SECRETION OF DIASTASE BY PENICILLIUM CAMEMBERTII 257 
Table X 
Fusarium sp. 
Mucor Rouxii 
Aspergillus 
(Jryzae 
Penicillium , 
Camembertii 
Medium 60 Cc. 
Time for 
Digestion 
(Days) 
Dry 
Weight 
of My- 
celium 
(Mg.) 
Time for 
Digestion 
(Days) 
Dry 
Weight 
of My- 
celium 
(Mg.) 
Time 
for Di- 
gestion 
(Days) 
Dry 
Weight 
of My- 
celium 
(Mg.) 
Time 
for Di- 
gestion 
(Days) 
Dry 
Weight 
of My- 
celium 
(Mg.) 
.4 percent 
starch .... 
-K 
249+ blue 
II 
10 
18.7 
10.6 
249+ blue 
121 
10 
10 
7 
7 
19 
7 
•4 
8.0 
23 
6 
1.4 
3-1 
12.3 
2.2 
-N 
249+ brown 
9 
249+ purple 
74 
42 
68 
10 
13.6 
3-4 
3-4 
20.4 
14.9 
15-6 
159 + 
6 
-Mg 
37-2 
41.9 
34-8 
53-7 
45-4 
10 
-P 
II 
34-1 
10 
5 
6 
5-3 
16.8 
-S 
13 
II 
10 
6 
-Fe 
24 
23 
40.0 
44.6 
7 
7 
6 
I3-I 
14.4 
Full nutrient. . 
10 
6 
very slowly in the absence of nitrogen; and Aspergillus Oryzce and 
Penicillium camembertii, which digest starch fairly rapidly in the 
absence of all nutrients. 
It may also be noted that there is little correlation between the 
time required for digestion and the dry weight of the fungous mycelium. 
In the case of Penicillium camembertii, the same time (6 days) is re- 
quired to digest approximately .24 g. of starch in the cultures lacking 
potassium, magnesium, phosphorus, sulphur, and iron, and in the full 
nutrient, but the dry weight of the mycelium in these cultures varies 
from 2.2 mg. to 16.8 mg. Somewhat similar results are shown by 
the data obtained with the three other fungi. 
Discussion. — An examination of the complete data obtained in the 
experiments with nutrient cultures shows that again we have no 
evidence to demonstrate that potassium is concerned with diastase 
formation. With the exception of those cultures in which nitrogen 
was lacking, there are no marked differences in the times required for 
the starch digestion. It is significant, as shown in Table X, that a 
longer period is required for starch digestion by the fungus when grown 
in the culture medium lacking nitrogen only, than in the medium 
lacking all nutrients. It was found that the combination of salts 
used in the minus nitrogen medium decreases the time required for 
Taka diastase to change a given quantity of starch to the point 
at which it no longer colors with iodine. The longer period of time 
required for digestion in the minus nitrogen culture medium is, there- 
to Dry weight not determined. 
