KLUYVER S CONTRIBUTIONS TO MICROBIOLOGY AND BIOCHEMISTRY 



even more during the subsequent filtration and washing, the li- 

 ving substance undergoes selfdestruction.' [Kluyver and Struyk, 1928. 

 p. 258]. 



It is not difficult to understand that this investigation decided 

 Kluyver against undertaking any further studies in the field of coen- 

 zymes. And, despite the great advances in our knowledge of bio- 

 chemical reaction mechanisms resulting from the eventual isolation 

 and chemical identification of various coenzymes - advances that 

 Kluyver fully appreciated and readily acknowledged - he never quite 

 lost his earlier dislike for such studies. Even as late as 1954, in the 

 second of the Harvard lectures, he conceded this in the passage: 

 '. . . it is tempting to say a few words about the significance of the 

 discovery of a coenzyme being involved in a certain reaction step. I 

 have to confess that my first mental reaction on hearing of such a 

 discovery is to lower the flag to half-mast' (p. 47). 



An additional effect of this study on 'the so-called coenzyme of al- 

 coholic fermentation' was to strengthen still more his belief that 

 studies with enzyme extracts were not apt to contribute much to bio- 

 chemical comprehension. Even if - and this was doubtful enough in 

 the 'twenties - better techniques could be invented for the prepara- 

 tion of cell-free extracts, it seemed to him improbable that studies 

 with such extracts would contribute anything beyond what had al- 

 ready been inferred from investigations with intact organisms. The 

 studies on the cozymase problem afforded an instructive example; it 

 was the previously developed theory of alcoholic fermentation that 

 had led to predict what the coenzyme should be and do, and this had 

 been supported by experiment. Meanwhile, these same studies had 

 failed to provide a deeper insight into the mechanism of the process, 

 and rather emphasized the disadvantages inherent in working with 

 extracts in which the harmonious cooperation of various principles 

 had been deranged. On the other hand, the concept that the essence 

 of biocatalysis was the activation and transfer of hydrogen suggested 

 that a more fundamental approach could be devised which would 

 lead to a sounder organization and understanding of the various 

 manifestations of the chemical activities of living organisms. This was 

 developed in the last of the earlier mentioned London lectures. 



Here, Kluyver first argued that there is no ground for believing 

 that some biochemical events might not be mediated by enzymes, 



103 



