1915] 



DAVIS — ENZYME ACTION IN MARINE ALGAE 773 



nucleate with an unstated amount of crushed seaweed. The 

 temperature during the incubation period varied from 21 

 to 26° C. for the different forms used. The following are his 

 results for 100 cc. of substrate : 



TABLE I 



Alga 



Cladophora frusta 

 Ceramium rubrum 

 Griffithsia setaeea. 

 Phormidium sp. . . . 



Phosphorus as P2O5 



mgms. 



54.3 

 76.6 

 62.5 

 90.0 



Zaleski crushed growing tips of Vicia faba, added water 

 and an antiseptic, and allowed this material to autolyse at 

 34° C. for 4 days. At the end of that time the control flask 

 showed a free phosphorus content of 13.6 milligrams and the 

 one containing the active enzyme 51.2 milligrams. We have 

 no means of knowing even the relative amount of enzyme 

 present in any of these experiments and yet it seems that the 

 algal nuclease compares very favorably with that isolated 

 from the fungi and the higher plants. 



The classes in plant physiology at the Marine Biological 

 Laboratory, Woods Hole, for several years past have quali- 

 tatively determined diastase in Viva lactuca. Bartholemew 

 ('14), working on the question of starch in the Florideae, 

 conclusively demonstrated diastase present in such " reds" 

 as Polysiphonia variegata, Dasya elegans, Agardhiella tenera, 

 and Ceramium sp. In order to isolate the enzyme, he used 

 the ordinary method of precipitation by alcohol from an 

 aqueous extract of crushed tissue. Starch as paste was 

 hydrolysed rather slowly to an undetermined reducing sugar, 

 presumably dextrose, 5 cc. of .25 per cent starch paste with 

 a relatively large amount of the enzyme material requiring 

 from 6 to 9 days for the completion of hydrolysis. Micro- 

 scopic observation of the attacked starch grain showed corro- 

 sion similar to that caused by the translocation diastase of 

 the barley. Torup (Krefting and Torup, '09) had previously 

 isolated an enzyme from fresh Laminaria that hydrolysed the 

 characteristic storage carbohydrate of that alga, laminarin, 

 to dextrose. 



