CULTURE METHODS 



29 



3. Soil extract medium Lohnis.^ 



Prepare a soil extract by heating 1 kg. of soil with 1 liter of 

 water ia an autoclave for half an hour at 15 lb. pressure, or heat 

 1 kg. of soil with 2 hters of water over an open flame for two 

 hours. Filter the hot solution through paper and use as directed 

 in the f ollowiug formula : 



Soil extract . . . . 

 Potassium phosphate 

 Mannite or dextrose . 

 Agar 



1000 cc. 

 • 5g. 

 . 10 g. 

 . 15 g. 



Exercise 51. Preparation of Winogradsky and Omelianski's Solution for 

 Cultivating Nitrite-Forming Organisms 



Ammonium sulphate 

 Potassium Iriphosphate 

 Magnesium sulphate . . 

 Sodium chloride . . . 

 Ferrous sulphate . . . 

 Basic magnesium carbonate 

 Distilled water .... 



1.0 g. 

 1.0 g. 

 0.5 g. 

 2.0 g. 

 0.4 g. 

 Excess 

 1000.0 cc. 



Exercise 52. Preparation of Winogradsky and Omelianski's Solution for 

 Cultivating Nitrate-Forming Organisms 



Potassium biphosphate . 

 Sodium chloride . . . 

 Ferrous sulphate . . . 

 Magnesium sulphate 

 Fused sodium carbonate 

 Sodium nitrite . . . 

 Distilled water . . . 



. 0.5 g. 



. 0.5 g. 



■ 0.4 g. 



. 0.3 g. 



. 1.0 g. 



. 1.0 g. 

 1000.0 cc. 



Exercise 53. Preparation of Naegeli's Solution 



This solution has been found to be well suited for the culture 

 of yeast and of many other fungi. 



Calcium chloride . 0.1 g. 



Magnesium sulphate 0.2 g. 



Dipotassium phosphate 1-0 g. 



Ammonium tartrate 10.0 g. 



Distilled water 1000.0 cc. 



I Centralbl. i. Bakt., 2te Abt., 14 : 590. 1905. 



