PLANKTON 



31 



Siphonein 



Siphonoxanthin 



Fucoxanthin 



Neofucoxanthin 



Diatoxanthin 



Diadinoxanthin 



Dinoxanthin 



Neodinoxanthin 



Peridinin 



Myxoxanthin 



Myxoxanthophyll 



Key Pigments in Algal Photosynthesis 



CHLOROPHYLLS 

 Types a, b, c, d, e 



CAROTENOIDS 



Carotenes 



Types a > 0> c 



Xanthophylls 

 Lutein 

 Zeaxanthin 

 Violaxanthin 

 Flavoxanthin 

 Neoxanthin 



PHYCOBILINS 



r and c Phycoerythrins 

 r and c Phycocyanins 



The distribution of these pigments in algae is rather variable. The 

 commonest chlorophyll is the type a, just as in higher plants. Chlorophyll 

 b, also present in higher plants, occurs only in the Chlorophyceae and the 

 Euglenineae. The other classes contain chlorophylls c, d, and e. Of the 

 carotenes, the /?-type is most abundant. The «-carotene, typical Chloro- 

 phyceae and the higher plants, is not found in some algae. In Bacillariophy- 

 ceae, for example, it is supplanted by e-carotene. Each algal class also 

 has its own characteristic xanthophyll, as may be deduced from the num- 

 ber that have been identified. Phycobilins, on the other hand, occur only 

 in the Rhodophyceae and the Myxophyceae, the former containing mostly 

 phycoerythrin, the latter phycocyanin ; the origin of these related pigments 

 in either Rhodophyceae or Myxophyceae is indicated by the designation 

 r or c, respectively. 



Granick and his associates reported 199 - 200 in 1953 on the protopor- 

 phyrin precursors produced by Chlorella mutants. They have been par- 

 ticularly interested in the relationship between chlorophyll and hemin, 

 seeking information on porphyria and blood formation in human beings. 

 Delia Rosa, 201 using C 14 , demonstrated that Chlorella vulgaris was able to 

 synthesize chlorophyll from acetate and glycine ; he also showed that chlo- 

 rophylls a and b are not interconvertible. Jorgensen 41 in Venezuela demon- 

 strated to one of us (M.S.) the red blood wiggler Chironomus growing 

 on the sides of his Chlorella culture containers; he suggested that there 

 might here be a conversion of chlorophyll to heme. French and Young 202 

 indicated that phycocyanin may be an intermediate in the resonance 

 transfer of energy from phycoerythrin to chlorophyll. 



