INVESTIGADORES
ZAGARESE Horacio Ernesto
artículos
Título:
Occurrence of Photoprotective Compounds in Yeasts from Freshwater Ecosystems of Northwestern Patagonia
Autor/es:
DIEGO LIBKIND,; DEL CARMEN DIÉGUEZ, MARÍA; MOLINÉ; PATRICIA PÉREZ,; HORACIO ZAGARESE; VAN BROOCK, MARÍA
Revista:
PHOTOCHEMISTRY AND PHOTOBIOLOGY
Referencias:
Año: 2006 vol. 82 p. 972 - 980
ISSN:
0031-8655
Resumen:
In this paper we present the results of
research on the occurrence, induction and role of photoprotective compounds
(PPCs) present in native aquatic yeasts from freshwater Patagonian ecosystems.
We focus on the effect of UV radiation (UVR) as a factor that controls the
level of photoprotection of yeasts, and explore its potential significance in
shaping yeast distributional patterns. The research presented here combines
field surveys and laboratory work, including the isolation and culture of
native yeasts strains, and laboratory assays under different radiation
conditions. The results obtained suggest that yeasts are common dwellers of
oligotrophic Patagonian water bodies, and provide the first evidence of the
distribution of PPC (carotenoid and mycosporine)producing yeasts in temperate
freshwaters. A greater proportion of carotenogenic yeasts were observed in
high-elevation lakes. The yeast strains isolated from these environments were
found to produce higher amounts of mycosporines (MYCs), and to present higher
tolerance to UVB exposure than those from piedmont lakes. Patagonian yeasts
have only one type of MYC, mycosporine-glutaminol-glucoside (myc-glu-glu),
which seems common to all other yeasts. By analyzing the production of
myc-glu-glu in a large number of yeasts belonging to different taxonomic groups,
we propose that this compound may have potential use as a chemotaxonomic marker
in yeast systematics. Collectively, our work reveals that in Patagonian
freshwater yeasts there is an apparent relation- ship between the ability to
produce PPCs, their tolerance to UV exposure and their success in colonizing
habitats highly exposed to UVR.