoid colonies. By reflected light 

 they were pale yellow. Neither of 

 the organisms spread thru the me- 

 dium. The typhoid colonies ap- 

 peared to the naked eye as mere 

 greyish points among the much 

 larger and yellowish colon colonies. 



(b) Hiss gave the following method of 

 preparation of a similar medium. 

 He reported that typhoid colonies 

 were small greenish, irregular and 

 fringed with threads. Colon colonies 

 were larger and did not form threads. 



(1) Boil 15.0 g. agar in 1000.0 cc. 

 distilled water over a free flame for 

 30 to 45 minutes to dissolve. 



(2) Dissolve 15.0 g. gelatin, 5.0 g. 

 Liebig's extract and 5.0 g. NaCl in 

 (1). _ 



(3) Clarify by the addition and coagu- 

 lation of the whites of two eggs. 



(4) Filter thru absorbent cotton. 



(5) Dissolve 10.0 g. glucose in (4). 



(6) The reaction is usually about 1.2% 

 acid to phenolphthalein and no 

 acid or alkali is added. 



(7) Tube in about 10.0 cc. lots. 



(8) Sterilize in the usual manner at 

 100°C. on 3 successive days. 



References: Hiss (1897 pp. 681, 694), 



