UTILIZATION OF AMINO ACIDS AND AMIDES 



257 



No nitrogen 



DL-Tryptophan 



L-Cysteine 



L-Hydroxyproline 



L-Histidine 



L-Lysine 



DL-Methionine 



DL-Threonine 



DL-Leucine 



DL-Valine 



L-Asparagine 



DL-Aspartic acid 



L-Glutamic acid 



DL-Phenylalanine 



DL-lsoleucine 



L-Tyrosine 



DL-Alanine 



L-Arginine 



DL-Serine 



L-Proline 



Glycine 



Casein hydrolyxate 



20 



40 60 



Relative growth 



80 



100 



Figure 6. The growth of Venturia inaequalis in media with amino acids as the 

 source of nitrogen. Each value is the mean of 27 observations (3 concentrations, 3 

 incubation periods, and 3 replicates). Growth on casein hydrolyzate has been given 

 a relative value of 100. Drawn from tabular data of Pelletier and Keitt (409). 



fungi, they will not necessarily apply to any one fungus which happens 

 to be of interest. 



The data of Figure 6 show the range of utilizability of the common 

 amino acids for Venturia inaequalis. Statistical analysis of these and 

 other data shows that the apparent relative value of different amino 

 acids is affected by the period of incubation, the nature of the basal 

 medium, and the concentrations of amino acids used (409). Figure 

 6 also brings out the point that growth is usually better with a natural 



