192 



Nutrition and Tannase Production 



While a temporary precipitate of the diastase and tannic acid maj^ 

 exist, it is more reasonab'e to assume that the increase of diastase 

 must be ascribed to some other cause. Increased growth may 

 possibly occur, as a result of the addition of tannic acid, and with 

 this may be correlated an increase of diastase. 



A comparison of Asp&rgillus niger and PenicilUum sp. in the 

 formation of the enzyme tannase is of interest because it affords 

 a partial explanation of the relatively slower transformation of the 

 tannic acid by PenicilUum sp.^^ In both cases the amount 

 of tannase produced in a 0.1 per cent concentration of tannic 

 acid is the same. At 2 per cent concentration the amount of 

 galUc acid, resulting from the action of the Aspergillus powder, 

 was 3.88 times the transformation effected by the PenicilUum 

 powder. 



In the preceding experiment no attempt was made to determine 

 the amount of enzyme secreted into the nutrient solution, and an 

 experiment was required to determine this point as well as to verify 

 the preceding results. The methods of experimentation were 

 essentially the same as in the previous experiment except that 250 

 cc. Erlenmeyer flasks were employed with 100 cc. of the nutri- 



TABLE II. 



Aspergillus niger. 



Effect of concentration of tannic acid on the production of tannase, using 

 solution B -\- 10 per cent cane sugar + tannic acid. Average period of 

 incubation for mycelial powder, sixty-four hours; for enzyme excreted, 

 ninety hours. 



" Ibid. 



