Feb., 1923] 
HARTER AND WEIMER — AMYLASE IN RHIZOPUS 
91 
from the filter paper in 30 cc. of water and extracted for three hours at 25 0 . 
After thorough shaking in order to obtain as uniform a distribution of the 
spores as possible, 10 cc. were pipetted off into each of two flasks, thus 
making three flasks each containing an equal amount of the spore suspension. 
To one flask (A) were added 40 cc. of a 0.5 percent starch-paste solution. 
A like amount of starch-paste solution was placed in the second flask ( B ), 
which was then steamed for 10 minutes to inactivate the enzym. To the 
third flask (C) 40 cc. of sterile distilled water were added. Hydrolysis was 
carried out for 18 hours at 38°. Results (average of several tests) expressed 
in milligrams of reducing sugars per 100 cc. of solution were obtained as 
follows: A, 105.3; B, o; C, o. 
Experiment 2 
Organism, Rhizopus tritici. The purpose of this experiment was to show 
that the enzym is produced in the spores at any temperature at which the 
fungus will grow. The exact quantity of spores used in these experiments 
was not determined. Cultures of the organism were grown at three temper¬ 
atures, 9 0 , 30°, and 40° C. At 9 0 no fruiting took place, but at temperatures 
of 30° and 40° spores were abundantly produced. The spores were ex¬ 
tracted for 3 hours in io cc. of water. Digestion of starch (50 cc. of a 0.5 
percent starch-paste solution) was carried out for 18 hours at 38°, with the 
following results expressed in milligrams of reducing sugars per 100 cc. of 
solution: 30°, 163.8; 40°, 256.1. There were more reducing sugars formed 
by the spores from a culture grown at 40° than from one grown at 30°. 
However, this does not necessarily mean that spores produced at the higher 
temperature have a greater hydrolyzing power, since there may have been 
more spores present in the system. It does mean, nevertheless, that spores 
produced at such a temperature are capable of hydrolyzing starch to sugar. 
Experiment 3 
Experiment 3 represents the average of a number of parallel tests in 
which the amounts of the reducing sugars formed are expressed in milligrams 
per 100 cc. of solution. The exact weight of the spores was determined 
in each case, and the amount of starch hydrolyzed was calculated for 0.25 
gram of spores. 
Table i. Amount of reducing sugars formed in a solution of starch paste by the spores of 
Rhizopus tritici and R. nigricans , expressed in milligrams per 100 cc. of solution 
Temperature (° C.) Rhizopus tritici Rhizopus nigricans 
22 to 25. 335-35 103.23 
30 . . 215.00 
38 . 189.49 - 
The spores were prepared according to the method already described. 
They were extracted in 20 cc. of sterile distilled water for 3 hours. After 
the addition of 80 cc. of a 0.5 percent starch-paste solution, digestion was 
carried out for 18 hours at 38° C. The reducing sugars formed in the system 
