38 A MANUAL OF THE ASPERGILLI 



Sporulation medium for A.flavus (Moyer, Personal communication) 



Glucose (commercial) 165.0 grams 



Bacto-Peptone 1 .0 gram 



MgSCV7H 2 0.050 gram 



KH 2 P0 4 0.060 gram 



KNOj 0.500 gram 



Fe (as tartrate) 0.040 gram 



Agar 0.25 gram 



Distilled water to make 1 liter 



The above solution can be used as a solid medium by increasing the agar 

 concentration to 30.0 gm. per liter. (The small amount of agar included in 

 the basic formula is added solely for the purpose of increasing viscosity.) 

 Incubation should be at 22° to 24° C. This factor is critical for maximum 

 spore production with the kojic acid producing strain, NRRL No. 484 

 (Thorn No. 3538), for which the medium was developed. This medium can 

 also be successfully employed for spore production in A . niger by incubating 

 cultures at 30° C. 



Abundant sporulation of many strains and species can be secured by cul- 

 tivation upon bread, whole cereal grains, or various types of milled products 

 of the same. Bread, if used, should not contain proprionates or other mold 

 inhibitors. The material to be inoculated should be moist but in no sense 

 wet, and special precautions must be taken to insure that the grain or bread 

 is properly sterilized before being used. The use of grain as a substratum 

 for molds dates back to prehistoric time in the fermentation industries of 

 the Orient where rice was, and still is, commonly used to produce the 

 "koji," or inoculum, used in the alcoholic and soya fermentation industries 

 of that area. In its classic usage, the molds cultivated were mostly mem- 

 bers of the A. flavus-oryzae group, but experience has shown that this 

 general type of medium can be used to advantage to secure heavy sporula- 

 tion of many other forms. From such material, series of surface fermenta- 

 tion flasks or other vessels can be uniformly inoculated by various means 

 involving aspiration of spores, or the direct transfer of heavily spore-laden 

 particles. Spore suspensions can be prepared and used for seeding sub- 

 merged cultures 



TYPES OF CULTURE 



Cultures for grouping and identification of the Aspergilli should be 

 grown in petri dishes. At the same time an adequate number of slanted 

 tubes should be inoculated and held in reserve as an uncontaminated stock 

 culture. Colonies so situated in the petri dish that they can be viewed 

 directly under low magnifications with the compound microscope are neces- 

 sary to supply a clear picture of the structure and course of development 

 of mycelium and fruiting parts. Such colonies can be obtained by several 



