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

LIBKIND DIEGO; BRIZZIO SILVIA; DE GARCÍA VIRGINIA; VAN BROOCK MARÍA

BIOCELL

INST HISTOL EMBRIOL-CONICET

Año: 2003 vol. 27 p. 80 - 80

0327-9545

The red yeast Rhodotorula mucilaginosa strain CRUB 0138 (previously identified as Rh. lactosa), was isolated from a high altitude Patagonian lake (Toncek, 1700 m.a.s.l.), and assigned to mucilaginosa species. Its biochemical, physiological and molecular features were assessed and compared to Rh. mucilaginosa PYCC 5166 type strain under a polyphasic approach. In addition, biomass and carotenoid pigment (CP) production using different C/N ratios were studied in an incubator shaker. Phenetic characterization by means of 70 current physiological tests including assimilation of aldaric acids and aromatic compounds, and also the ability to grow with aminoacids as sole carbon sources, were carried out. Molecular analysis was based on Mini/Micro Satellite Primed PCR technique (MSP-PCR) employing (GTG)5, M13 and (GAC)5 primers. According to numeric taxonomy calculations, similarity indexes between Rh. mucilaginosa CRUB 0138 and Rh. mucilaginosa PYCC 5166 type strain were 0.86 and 0.77 corresponding to complete set of physiological tests and MS-PCR fingerprinting respectively. Killer activity against two native strains, Rhodosporidium kratochvilovae and Rh. mucilaginosa was detected. Maximum biomass-glucose conversion efficiency (87%) and maximum carotenoid yield (2,32 mg L-1) were obtained at C/N 5 in culture medium containing glucose 10 and 40 g L-1 respectively. Different C/N ratios did not influence carotenoid pigment production but low C/N enhanced biomass yield.