NUTRITIONAL FACTORS IN THE GROWTH OF CERTAIN 

 YEASTS AND BACTERIA.f 



I. VlTAMINES. 

 By LOUIS FREEDMAN 



Biochemical Laboratory of Columbia University at the 



College of Physicians and Surgeons, New York City, 

 and the Research Laboratory of H. A. Metz, Ne<w York City. 



INTRODUCTION. 



Since the discovery of Wildier's yeast stimulating "bios" in 

 1901, rapid progress has been made in determining the nutri- 

 tional requirements of various yeasts and bacteria. 



The early work of many investigators has shown that both 

 yeasts and bacteria require for their growth certain unknown 

 substances, the properties of which correspond closely to those 

 of our present day water-soluble B vitamine. Of late, however, 

 considerable discussion has arisen regarding the identity of the 

 substance that promotes the growth of yeast cells with that oi' 

 vitamine B, and also its relation to the substance that stimulates 

 the growth of bacteria. 



In the present work, the authors have made an attempt to 

 remove some of the uncertainties regarding these factors, and 

 to show that a close nutritive analogy exists between yeasts 

 and bacteria. 



EXPERIMENTAL PROCEDURE. 



A strain of hemolytic streptococcus, which was kindly fur- 

 nished by Dr. Mueller,** was used. The medium for the growth 



t Read before the Society for Experimental Biology and Medicine, New York City, 

 February IS, 1922. 



** The authors are indebted to Dr. T. Howard Mueller of the Department of Bacteriology, 

 College of Physicians and Surgeons, for the use of a strain of streptococcus, and for a 

 description of the preparation of his media, and of the technique of carrying out the bac- 

 teriological tests. 



