INULASE FORMATION IN ASPERGILLUS 



123 



lent in carbon content to 1% of glucose; series D containing 0.1% 

 of glucose and inulin equivalent in carbon content to 1.9% of 

 glucose ; and series E containing inulin only, equal in carbon con- 

 tent to 2% of glucose. The results of this experiment parallel 

 very closely the results set forth in table 7. If inulin is present 

 in concentrations of about 1% or more, very little decrease in 

 inulase formation is observable due to the presence of glucose. 

 The slight decrease in the results from series E to series C may be 

 due to a decrease in the amount of inulin present. However, 

 the results of series A and B show that 0.1% of inulin is below 



TABLE 8 

 Showing the effect of inulin in the -presence of glucose on inulase formation 



FUNGAL PREPARATIONS FROM CULTURES USING SOURCES 

 OF CARBON LISTED BELOW 



Series A (Glucose 2%) 



Series 5 (Glucose 1.9% + inulin 0.1%) 



Series C (Glucose 1% + inulin 1%) 



Series D (Glucose 0.1%> + inulin 1.9%) 

 Series E (Inulin 2%)... . 



PERCENTAGE OF HYDROL- 

 YSIS OF INULIN BY 

 EQUAL UNITS OF FUN- 

 GAL ENZYME PREP.*.- 

 RATION8 



per cent 



25.27 



20.48 

 93 09 

 95 92 



the limit of efficiency of inulin as a stimulus to inulase produc- 

 tion and that somewhere between 0.1% and 1% one would ex- 

 pect to find a point where the stimulatory effect of inulin first 

 becomes apparent. The numerical data for the last experiment 

 are presented above. The time of digestion was four hours. ^ 



E. DISCUSSION AND THEORETICAL CONSIDERATIONS 



As stated above, the purpose of this investigation has been to 

 demonstrate in a quantitative as well as a qualitative way the 

 formation of an enzyme in a living organism. The choice of inu- 

 lase, as to the enzyme to be studied, presented both advantages 

 and disadvantages. Inulin itself has been little studied and its 



^ The concentration of all the fungal extracts used in this experiment was con- 

 siderably greater than that used in previous experiments, which accounts for 

 the relatively great amount of hydrolysis in four hours. 



THE PLANT WORLD, VOL. 21, NO. 5 



