DEHYDRATED CULTURE MEDIA 245 



BACTO 



CZAPEK DOX BROTH (B338) 



DEHYDRATED 



Saccharose, Difco 30 g. 



Sodium Nitrate 3 g. 



Dipotassium Phosphate 1 g. 



Magnesium Sulfate 0.5 g. 



Potassium Chloride 0.5 g. 



Ferrous Sulfate 0.01 g. 



Bacto-Czapek Dox Broth is a liquid medium, nearly neutral in reaction, pre- 

 pared from materials of known chemical composition and designed for the culti- 

 vation of fungi and bacteria capable of utilizing inorganic nitrogen. Sodium 

 nitrate is the sole source of nitrogen, and saccharose serves as a source of carbon 

 in this medium. Bacto-Czapek Dox Broth is a modification of the Czapek formula 

 of Doxi prepared according to the directions given by Thom and Raper.^ 



Media prepared with only inorganic sources of nitrogen and chemically de- 

 fined compounds as sources of carbon are useful for a variety of microbiological 

 procedures. They are of principal value in soil microbiology, for the enrichment, 

 cultivation and identification of soil bacteria and fungi, or for mildew resistance 

 tests, as well as for other tests wherein a simple chemically defined medium is de- 

 sired. Czapek Dox Broth will support a moderately vigorous growth of nearly 

 all saprophytic Aspergilli.^ 



To rehydrate the medium, dissolve 35 grams of Bacto-Czapek Dox Broth in 

 1000 ml. distilled water. Distribute in tubes or flasks and sterilize in the autoclave 

 for 15 minutes at 15 pounds pressure (121°C.). Final reaction of the medium 

 will be pH 7.3. 



One pound of Bacto-Czapek Dox Broth will make 13 liters of medium. 



1 U. S. Dept. Ag. Bur. Anim. Ind. Bull., "Thorn and Raper, Manual of the Aspergilli: 



120:70:1910. 39:1945- 



BACTO 



CZAPEK SOLUTION AGAR (B339) 



DEHYDRATED 



Saccharose, Difco 30 g 



Sodium Nitrate 2 g, 



Dipotassium Phosphate 1 g, 



Magnesium Sulfate 0.5 g, 



Potassium Chloride 0.5 g, 



Ferrous Sulfate 0.01 g 



Bacto-Agar 15 g, 



Bacto-Czapek Solution Agar is a solid neutral medium of known chemical 

 composition with nitrate as the only source of nitrogen for the cultivation of 

 saprophytic fungi, soil bacteria and other microorganisms. It is prepared accord- 

 ing to the formula given by Thom and Church.^ This medium is of value in many 

 microbiological procedures such as the cultivation and identification of fungi, 

 growth of soil bacteria, mildew resistance tests and others. Thom and Raper^ 

 state that this medium will produce a moderately vigorous growth of nearly all 

 saprophytic Aspergilli, and yield characteristic mycelia and conidia useful in 

 comparative studies. 



To rehydrate the medium suspend 49 grams of Bacto-Czapek Solution Agar in 

 1000 ml. cold distilled water. Heat to boiling to dissolve the medium completely. 



