INVESTIGADORES
DIEGUEZ Maria Del Carmen
artículos
Título:
Mycosporines from freshwater yeasts: a trophic cul-de-sac?.
Autor/es:
PÉREZ,P., LIBKIND,D., DIÉGUEZ, M.C. SUMMERER, M., SONNTAG, SOMARUGA, R., B., VAN BROOK, M AND H. E. ZAGARESE.
Revista:
Photochemical and Photobiological Sciences
Editorial:
The Royal Society of Chemistry and owner societies
Referencias:
Año: 2006 vol. 5 p. 25 - 30
ISSN:
1474-905X
Resumen:
Mycosporine-like amino-acids (MAAs) are found in aquatic bacteria, algae, and animals. A related
compound, the mycosporine-glutaminol-glucoside (myc-glu-glu), has recently been reported in
freshwater yeasts. Although animals depend on other organisms as their source of MAAs, they can
efficiently accumulate them in their tissues. In this work we assessed the potential transfer of the yeast
mycosporine myc-glu-glu from the diet into the copepod Boeckella antiqua and the ciliate Paramecium
bursaria. For this purpose, we performed experiments to study the feeding of B. antiqua and P. bursaria
on the yeast Rhodotorula minuta and their ability to bioaccumulate myc-glu-glu. Bioaccumulation of
myc-glu-glu in B. antiqua was assessed through long-term factorial experiments manipulating the diet
(Chlamydomonas reinhardii and C. reinhardii + yeasts) and radiation exposure (PAR and PAR + UVR).
Shorter term experiments were designed in the case of P. bursaria. The composition and concentration
of MAAs in the diet and in the consumers were determined by HPLC analyses. Our results showed that
even though both consumers ingested yeast cells, they were unable to accumulate myc-glu-glu.
Moreover, when exposed to conditions that stimulated the accumulation of photoprotective
compounds (i.e. UVR exposure), an increase in MAAs concentration occurred in copepods fed C.
reinhardii plus yeasts as well as in those fed only C. reinhardii. This suggests that the copepods were able
to modify their tissue concentrations of MAAs in response to environmental clues but also that the
contribution of yeast mycosporines to total MAAs concentration was negligible.