808 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



least 100°C. for 20 minutes on 3 suc- 

 cessive days. 



(14) Dissolve 2.0 g. (NH4)2S04, 1.0 g. 

 K2HPO4, 2.0 g. NaCl, 0.5 g. MgS04 

 0.4 g. FeS04 and HCl in 1000.0 cc. 

 distilled water and sterilize (method 

 not given). 



(15) Inoculate. 



(16) To each 10.0 cc. of medium add 0.5 

 cc. of (14) under aseptic conditions. 



(17) Slant or pour into plates. 

 References: Omelianski (1899 p. 541), Per- 



cival (1920 p. 146, 148), Harvey (1921-22 

 p. 106). 



2473. Beijerinck's Ammonium Sodium 

 Phosphate Silicate Jelly 

 Constituents: 



1. Water. 



2. Waterglass. 



3. HCl. 



4. CaCOs. 



5. NH4NaHP04 



6. KCl. 

 Preparation : 



(1) Titrate commercial waterglass 

 exactly with half normal HCl. 



(2) Prepare a CaCOs solution. 



(3) Determine the necessary amounts of 

 0.5 N HCl, Waterglass and CaCOj 

 to mi.x together so that a suitable 

 jelly is obtained. 



(4) Measure these solutions into plates 

 when ready for use and mix. Solidi- 

 fication will depend upon the ratio in 

 which the reagents are mixed. 



(5) Extract the soluble salts from the 

 plates by pouring boiled distilled 

 water over the plates. 



(6) Add the desired amount of a solution 

 containing NH4NaHP04 and KCl 

 with other desired salts. 



Sterilization: Not specified. 



Use : To study nitrite formation by Amoeba 



nitrophila. 

 Reference: Beijerinck (1896 p. 259). 



2474. Doryland's Basal Glucose Silicate 

 Jelly 

 Constituents: 



1. Distilled water 500 cc 



2. K2Si03 (C.P.) 24 g " 



3. NasSiOs (C.P.) 8.4 g. 



4. HCl dilute 



5MgS04 0.5 g 



6- CaO 001 



7-Fe2(S04)3 ooig 



8-MnS04 o.Olg 



9. H2SO4 



10. H3PO4 



11. Glucose 

 Preparation : 



(1) Dissolve 8.4 g. NajSiOs and 24.0 g. 

 K2Si03 in 500.0 cc. distilled water. 



(2) Dilute HCl to such a concentration 

 so that 1.0 cc. of (1) does not quite 

 neutralize 1.0 cc. of HCl. (Phenol- 

 phthalein as indicator.) 



(3) Add the following salts to the HCl- 



MgS04 0.5 g.' 



S^O o.Olg. 



Fe2(S04)3 o.Olg 



MnS04 O.Olg.' 



One of the added nutrients. 



(4) Standardize (3) so that 1.0 cc. of (3) 

 is equivalent to 1.0 cc. of (1). 

 Methyl orange as indicator. 



(5) Standardize solution of H2SO4 in 

 same manner as HCl omitting the 

 salts. 



(6) Standardize H3PO4 in same way as 

 HCl omitting salts and using phenol- 

 phthalein. 



(7) Mix acids in following proportions- 



HCl 153.5 CO. 



H2SO4 77.0 CC. 



H^PO^ 116.0 cc. 



(8) 1.0 cc. of (7) should neutralize 1.0 cc. 

 of (1) using phenolphthalein as 

 indicator. 



(9) Draw (1) and (7) into plugged 

 burettes and allow to stand several 

 hours to sterilize. 



(10) Draw 5.0 cc. of (7) and 5.0 cc. of (1) 

 into a sterile Petri dish, add enough 

 sterile aqueous glucose solution tc 

 have 10.0 g. per liter of medium 

 Rotate. Hardens in 5 minutes. 

 Sterilization : See step (9) above. 

 Use: Solid synthetic medium. 

 Added nutrients: The author added one of 

 the following: 

 KNO3 

 K6Fe2(CN)i, 



(NH4)2S04. 



Reference: Doryland (1916 p. 148). 



