Distributions, biosyntheses and functions of carotenoids in algae

Abstract

Phototrophic organisms including algae necessarily synthesize both chlorophylls and carotenoids for photosynthesis. Many kinds of carotenoids are found in algae, and the new taxonomic technologies have been developed for the phylogenetics of the algae. In this review, relationship of the distribution of carotenoids and the phylogeny of oxygenic phototrophs in sea and fresh water, including cyanobacteria, red algae, brown algae and green algae, is summarized. These phototrophs contain division- or class-specific carotenoids, such as fucoxanthin, peridinin and siphonaxanthin. In addition, carotenogenesis pathways are discussed based on the chemical structures of carotenoids and known characteristics of carotenogenesis enzymes in other organisms; genes and enzymes for carotenogenesis in algae are not yet known. Most carotenoids bind to membrane-bound pigment-protein complexes, such as reaction center, light-harvesting and cytochrome b6f complexes. Some functions of carotenoids in photosynthesis are briefly summarized.