34 A MANUAL OF THE ASPERGILLI 



In his detailed study of the A. niger group, Biourge's pupil, Mosseray 

 (1934a), gives his simplified Raulin's solution as follows: 



Water, distilled 1,000 ml. 



Sucrose 50 grams 



Tartaric acid 1 0.40 gram 



Magnesium carbonate 1 0.250 gram 



Ammonium nitrate 2 0.250 gram 



Potassium carbonate 2 0.40 gram 



Ammonium phosphate (NH 4 ) 2 HP0 4 1 0.40 gram 



Ammonium sulphate 1 0.20 gram 



Iron sulphate 1 (cryst.) 0.05 gram 



Zinc sulphate 1 (cryst.) 0.05 gram 



Agar-agar 1 20.00 grams 



Sterilize 120° C. for 20 minutes. 



Steinberg's Solution 



Steinberg in the course of many years' investigation of a single strain of 

 Aspergillus niger (NRRL No. 334: Thorn No. 4247) developed a basic for- 

 mula for testing other phases of the nutrition of his mold. It is called the 

 "dibasic optimum" solution and carries mannitol instead of sucrose, sodium 

 nitrite instead of ammonium nitrate, with the addition of sufficient sulphu- 

 ric acid to obtain any desired reaction. Interpolations into this solution 

 offer many possibilities. 



Steinberg's "dibasic optimum" (Thorn and Steinberg, 1939) 



Water (distilled in Pyrex still) 1,000.0 grams 



d-Mannitol 50.0 grams 



i^aNO-: 2.0 grams 



K 2 HP0 4 0.35 gram 



MgS0 4 -7H 2 0.25 gram 



FeS0 4 -7H 2 0.001 gram 



ZnS0 4 -7H 2 0.00088 gram 



CuS0 4 -5H 2 0.00020 gram 



MnS0 4 -4H 2 0.00012 gram 



NaMo0 4 -2H 2 0.00005 gram 



H 2 S0 4 to pH 4. 



A number of so-called natural substrata, including malt extract and hay 

 infusion agars, are very useful in the study of the Aspergilli. A great ma- 

 jority of species sporulate more freely upon malt extract than upon Czapek's 

 solution agar (fig. 9), and for this reason it is very useful where large quan- 

 tities of spores are desired. This medium is, however, less diagnostic than 

 Czapek's solution. 



1 Merck reagents. 



2 Kahlbaum reagents. 



