1 



176 



PHYSIOLOGY OF THE FUNGI 



Fig. 32. Method of detecting multiple vitamin deficiencies of yeasts. Failure to 

 grow in the absence of a particular vitamin indicates a deficiency if the culture grew in 

 a medium supplied with a combination of vitamins. Growth of a strain of Saccharo- 

 myces cerevisiae (above) and Mycoderma valida (below) after 5 days at 25°C. From 

 left to right the vitamin supplements were: Tube 1, none; 2, less thiamine; 3, less 

 pantothenic acid; 4, less pyridoxine; 5," less inositol; 6, less bio tin; 7, less nicotinic 

 acid ; 8, all six vitamins. 



