Feb. is, 1921 



Amylase of Rhizopus tritici 



771 



and e, it might be assumed that the accumulation of reducing sugars 

 acted as a paralyzer to further action of the enzym or, as has been sug- 

 gested by some investigators, the enzym entered into combination with 

 the products of the hydrolysis and consequently became inactive. 



Table VII. — Amount of 1.5 per cent starch paste used, total reducing sugars, and reduc- 

 ing sugars per 10 cc. 



In the series of experiments reported in Table VIII different amounts of 

 a 1 per cent starch paste solution were used, and enough water was added 

 to make a total volume of 500 cc. One-fourth gm. of enzym powder was 

 added to each set of flasks. The time of hydrolysis was 1 8 hours at 40 C. 



Table VIII. — Amount of 1 per cent starch paste used, total reducing sugars, and reducing 



sugars per 10 cc. 



Reducing 

 sugars per 10 

 cc. of solution. 



Mgm. 



3- ^50 

 6. 3050 



8- 9375 



10. 4000 



11. 9600 



12. 1550 

 8- 1575 



Total reducing 

 sugars. 



Mgm. 

 159. 250 

 315- 250 

 446. 875 

 520. OOO 

 598. OOO 

 607. 750 



407. 875 



The amount of reducing sugars per 10 cc. increases with the increase 

 in the amount of starch from sample a to sample f and then decreases. 

 An approach toward the end point might here also account for the lesser 

 amount of hydrolysis in the more dilute solutions if the total reduction 

 in sample g, which contains the largest amount of starch, was not actually 

 less than in several of the other samples. 



A final series of experiments was carried out in which the total volume 

 of 0.5 per cent starch paste was varied but the amount of enzym powder 

 (0.25 gm.) was constant. Hydrolysis was carried on for 18 hours at 

 40 C. (Table IX.) 



There was a decrease in the reducing sugars per 10 cc. and an increase 

 in total sugars as the volume of the solution increased from sample a to 

 sample e, and then a reverse of the process. 



