Differences in pigment composition and concentration between phototrophic, mixotrophic, and heterotrophic Chrysophyceae

The presence of distinct pigments is characteristic of different algal groups while the relative concentration of these pigments may vary with light conditions. Here we investigate the pigment pattern of 35 strains of Chrysophyceae by means of high-performance liquid chromatography. We further investigated shifts in pigment concentrations between light and dark conditions and the conservation of these pigment patterns in heterotrophic, mixotrophic, and phototrophic taxa. We did not find chlorophyll in heterotrophic strains but carotenoids were present in all taxa. In phototrophs and mixotrophs, we confirm the presence of the chlorophylls-a, c1, and c2 as well as of fucoxanthin. We provide evidence for the violaxanthin cycle as the dominant xanthophyll cycle. Moreover, we found pigments of the diadinoxanthin cycle in low concentrations. While pigment concentrations were regulated depending on light availability in photosynthetic taxa, they were unaffected by light in heterotrophic taxa.