Abstract

GUAMAN-BURNEO, Cristina  and  CARVAJAL-BARRIGA, Javier. Characterization and identification of isolates of carotenogenic yeast strains from several natural zones of Ecuador. Univ. Sci. [online]. 2009, vol.14, n.3, pp.187-197. ISSN 0122-7483.

Objective. To identify and characterize pigmented yeasts isolated from natural environments in Ecuador, producing metabolites with industrial importance and with potential use in further biotechnological applications. Materials and methods. Twenty-six pigmented isolates from the "Colección de Levaduras Quito-Católica" (CLQCA) were exposed to physiological and molecular tests for their characterization, typification and identification. Sugar assimilation ability was evaluated. Molecular techniques such as ITS-RFLP, MSP-PCR, partial amplification of the segment 26S of the rDNA, and sequencing were used for their identification at the species level. Growth curves for each isolate according to their specific optimum growth temperatures. Results. The following species were identified: Rhodotorula mucilaginosa, Rhodosporidium babjevae, Sporidiobolus ruineniae, Rhodotorula glutinis, Rhodotorula slooffiae, as well as a new species of the genus Rhodotorula. Conclusions. Rhodotorula mucilaginosa (CLQCA-12-013 and CLQCA-12-008) and Rhodosporidium babjevae (CLQCA-10-188) isolates were selected as promising strains for industrial applications, because they showed characteristics such as rapid growth, high assimilation of sugars, biomass production, and pigment synthesis.

Keywords : pigmented yeasts; molecular and physiological typification; growth curve.

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