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AUGUSTO BONAZZI 



presence of oxygen. It is also reasonable to assume that the 

 energy resulting from this oxidation is utilized in further growth. 

 If this were actually the case, it should be possible to follow these 

 various steps and the coincident disappearance of sugar at close 

 intervals of time, in a solution imdergoing active fermentation. 



TABLE 9 



Results of gas analyses of cultures of Azotobacter under oxygen starvation expressed 



in percentage of the gas mixture 



TABLE 10 

 Gas and sugar changes in cultures of Azotobacter 



TABLE 11 

 Gas balances in cultures of Azotobacter chroococcum 



This method of study has been followed by Allen (1920) with 

 the results diagrammatically shown in the figure 4. 



The sharp fall of the sugar contents during the period 0-X' 

 from the quantity Y to Y' shows without doubt that the sugar 



