AMYLASE IN THE SPORES OF RHIZOPUS TRITICI 
AND RHIZOPUS NIGRICANS 
L. L. Harter and J. L. Weimer 
(Received for publication April 28, 1922) 
Introduction 
The results obtained by a number of investigators have demonstrated 
that many fungi secrete enzyms, which diffuse out of the mycelium into 
the substrate, where certain cleavage products are formed. 
However, Kopeloff and Kopeloff (3) seem to have been the first to study 
the enzyms of fungous spores. These workers found that the spores of 
Aspergillus niger, A. sydowi, and to a lesser extent Penicillium expansum 
and A. flavus contain an enzym which hydrolyzes cane sugar. Their 
results show that the deterioration of cane sugar may depend, in part at 
least, on the action of the spores of some of the mold fungi. The enzymic 
activity of the spores, previously killed by heating for 30 minutes at 63° C., 
was determined by suspending them in cane-sugar solution of known 
strength and determining the cleavage products by polarization. The rate 
of hydrolysis of the cane sugar was found to be correlated with the number 
of spores present in the system. 
It is the purpose of this paper to record the data obtained relative to 
the occurrence of amylase in the spores of Rhizopus nigricans Ehrnb. and 
R. tritici Saito. 
Methods of Experimentation 
Since the mycelium of Rhizopus tritici has been shown to produce an 
amylase (2), it was imperative that the spores be completely separated from 
it before this enzym could be studied. Preliminary experiments showed 
that spores were produced abundantly and that they could be readily 
separated from the mycelium if the fungi were grown on sweet-potato 
decoction; hence this medium was employed. About 750 cc. of the solution 
were used in 2-liter Erlenmeyer flasks. On this medium a luxurious 
growth is made in from 5 to 10 days at temperatures ranging from 22 0 to 
35 0 C. The spores, although abundantly produced in about 5 days, sepa¬ 
rated from the mycelium much more readily after about two weeks’ growth; 
hence cultures of this age were used. At the end of the growth period, the 
fungus, which formed a thick felt floating for the most part on the surface 
of the medium, was carefully removed from the flasks. The bottom of 
the felt was held under a stream of running water in order to remove the 
culture solution. It was then floated top down in a dish of distilled water 
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