1915] 



DAVIS ENZYME ACTION IN MARINE ALGAE 



795 



periments, it was desired to know which, if any, were the 



most favorable substrates for the diastases of the 



The 



action of diastase from Viva lactuca was taken as an index 

 Potato, arrowroot, wheat, corn, and soluble starch, as well as 

 inulin, were made up in 1 per cent concentrations in the man- 

 previously described. To 50 cc. of each of these sub 



ner 



were added 10 cc. of a diffusion of an alcohol 



tate from a water extract of dehydrated Vlv 

 per cent toluene was added as an antiseptic 



lactuca. Two 

 and the flasks 



maintained at a temperature of 35 °C. for 30 days. The re- 

 sults of the experiments are given in table n. 



The data show but slight differences in the rate of digestion 

 of the starches with the exception of corn starch, and the 

 reason for this is not clear. One would expect it to be due to 

 some impurity in the starch rather than to an inherent dif- 

 ference in the granule. The action on inulin was so slight as 

 not to warrant the assumption of hydrolysis due to inulase. 



The action of an extract of Viva lactuca upon various carbo- 

 hydrates.— A series was arranged using a "diffusion- 

 extract" from Viva lactuca with the following substrates: 

 potato starch, dextrin, glycogen, sucrose, maltose, and lactose. 

 Ten cc. of the " diffusion-extract' ' were added to each flask 

 with 50 cc. of substrate, 2 per cent toluene used as an anti- 

 septic, and the flasks maintained at a temperature of 35 °C. 

 for 30 days. The data are given in table in. 



TABLE III 



EXTRACT 



Substrate 



Starch . . 



Dextrin . 

 Glycogen 

 Sucrose. 

 Lactose . 



Maltose . 



Sugar as glucose in 5 cc. 



ragms. 



15 days 



30 days 



10.20 

 6.30 

 2.25 





15.50 

 9.95 

 3.50 



Trace 



Trace 



The two polysaccharides, starch and dextrin, are very 

 readily attacked even though the action is slow. Glycogen, 

 which is hydrolysed by most diastatic enzymes with about the 



