Community analysis of pigment patterns from 37 microalgae strains reveals new carotenoids and porphyrins characteristic of distinct strains and taxonomic groups

Phytoplankton, with an estimated 30 000 to 1 000 000 species clustered in 12 phyla, presents a high taxonomic and ecophysiological diversity, reflected by the complex distribution of pigments among the different algal classes. High performance liquid chromatography is the gold standard method for qualitative and quantitative analysis of phytoplankton pigments in seawater and culture samples, but only a few pigments can be used as robust chemotaxonomic markers. A major challenge is thus to identify new ones, characteristic of a strain, species, class or taxon that cannot be currently identified on the basis of its pigment signature. Using an optimized extraction process coupled to a HPLC de-replication strategy, we examined the pigment composition of 37 microalgae strains, representative of the broad taxonomic diversity of marine and freshwater species (excluding cyanobacteria). For each species, the major pigments already described were unambiguously identified. We also observed the presence of several minor unidentified pigments in each chromatogram. The global analysis of pigment compositions revealed a total of 124 pigments, including 98 pigments or derivatives unidentified using the standards. Absorption spectra indicated that 35 corresponded to chlorophyll/porphyrin derivatives, 57 to carotenoids and six to derivatives having both spectral signatures. Sixty-one of these unidentified or new carotenoids and porphyrin derivatives were characteristic of particular strains or species, indicating their possible use as highly specific chemotaxonomic markers capable of identifying one strain out of the 37 selected. We developed a graphical analysis using Gephi software to give a clear representation of pigment communities among the various phytoplankton strains, and to reveal strain-characteristic and shared pigments. This made it possible to reconstruct the taxonomic evolution of microalgae classes, on the basis of the conservation, loss, and/or appearance of pigments.

Full Text

FilePagesSizeAccess
Publisher's official version
353 Mo
S1 Fig. A) Calculation of carotenoid band ratio. B) Calculation of porphyrin band ratio
1171 Ko
S2 Fig. Chromatograms at 436 nm of all carotenoid and chlorophyll pigments detected in the 37 analysed strains.
191 Mo
S3 Fig. Spectra of unidentified pigments.
501 Mo
S1 Table. Pigments and derivatives used as chemotaxonomic markers of phytoplankton strains, species, and classes.
2116 Ko
S1 Dataset. Gephi community
-34 Ko
How to cite
Serive Benoit, Nicolau Elodie, Berard Jean-Baptiste, Kaas Raymond, Pasquet Virginie, Picot Laurent, Cadoret Jean-Paul (2017). Community analysis of pigment patterns from 37 microalgae strains reveals new carotenoids and porphyrins characteristic of distinct strains and taxonomic groups. Plos One. 12 (2). e0171872 (1-35). https://doi.org/10.1371/journal.pone.0171872, https://archimer.ifremer.fr/doc/00373/48416/

Copy this text