GROWTH OF SOME PARASITIC FUNGI IN 
SYNTHETIC CULTURE MEDIA 
H. C. Young and C. W. Bennett ^ 
(Received for publication January 7, 1922) 
In some studies on parasitism being conducted by the writers, it early 
became imperative that considerable attention be given to synthetic 
nutrient solutions for fungi. Evidence points strongly to food as being 
at least one of the dominant factors in the type of growth produced, and in 
the variations obtained. The presence or absence of any of the essential 
inorganic elements may vary the grow^th forms to such an extent that 
structural changes may develop. Striking responses to chemicals have 
been noted, in color changes as shown by Milburn (8) and Bessey (i), by 
generic changes as in the presence or absence of setae in Colletotrichum 
lindemuthianum, and of conidial chains in Alternaria hrassicae and Macro- 
sporium hrassicae, as reported by Stevens (15), and by changes in the 
hydrogen-ion concentration during growth of the organism. The last is 
undoubtedly a factor in parasitism. 
The work of Pasteur (10) on yeasts led to a very extensive investigation 
of the food requirements of fungi. The early investigators dealt in a 
minor way with the inorganic foods, more emphasis being given to the 
organic compounds which could be used as a source of carbon. It was early 
recognized, however, that for a detailed study of any fungus the food 
supply had to be fairly definitely controlled and that synthetic solutions 
rather than plant decoctions should be used. 
Of the commonly used synthetic solutions, that developed by Raulin 
(12)2 is the earliest. The solution contains most of the elements found 
in the ash of fungi. For the most part it was developed to meet the re- 
quirements for the growth of Aspergillus niger and of some other strict 
saprophytes. 
^ Contribution from the Department of Botany, Michigan Agricultural College. 
2 Raulin's synthetic solution: 
Ammonium nitrate 4.0 g. 
Ammonium phosphate 0.6 g. 
Ammonium sulphate 0.25 g. 
Potassium silicate 0.07 g. 
Potassium carbonate 0.4 g. 
Zinc sulphate 0.07 g. 
Ferric sulphate 0.07 g. 
Magnesium carbonate 0.4 g. 
Saccharose 70.00 g. 
Tartaric acid 4.00 g. 
Water 1500.00 cc. 
459 
