KLUYVER S CONTRIBUTIONS TO MICROBIOLOGY AND BIOCHEMISTRY 



In the above-mentioned modification this experiment is conducted 

 with two such tubes. When it has been ascertained that after turning 

 the tubes upside-down the luminescence persists in both tubes for 

 approximately the same length of time, a small amount of cyanide is 

 added to one of the tubes, and after the suspensions have once more 

 become non-luminous, both tubes are simultaneously inverted. The 

 immediately observable intensity of the light emission is not per- 

 ceptibly different in the two tubes; but in the tube with cyanide the 

 luminescence lasts very much longer, demonstrating that the oxygen 

 supply, through inhibition of the respiration, disappears at a greatly 

 reduced rate. 



Another important contribution of this group was the unequivocal 

 demonstration with the aid of luminous bacteria that, contrary to 

 what had been claimed by Keilin and Hartree, oxygen is not required 

 for the decomposition of hydrogen peroxide by catalase. In a gas-tight 

 apparatus, in which the absence of even trace amounts of oxygen 

 could be guaranteed by virtue of the fact that a suspension of lumi- 

 nous bacteria failed to emit light, catalase and hydrogen peroxide 

 were mixed. This resulted in the instantaneous reappearance of lumi- 

 nescence, signifying that oxygen was being produced, and hence that 

 the enzymatic decomposition of the peroxide does not depend on the 

 presence of free oxygen. Afterwards Keilin and Hartree found that 

 their original contention was based on a misinterpretation of their 

 experimental results, and that these were caused by the inactivation 

 of the catalase by toxic nitrogen-oxygen compounds that were present 

 in the gas they had used to render their apparatus oxygen-free. 



In the preface to his lectures at Harvard University on the anatomy 

 of science, G. N. Lewis, one of the great philosopher-scientists of this 

 century, stated that 'the strength of science lies in its naivete'. This also 

 holds for Kluyver's biochemical speculations and generalizations, and 

 he was himself fully aware of it, as is shown by his use of Lewis' phrase 

 as the motto for the preface to his own London lectures. The attribute 

 of strength of these biochemical concepts is amply evident from the 

 fact that, in reducing the whole of biochemistry to a very small num- 

 ber of reaction patterns, a great simplification was achieved which also 

 permitted inferences with respect to some hitherto enigmatic bio- 

 chemical processes that thereby appeared in a fundamentally new 



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