Carotenoids pigments enhance photoprotection in the yeast Rhodotorula mucilaginosa.

MOLINÉ, MARTÍN; LIBKIND, DIEGO; DIÉGUEZ, MARÍA DEL CARMEN; GIRAUDO, MARÍA ROSA

Pinamar, Argentina

Congreso; 41º Reunion anual de de sociedad Bioquímica y Biología molecular; 2005

SAIB

We analyze the relationship between carotenoid pigments and UV-B resistance in strains of the yeast Rh. mucilaginosa.  Carotenoid and phytoene (a carotenoid precursor) production as well as the cell survival to UV-B exposure were studied using a set of 13 strains both type strain and Patagonian native isolates. Albino and hyper pigmented mutants of one selected strain were obtained after UV-B mutagenesis and characterized by molecular (PCR-fingerprinting) and conventional techniques. These strains were studied as described above and compared with T type. Data from the first screening were submitted to principal component analysis showing a strong relationship between total carotenoids concentration and UV-B survival, while phytoene concentration did not co-relate with these two variables (carotenoids and resistance). In the second assay the albino mutant presented similar UV-B survivorship than the parental strain while the hyper pigmented (300% increase in total carotenoid) showed a consistent upgraded survival (250%). These results support the idea that enhanced carotenoid concentration in pigmented yeasts could be responsible for survivorship and play a role as UV-B resistance mechanism.