Reprinted from The Jodhnai, op Biological Chemistky, Vol. XIV, No. 3, 1913. 



TANNIC ACID FERMENTATION. I. 



By lewis KNUDSON. 

 ^From the Laboratory of Plant Physiology, Cornell University, Ithaca, N. Y.) 



(Received for publication, January 30, 1913.) 



I. PREFACE. 



During 1907-1908, a preliminary investigation of the conditions 

 of tannic fermentation was made by the writer with the purpose 

 of improving the practical methods involved. In the course of 

 this preliminary investigation a njimber of interesting observa- 

 tions were made, justifyhig-a further study of the conditions of 

 the fermentation and of^the relation of various organisms to the 

 process. With the progress of the investigation other phases 

 suggested themselves, until ultimately four distinct but correlated 

 parts of the subject were experimentally studied. Part I, here 

 reported, includes chiefly: (1) the toxicity of tannic acid for vari- 

 ous fungi; (2) a comparison of the organism Aspergillus niger and 

 Penidllium sp. in the fermentation of tannic acid; (3) the condi- 

 tions and influence of various factors on the fermentation process. 

 Part II is concerned primarily with the influence of nutrition on 

 the production of the enzyme tannase, and will be reported in a 

 subsequent paper. 



These investigations were begun at the suggestion of Prof. 

 B. M. Duggar and prosecuted in his laboratory. It is a pleasure 

 here to express my thanks for the advice, kindly criticism and 

 assistance, which he has so generously given. 



II. INTRODUCTION. 



Chemical nature of tannic acid. Wagner^ has grouped the 

 tannins into a "physiological" and a "pathological" series, the 

 latter including, as most important, the tannin of oak galls as 



'R.Wagner: Beitrage zur Kenntnis und zur quantitativen Bestimmung 

 der Gerbsauren, Zeitschr.f. anal. Chem., v, pp. 1-10, 1866. 



159 



THE JOURNAL OF BIOLOGICAL CHEMISTR1, VOL. XIV, NO. 3. 



