KLUYVER S CONTRIBUTIONS TO MICROBIOLOGY AND BIOCHEMISTRY 



ger [1936TI1], conducted numerous comparable experiments with 

 various Spirillum species. The report of this investigation contains an 

 interesting discussion in which the notion of a 'chip respiration' was 

 launched. This term was introduced to convey the idea that the oxi- 

 dative dissimilation of a substrate might represent mainly a whittling 

 down of its molecules to fragments that could be used as appropriate 

 building blocks for the synthesis of cell materials. The parts that were 

 intrinsically unsuited for this purpose would thus be eliminated as 

 'chips', generally in the form of carbon dioxide. The experimental 

 results were, however, not entirely consistent with this idea; some of 

 the over-all equations, expressing the quantitative relations between 

 the amounts of substrate used, oxygen consumed, carbon dioxide 

 evolved, and 'assimilation products' formed, were difficult to inter- 

 pret in this manner. The only conclusions that could safely be drawn 

 from the data were that the oxidative degradation of an organic sub- 

 strate is quite generally accompanied by a massive assimilatory activ- 

 ity, and that, even in the absence of assimilable nitrogen compounds, 

 when protein synthesis and hence cell multiplication is precluded, a 

 variety of assimilation products may be formed. 



Shortly afterwards Clifton [1937], in Kluyver's laboratory, extended 

 these studies, and discovered that this assimilatory activity can be pre- 

 vented if the resting cell suspensions are exposed to low concentrations 

 of dinitrophenol or sodium azide, which do not appreciably inhibit 

 the oxidation of the substrates. Evidently the connexion between de- 

 gradation and synthesis is severed under the influence of these com- 

 pounds. Not until more than a decade later Loomis and Lipmann 

 [1948] found an explanation for this effect by showing that dinitro- 

 phenol blocks the formation of adenosine triphosphate that normally 

 results from the transfer of phosphate from phosphorylated inter- 

 mediate products such as acetyl phosphate. In current terminology, 

 and entirely in keeping with Kluyver's concept of the nature of bio- 

 synthetic processes, this can be paraphrased by saying that under 

 these conditions the necessary raw materials for anabolic reactions are 

 prevented from being formed during the oxidation of the substrates. 



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