202 



Journal of Agricultural Research voi. xviii. no. 4 



A similar phenomenon is to be observed when 20 cc. of spores are 

 employed. This is in line with the theoretical considerations of the 

 activity of the enzym invertase and indicates that the amount of 

 inversion depends upon the quantity of sucrose present. The polari- 

 zation values do not permit of such clearly defined generalization 

 because of the more complex nature of the factors involved. 



The procedure described above was repeated, using the spores of 

 Penicillium expansum as an inoculum; and the results are recorded in 

 Table VI. The calculations for diminished and increased dilution 

 depending upon the amount of inoculum added have been incorporated. 



Table VI. — Analyses of 10 and 20 per cent sugar solutions inoculated with spores of 



Penicillium expansum 



10 PER CENT SUGAR SOLUTIOxN 



20 PER CENT SUGAR SOLUTION 



10 CC. sterile water heated to 63° C. 

 10 cc. sterile water heated to 100° C 



10 cc. spores heated to 100° C 



5 cc. spores heated to 63° C 



10 cc. spores heated to 63° C 



20 cc. spores heated to 63° C 



73-2 

 73-2 

 73-2 

 73-2 



73- o 

 72. 6 



.6 



o. 01^ 

 • 15 



o. 04 



.04 

 .04 

 .06 



• 15 



• 23 



o. 02 

 II 



.19 



It will be readily observed that with 5 and 10 cc. of inoculum no 

 inversion took place in a 10 per cent sugar solution, and only a very 

 slight increase in reducing sugars is to be found where 20 cc. were used. 

 The inoculum contained 600,000 spores per cubic centimeter and 

 exhibited no optical activity. However, where a 20 per cent solution was 

 employed the reducing sugars increased with an increase in inoculum, 

 while there was a substantial decrease in polarization and percentage of 

 sucrose with the largest inoculum. 



The increase in inversion which occurred with an increase in incubation 

 period is not large and is in agreement with the facts which were noted 

 after three hours' incubation. Thus it may be inferred that the spores 

 of Penicillium expansum have a relatively slight invertase content. 



