CULTIVATION AND EXAMINATION 37 



SPORULATION MEDIA 



In addition to the ordinary handling of molds in the laboratory, explora- 

 tion of their biochemical potentialities often necessitates the production of 

 considerable quantities of spores. Whereas some of the media listed above 

 may be employed for this purpose, it is generally advisable to employ 

 so-called "sporulation media." Requirements of different species and 

 strains vary and one frequently has to develop special solutions to meet the 

 needs of particular organisms under study. Such media may be used either 

 as liquid substrata or as solutions solidified with agar. In either case the 

 objective is the same: to secure the maximum production of spores with the 

 production of as little vegetative mycelium as possible. 3 



A number of sporulation media for use with different molds have been 

 developed by Dr. A. J. Mover. Three of these will be cited, while addi- 

 tional formulae may be found in the papers published by members of the 

 Fermentation Division, Northern Regional Research Laboratory. 



Sporulation medium for A. niger {Moyer, Wells, Stubbs, 

 Hcrrick, and May, 1937) 



Glucose 91 .3 grams 



NH 4 N0 3 0.450 gram 



KH 2 P0 4 0.072 gram 



MgS0 4 -7H 2 0.060 gram 



Beer 60.0 ml. 



Distilled water to make 1 liter 



This solution can also be used as a solid medium by the addition of 0.5 

 gm. per liter CaC0 3 and 30.0 gm. per liter agar. The above solution was 

 subsequently modified as follows (Gastrock, Porges, Wells, and Moyer, 

 1938): 



Glucose 50.0 grams 



(NH 4 ) 2 HP0 4 0.560 gram 



KH,P0 4 0.144 gram 



MgS0 4 -7H,0 0.120 gram 



Peptone 0.20 gram 



Beer 45.0 ml. 



Distilled water to make 1 liter 



3 For the surface inoculation of nutrient solutions in small flasks or other con- 

 tainers, dry spores in quantity can be removed from agar surfaces and floated on the 

 liquid surface by means of a 5 mm. loop. To inoculate from a liquid culture, tae 

 usual procedure is to remove a small portion of the heavily sporing mat, transfer 

 this to the solution, and dislodge the spores by vigorous agitation. Spores from 

 either type of culture can be suspended in water and used as inoculum in submerged, 

 or shaken, cultures. The addition of sodium lauryl sulfonate to the suspending water 

 in a concentration of 1 : 10,000 aids greatly in securing uniform spore suspensions. 



