F. W. TANNER 501 



field. Different species of buckling fungi have been used. Some of the experiments 

 have been contaminated with Imcteria since the inocuhmi was Fleischmann's yeast. 

 It was also shown that a distinction should be made between growth and multiplica- 

 tion. Eddy and his colleagues reported a variation in response to their Bios 223 be- 

 tween a top and bottom yeast, as did Zadjel and Funk. 



Tanner and his colleagues also stated that some yeasts will not grow in certain 

 media because the medium does not supjily the necessary food constituents. The 

 addition of a su])posedly rich bios material may supply these necessary constituents 

 and the stimulation in growth which might result from the addition of small amounts 

 of chemically known substances might be attributed to a hypothetical substance. 

 When a yeast cell 5 micra in diameter contains only 0.000,000,009,817,5 mg. of solid 

 matter, it is easy to recognize that minute traces of organic or inorganic matter 

 might be sufficient to initiate multii)lication. After multiplication has started, other 

 factors might enter to cause it to continue. 



Werkman' reported that fourteen strains of Saccharomyces cercvisiac grew and 

 reproduced continuously. The important factor in these experiments was that in- 

 stead of cane sugar which has frequently been pointed out as the bios-contributing 

 factor, synthetic methose was used. Werkman stated that bios was not necessary for 

 yeast growth. This is a significant report since it is one of the few attempts to utilize 

 synthetic carbon compound in place of sucrose. It refutes decisively the reports that 

 growth in mineral salt-sugar media is made possible by bios in the sugar. Other con- 

 tributions to the bios question were also made by Susuki and Taira.^ 



CHEMISTRY OF ALCOHOLIC FERMENTATION 



The history of the theories of alcoholic fermentation is well reviewed by Harden,^ 

 Schoen,^ and Nord.^ 



Neuberg"^ observed that salts of pyruvic acid (CH3COCOOH) are fermented by 

 veast to acetaldehyde and carbon dioxide. This change was supposed to be due to an 



enzyme, "carboxylase," which could remove the C — portion of the carboxyl group 

 of pyruvic acid, thus forming acetaldehyde. Carboxylase was believed to be asso- 

 ciated with zymase. Consequently, Neuberg was led to believe that pyruvic acid 

 and acetaldehyde were intermediate products in alcoholic fermentation. In order to 

 show this, Neuberg suggested the following equations: 



I. C6H,.06— 2H.O = 2CH3— CO— COH 



Glucose Methylglyoxal 



" 2. CH3— C(OH) — COH + H, 1 \ CH.OH— CHOH— CH.OH Glvcerol 



CH3-~C(0H)— COH Oj [ CH3C(OH)3— COOH Pyruvic acid (hydrated) 

 A hvdiated mflhy'gl\'Oxal 



' Werkman, C. H.: Science, 62, 115. IQ25. 



- Susuki, B., and Taira, T.: /. Chem. Soc, Japan, 45, 299-311. 1925. 



■'Harden, A.: Alculiolic Fc/mcnlation. London: Longmans, Green & Co., 1923. 



^ Schoen, M.: Le proMeme des fermentations. Paris: Masson et Cie., 1926. 



5 Nord, F. F.: Cheni. Rev., 3, 41-79. 1926-27. 



* Neuberg, C: Ber., 55, 3624-38. 1922. 



