RepriDted from The Jochnal of Biolooic*i. Chemibtby, Vol. XIV, No. 3, 1913. 



TANNIC ACID FERMENTATION. II. 



EFFECT OF NUTRITION ON THE PRODUCTION OF THE ENZYME 



TANNASE. 



By lewis KNUDSON. 



(From the Laboratory of Plant Physiology, Cornell University, Ithaca, New 



York.) 



(Received for publication, January 30, 1913.) 



I. PREFACE. 



In an investigation upon tannic acid fermentation reported in 

 the previous paper, it was found that when cane sugar and tannic 

 acid are offered simultaneously to either Aspergillus niger or 

 Penicillium sp., the sugar is utilized as the source of carbon while 

 the tannic acid is fermented, gallic acid resulting. Some of the 

 results indicated that the rate of fermentation was influenced by 

 the concentration of the sugar. It was deemed important, there- 

 fore, to determine if varying the relative amounts of tannic acid 

 and sugar in'the nutrient solution has an influence upon the amount 

 of the enzyme tannase produced in the fungus thus grown. Since 

 tannic acid is probably not commonly utilized in nature by 

 Aspergillus niger and Penicillium sp. as a source of carbon, experi- 

 ments were also made to determine if the enzyme is produced when 

 the fungus is cultivated on nutrient solution lacking tannic acid. 



The writer wishes to acknowledge his indebtedness to Prof. B. M. 

 Duggar for assistance received during the course of the investiga- 

 tion. 



II. INTRODUCTION. 



Regulatory production of enzymes. Historical. A number of investiga- 

 tions have been made on the regulatory formation of the enzymes, but for 

 the most part conclusive investigations are lacking. Experimenting with 

 two species of bacillus, Brunton and MacFaydeni found that when culti- 



1 T. Lauder Brunton and A. MacFayden : The Ferment Action of Bac- 

 teria, Proc. Roy. Sac, xlvi, B, pp. 543-553, 1899. 



i8S 



