BIOGRAPHICAL MEMORANDA 



Furthermore, these analytical data indicated that part of the two- 

 carbon products must have originated by a different mode of sugar de- 

 composition, which would not imply the formation of an equivalent 

 amount of one-carbon products ; and this was conveniently provided 

 by the postulated degradation to two-and four-carbon fragments, the 

 latter being the immediate source of the succinic acid. And because 

 the quantitative relations between the amounts of succinic acid, two- 

 carbon compounds, and one-carbon products closely agreed with 

 those predicted on the basis of an assumed simultaneous occurrence 

 of both a symmetrical and an asymmetrical cleavage of the sugar, this 

 was consequently considered as conclusive evidence in favour of the 

 mechanism proposed by Virtanen. 



It will be obvious that this kind of reasoning is pertinent only as 

 long as the one-carbon fragments produced in the course of the 

 fermentation do not undergo subsequent changes by which they are 

 converted into substances with more carbon atoms. The above- 

 mentioned investigations of Wood and Werkman on the actual dis- 

 appearance of carbon dioxide during a fermentation suffice, however, 

 to render the above argument invalid. 



However great the jolt may have been, Kluyver quickly rallied to 

 the new situation. In a lecture delivered in Helsinki in 1939 he re- 

 viewed the recent developments concerning the participation of car- 

 bon dioxide in the metabolism of heterotrophic micro-organisms and 

 their implications; it was on this occasion that he ventured the remark: 



'Under these circumstances we may well ask . . . whether we should 

 not make ourselves familiar with the idea that even the cells of certain 

 animal organs can assimilate carbon dioxide. 



'If at present a lecturer were to proclaim that the cattle in the 

 pasture, nay, even the members of his audience assimilate carbon 

 dioxide, he may expect to be showered with energetic protests. Never- 

 theless, the temptation to do so is certainly not easy to resist!' (p. 86). 



In this lecture Kluyver also discussed certain experimental results 

 of his collaborator, Hes, who had shown that suspensions of various 

 micro-organisms failed to metabolize in a rigorously carbon dioxide- 

 free environment. In trying to account for this fact Kluyver considered 

 a number of possibilities without, however, reaching a satisfactory 

 conclusion. This is not surprising ; it was not until the role of the di- 

 carboxylic acids in oxidative metabolism, and particularly in the tri- 



