PLANKTON 35 



TABLE IV.— Amino Acid Assay of Dried Chlorella 



Pilot Plant Laboratory 



Nutrient Sample Sample Torula Yeast 



Crude protein 44.00% 40.0096 — 



Arginine 2.06 2.39 3.61% 



Histidine • 0.62 0.65 1.31 



Isoleucine 1.75 1.69 3.75 



Leucine 3.79 1.99 3.57 



Lysine 2.06 2.43 4.14 



Methionine 0.36 0.57 0.84 



Phenylalanine 1.81 2.14 2.41 



Threonine 2.12 1.91 2.58 



Tryptophane 0.80 0.41 0.66 



Valine 2.47 2.67 2.98 



Glycine — 2.20 0.22 



the amino acids from ammonia and the requisite carbon fractions, and they 

 must thus depend at least in part upon an exogenous source of some 

 amino acids. The deficiency is not of the amino acid per se, but of the 

 capacity to form amino groups from ammonia. Thus, for proper growth, 

 Euglena deses requires aspartic acid, while Chlamydomonas cblamydogama 

 needs histidine and aspartic acid. 40 



Nucleic acid has been demonstrated by staining reactions to be present 

 in algal cells. Jeener 216 reported that Polytomella caeca had 6 to 10 per 

 cent of its protein as ribonucleic acid in actively growing cells. He indi- 

 cated that there was great variability in the synthesis of nucleic acid, and 

 that this was unrelated to the rate of general protein synthesis and cellular 

 multiplication. Szafarz and Brachet 217 indicated that formation of ribo- 

 nucleic acid can proceed independently of the nucleus in Acetabularia 

 mediterranea. Studies by Goryunova 218 have indicated the presence of 

 mucins in Oscillatoria. 



The assimilation of nitrogen by algae is important not only with respect 

 to amino acids, but also in the synthesis of various carbon compounds. 

 As in the case of certain bacteria, many autotrophic algae are characteris- 

 tically capable of nitrogen fixation. Nitrogen may be absorbed as the 

 element, or as nitrate or ammonia. Frank, 219 in 1889, first reported the 

 possible nitrogen-fixing properties of certain algae, but this was not proven 

 until 1928. 220 Since then, further corroboration has come from Kjeldahl 

 determinations and tracer studies using nitrogen isotopes. 40 So far, over 

 20 species of Myxophyceae have been proven capable of fixing nitrogen. 

 Aspartic acid, glutamic acid, succinamide, asparagine, and glutamine can 



