﻿1903] EXPERIMENTAL STUDIES ON INULASE 27 



yeast. It has proved to be a good method for obtaining 

 very active preparations of the invertin of yeast, and was there- 

 fore tried as a method for obtaining inulase from Penicillium 

 and Aspergillus. 



The Penicillium powder was examined first and was tested as 

 follows. A few milligrams of the powder were ground with 

 sand and water, and the mixture added to two test tubes con- 

 taining a solution of inulin together w^ith a little toluol. One of 

 these tubes was boiled and both were placed in the incubator. 

 After ten hours a very slight reducing power w^as observable in 

 the unboiled solution. After forty-four hours equal quantities 

 of the boiled and unboiled fluids were tested with the same 

 quantity of Fehling's solution. The result was striking, there 

 being a copious red precipitate of cuprous oxide in the test of 

 the unboiled digestion, and a clear blue liquid in the other. 

 Some of the liquid from the unboiled digestion was filtered and 

 an osazone made. It was apparently glucosazone. 



Experiments showed that this Penicillium powder would not 



yield a reducing sugar on auto-digestion, that it was without 



action upon a starch paste which was rapidly digested by saliva, 



but that it would invert cane sugar. The action of Penicillium 



powder on inulin, however, was not due to an ordinary invertin, 



since the invertin of yeast was found to be without action upon 

 inulin. 



The Aspergillus powder possessed a rather stronger inulin- 

 splitting power than the Penicillium powder. 



A number of attempts were made to obtain inulase from the 

 culture fluids in which Penicillium and Aspergillus had been 

 grown. The fluid itself, both before and after removal of 

 e sugar by dialysis, failed to show any power to hydrolyse 

 inulin. The precipitate thrown down in the culture fluid by 

 alcohol contained no inulase. Attempts were made to make 

 use of the well-known property of enzymes — of being carried 

 down by precipitates of neutral salts formed in their solutions. 

 Precipitates of barium sulphate, calcium sulphate, or calcium 

 oxalate thrown down in portions of the culture fluid had no 

 power to act on inulin. From these facts it is probable that 



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