irY 





STUDIES ON CULTURAL REQUIREMENTS OF 

 BACTERIA. I 



J. HOWARD MUELLER 



Fro?n the Department of Bacteriology, College of Physicians and Surgeons, 

 Columbia University, New York 



Received for publication November 1, 1921 

 INTRODUCTION 



With the exception of a few such media as Uschinsky's and 

 Frankel's, which are of interest only from the fact that they 

 demonstrate the abihty of certain species of bacteria to syn- 

 thesize protein and other complex physiological substances from 

 simple salts, all the pathogenic bacteria are cultivated for prac- 

 tical purposes on empirical mixtures containing infusions of 

 meat, the digestion products of protein and so forth. Most 

 pathogens either fail to grow, or produce very scant growth on 

 simple synthetic media. Many fail to multiply even on meat 

 extract-peptone media, but flourish after the addition of serum, 

 blood, and similar materials. It occasionally happens that a 

 lot of stock media, prepared with all due regard to known com- 

 ponents and hydrogen ion concentration will fail to grow such 

 organisms as pneumococci, although other lots prepared in the 

 same way have been successful. 



Numerous attempts have been made to amplify the use of 

 sjTithetic media by the addition of known compounds as a source 

 of nitrogen or of some particular chemical grouping which has been 

 suspected of playing a part, but as far as progress in the direction 

 of routine cultivation of bacteria on media of known composi- 

 tion is concerned, the results have been uniformly disappointing. 

 On the other hand, there seems to have been very little effort 

 made to attack the problem from the angle of an analysis of the 

 basic factors supplied by the physiological mixtures which are 



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JOCBNAI. or BACTBRIOLOOT, VOL. VU, KO. 3 



