798 



ENZYME ACTION 



Tannase. 



Under the action of tannase, digallic acid is probably converted 

 into gallic acid in accordance with the general formula, 



C14H10O9 - H2O = 2C6H2(OH)3COOH 



Whether or not this reaction took place was determined by titrating 

 the filtrates against 0.05 N iodine after the digallic acid had been 

 precipitated out by the addition of albumin and the albumin salted 

 out with NaCl. As indicated in Table III, the results are negative; 



TABLE II. 



Glucosidase Action of Poly par us volvatus and Fomes igniarius. 



1 per cent salicin + fungous meal 



1 " " " 4- " " autoclaved 



1 <( a i( 



Polyporus 

 volvatus. 



Fomes igniarius. 



O.OSNKMn04 



15.15 

 4.50 

 0.40 



TABLE III. 



Tannase Action of Polyporus vovatus and Fomes igniaritis- 



The absence of tannase in Polyporus volvatus is difficult to account 

 for since the fungus inhabits the barks of trees having a high tannin 

 content. Its absence may, however, be due to the fact that the 

 culture medium upon which it had been grown contained little or no 

 tannin. The influence of the culture medium on the production of 

 tannase in fungi has been fully investigated by Knudson.'' 



^Knudson, L., Tannic acid fermentation. I, /. Biol- Chem-, 1913, xiv, 159, 

 Figs. 1 and 2; Tannic acid fermentation. II, 185. 



