Studies on carotenoid pigment production by Rhodotorula mucilaginosa CRUB0138. Effect of C/N ratio

LIBKIND FRATI, D; BRIZZIO, S; DE GARCÍA, V; VAN BROOCK, MR

Bariloche, Arg

Congreso; XXXIX Reunión Anual de SAIB; 2003

The carotenoid pigments (b-carotene, torulene, etc.) produced by certain yeast species possess potential biotechnological aplications in the cosmetic, farmaceutic and alimentary industries. The Rhodotorula mucilaginosa yeast strain CRUB0138 isolated from a northwestern patagonia high altitud lake (1700 m.a.s.l.) was shown to be a good biomass and carotenoid pigment producer at lab scale using semi-synthetic media at low glucose concentrations (1%). Here we studied the behavior of this strain employing higher glucose concentrations (4%) and the effect of different C/N (5, 20 and 100) ratios on biomass and carotenoid pigments yields. Assays were carried out in an incubator shaker INNOVA 4000. Analytical measurements consisted in dry weight, remaining glucose, pH and carotenoid content. The extraction of the pigments was achieved using the DMSO method and their were quantitatively and qualitatively analyzed through spectrophotometer and TLC based tests. High biomass volumetric productivity was obtained using low C/N ratios (5), however, carotenoid pigment yields nor their composition were significantly altered by the different C/N ratios tested. A maximum of carotenoid pigments was achieved (2,32 mg L-1) at 96 hs of culture using a C/N of 5 and 4 % of glucose.