1915] 



DAVIS ENZYME ACTION IN MARINE ALGAE 



823 



"B" would be almost negligible were the findings not so con- 

 sistent. There is a definiteness about the increase over the 

 checks that can hardly be ignored. In order to get further 

 evidence on this point, however, another series (table xvn) 

 was set up, using urea and asparagin in 1 per cent concentra- 

 tions as substrates. The flasks were maintained at a tempera- 



ture of 35°C. for 30 days. 



TABLE XVII 



THE ACTION OF DEHYDRATED CHLAMYDOMONAS CELLS UPON ASPARAGIN 



AND UREA 



Substrate 



Weight 



algal 

 powder 



Nitrogen as NH 3 split 



off in 30 days 



mgms. 



Net nitrogen 

 mgms. 



Asparagin 



.5 grams "A" 

 .5 grams "B" 



1.15 



3.10 



.65 



.20 

 2.20 









Urea 



.5 grams "A" 

 .5 grams "B" 



1.45 

 3.70 



.98 



.17 

 2.47 









Water 



.5 grams "A" 

 .5 grams "B" 



.30 1 



.25 | 









In this, as in table xvi, the evidence goes to show that al- 

 though the desamidization is practically negligible where the 

 alga is grown with (NH3) 2 S04 as a source of nitrogen, it is 

 definite where the nitrogen is supplied in the amino and amido 

 form. The actual splitting is small in any case. 



On the basis of the above, we can simply reason by analogy, 

 and yet this analogy points to the fact that the probable 

 reason for the failure to demonstrate amidase in Viva lies 

 in the failure to form that enzyme. This in turn would indi- 

 cate that the great growth of Viva in sewage-contaminated 

 waters is probably due to the abundance of desamidizing bac- 

 teria which those waters maintain — bacteria which break 

 down the protein molecule with the ultimate setting free of 



!. Nitrogen, as such, becomes directly available to the 



NH 3 . 

 plant. 



NUCLEASES 



The presence of nucleases in the algae has already been 

 reported by Teodoresco ('12), but since he investigated only 



