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506 BOTANICAL GAZETTE [DECEMBER 
has been investigated by GREzEs® with respect to the production of invertase 
and other enzymes by Aspergillus niger; and by Knupson with respect to the 
production of tannase by Aspergillus niger, Penicillium rugulosum, and an 
unknown species of Penicillium. 
GREZES finds that Aspergillus niger, even when grown on RAULIN’S solution 
containing no sugar and with succinic acid as the sole source of carbon, produces 
invertase, diastase, maltase, inulase, and emulsin. A quantitative study of the 
production of invertase by the fungus on media containing, on the one hand 
cane sugar and on the other succinic acid, a substance not related to the 
carbohydrate group, showed that the production of the enzyme is greatly 
influenced by the mode of nutrition. Only small quantities of invertase are 
produced by cultures on succinic acid, yet its production is not entirely sup- 
pressed, even after 60 spore-generations on succinic acid, and nearly normal 
production immediately takes place if the fungus is transferred to sugar solu- 
tions. The author concludes that the power of invertase production is an 
inseparable characteristic of the fungus 
Kwupson? finds that tannase is not produced by Aspergillus niger nor by 
the species of Penicillium which he studied if there is no tannic acid or its 
decomposition product, gallic acid, in the solution. If either of these sub- 
stances is present there is a progressive increase in the production of. tannase 
with increase of concentration of the acids. With a constant concentration of 
tannic acid the production of the enzyme is depressed with increasing concen- 
tration of sugar. Mycelia grown on various organic compounds other than 
gallic acid contain no tannase. Gallic acid stimulates the production of 
tannase even in solutions containing 10 per cent of cane sugar. 
A number of papers deal with the hydrolysis by fungi of glucosides, tannin, 
and other less complex compounds. UHLENHAUT® studied the hydrolysis of 
amygdalin by the action of fungi, but, aside from extending somewhat the list 
of fungi capable of splitting amygdalin, his paper adds nothing essential to 
that which is already known concerning the process. The 14 species which he 
investigated differed considerably, as hae by purely qualitative tests, in 
their capacity for hydrolyzing the glucoside. The mucors were in general found 
to be more active in this respect than the higher fungi. The growth of the 
mucors on amygdalin solutions was usually soon inhibited, owing to the 
accumulation of benzene cyanhydrin, to which the author ascribes the hydro- 
cyanic acid odor developed in the cultures. If, however, other fungi capable 
of utilizing the excess of cyanhydrin are grown in cultures together with mucors, 
° Grezes, G., Recherches sur la sucrase de VAspergillus niger. 
Pasteur 26: cis: 1912. 
7 Knupson, L., Tannicacid fermentation. II. Effect of nutrition on the produc- 
tion of the enzyme ote Jour. Biol. Chem. 14: 185-202. 1913. 
*Untennavt, H., Uber die Spaltung des Amygdalins durch Schimmelpise: 
Ann. Mycol. poke oer, IQII. 
Ann. Inst, : 


