748 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



French gelatin in 1000.0 cc. of 

 bouillon. 



(2) Allow to soak for 5 minutes. 



(3) Heat. 



(4) Stir until solution is complete. 



(5) Sterilize in the steamer for 15 min- 

 utes on each of 3 successive days. 



(e) Bezangon prepared the medium as 

 follows: 



(1) Dissolve 100.0 g. of gelatin (126.0 

 to 150.0 g. in summer) in 1000.0 cc. 

 bouillon. 



(2) Coolto50"C. 



(3) Add the beaten white of an egg. 



(4) Adjust the reaction to slightly 

 alkaline. 



(5) Heat for 15 minutes at 110°C. 



(6) Filter while hot. 



(7) Tube. 



(8) Sterilize at 110°C. for 15 minutes. 



(f) Giltner added 3.0% NaCl to nutrient 

 gelatin and adjusted to —2.0%. The 

 medium was used for the cultivation 

 of phosphorescent halophilic or- 

 ganisms. 



(g) Cunningham prepared the medium 

 as follows: 



(1) Add 10.0% Coignet's gelatin to 

 bouillon. 



(2) Steam for 1 hour to dissolve the 

 gelatin. 



(3) Adjust to a slight alkalinity using 

 turmeric paper as an indicator 

 (distinctly brown). 



(4) Steam again for 45 minutes. 



(5) Readjust the reaction if necessary. 



(6) Cool the medium to 50°C. and add 

 1-0% egg albumin mixed to a 

 thin paste in a few cc. of water. 



(7) Steam for 45 minutes. 



(8) Filter hot thru gray filter paper 

 that has had boiling water poured 

 thru it. 



(9) Tube in 8.0 cc. quantities. 



(10) Sterilize intermittently in steam. 

 References: Wurtz (1897 p. 28), Smith 

 (1902 p. 86), Sergent (1906 p. 1015), 

 Lohnis (1913 p. 15), Roddy (1917 p. 43), 

 Worth (1919 p. 604), Bezangon (1920 

 p. 113), Giltner (1921 p. 370, Cunningham 

 (1924 p. 13). 



2309. Heller's Indicator Nutrient Gelatin 

 Constituents : 

 1. Nutrient gelatin. 



2. Neutral red (Sat. Aq. soln. Grubler's 

 or other indicator). 

 Preparation: (1) Add 4 drops of sterile 

 saturated watery solution of Grubler's 

 neutral red to 10.0 cc. of sterile melted 

 gelatin at 40°C. 

 Sterilization: INlethod of sterilization of 

 gelatin or neutral red solution not given. 

 Use: Neutral red test for coli organisms. 

 Author reported that B. coli caused a 

 decolorization and fluorescence of this 

 medium after 6 hours. Other investi- 

 gators used similar media for purposes 

 as indicated. 

 Variants : 



(a) Calandra added 4 drops of a sterile 

 1.0% watery solution of brilliant 

 cresyl blue to 10.0 cc. of sterile nu- 

 trient gelatin. The gelatin was 

 colored bright green. The medium 

 was used to differentiate colon bacilli 

 from typhoid bacilli. He reported 

 that B. coli did not cause decoloriza- 

 tion after 24 hours. Typhoid in con- 

 trast gave a light green layer on the 

 upper surface. After several days, 

 however, the gelatin was completely 

 decolorized if B. coli be present. A 

 thin light green layer remained if 

 typhoid bacilli be present. 



(b) Signorelli added 1.0 cc. of a 1.0% 

 solution of dahlia to each 10.0 cc. of 

 neutral nutrient gelatin. He used 

 the medium to show adsorption of 

 the dye by the cholera vibrio and 

 reported that liquefaction and de- 

 colorization took place at the same 

 time. The bacteria were highly 

 colored. 



(c) Signorelli added 1.0 cc. of a 1.0% 

 solution of erythrosin and 1.0 cc. of 

 a 1.0% solution of safranin to 10.0 cc. 

 of neutral nutrient gelatin. He re- 

 ported that the cholera vibrio ad- 

 sorbed the dye, being highly colored 

 and that the gelatin was liquefied. 



(d) Besson prepared a medium using 

 Noeggerath's indicator solution. 



(1) Prepare saturated watery solution 

 of methylene blue, gentian violet, 

 methyl green, chrysoidine and 

 fuchsin. 



(2) Mi.x 2.0 cc. of methylene blue 

 4.0 cc. gentian violet, 1.0 cc. of 



