Issued July 30, 1910. 



United States Department of Agriculture, 



BUREAU OF CHEMISTRY Circular No. 58. 

 H. W. WILEY, Chief of Bureau. 



THE EFFECT OF ALCOHOL ON INVERTASE. 



By C. S. HUDSON and H. S. PAINE, 



Assistant Chemists. 



PURPOSE OF THE INVESTIGATION. 



A knowledge of the action of alcohol on invertase is of practical 

 importance for two reasons; first, alcohol is naturally present during 

 the fermentation of cane sugar by yeast and the invertase of the 

 yeast is thus normally in the presence of weak alcohol; and, second, 

 alcohol is often used, though generally with little success, to prepare 

 the enzym in a solid form by precipitation from an aqueous extract 

 of yeast. In order to learn what influence alcohol of different 

 strengths has on invertase the following investigation was made. 

 The results show that the influence is exceedingly great and that it 

 consists in three distinct actions, namely, an inactivation, a perma- 

 nent destruction, and a precipitation of the enzym. These actions 

 will be described in the order named. 



THE INACTIVATION OF INVEBTASE BY ALCOHOL. 



The activity of purified invertase in inverting cane sugar dis- 

 solved in various strengths of ethyl alcohol was measured at 30 C. 

 by the usual method. Care was taken to have sufficient acetic acid 

 in the solutions to insure that the maximum activity of the enzym 

 was attained, and the solutions were made alkaline at the end of the 

 experiment to stop the enzymotic action and complete the mutaro- 

 tation. The alcohol used was Squibb's or Baker's absolute alcohol 

 and the concentrations were expressed as volume per cent. The 



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