io6 Indianapolis Biochemical Meeting: Abstracts [Sept. 



ing with yeast, wherein it is shown that there may be induced by 

 special nutrition an enzyme which did not occur normally in the 

 yeast plant. The work of the writer, herewith briefly reported, 

 is also in disagreement with the results of Dox. 



The two organisms, Aspergillus niger and PenicilUitm sp., which 

 normally develop on commercial gall nuts when these are moistened 

 and exposed to the air, produce the enzyme tannase ; and this enzyme 

 is capable of effecting the transformation of tannic acid into gallic 

 acid and glucose. 



Pottevin found that the enzyme tannase was formed in Asper- 

 gillus niger when it was grown in Raulin's Solution in which the 

 sugar was replaced by tannic or gallic acid. The writer has grown 

 the organism in synthetic Solutions in which the carbon nutrient, 

 cane sugar, was replaced entirely or supplemented by one of several 

 carbon Compounds. In the experiments the effect of each of four- 

 teen different carbon Compounds was tested, but the enzyme tannase 

 was produced only when the sugar was replaced by tannic or gallic 

 aci(^, or supplemented by tannic acid. The gallic acid, further- 

 more, was not as efficient as the tannic acid in stimulating the 

 formation of the enzyme. 



Some work has been done showing that the quantity of a par- 

 ticular enzyme produced irrespective of the character of the carbon 

 nutrient, can be increased in amount by offering the organism the 

 carbon Compound which is trans formed by the enzyme in question. 

 No work apparently has been reported on the effect of concentra- 

 tion of the trans formable substance on the quantity of the cor- 

 responding enzyme produced. Employing the two organisms men- 

 tioned, the writer made experiments, in which a modified Czapek's 

 Solution was the nutrient medium — in this the concentration of 

 sugar was made lo per cent., and it was supplemented by tannic 

 acid in concentrations varying from o.oi per cent. to lo per cent. 

 The quantity of the enzyme produced was augmented by increase 

 in concentration of the tannic acid. None, however, was formed 

 when the concentration of tannic acid was as low as o.oi per cent. 



Similar results were obtained with Penicillinni sp. Aspergillus 

 candidus, Aspergillus oryz<s and Penicillium granulatiim cultivated 

 in a synthetic Solution in which the carbon was supplied as 5 per 



