Journal of
Yeast and Fungal Research

  • Abbreviation: J. Yeast Fungal Res.
  • Language: English
  • ISSN: 2141-2413
  • DOI: 10.5897/JYFR
  • Start Year: 2010
  • Published Articles: 125

Full Length Research Paper

Molecular cloning and characterization of STL1 gene of Debaryomyces hansenii

Juan Carlos González-Hernández
Laboratorio de Bioquímica del Departamento de Ingeniería Bioquímica, Instituto Tecnológico de Morelia; Avenida Tecnológico 1500. C. P. 58120. Morelia, Michoacán, México.
Email: [email protected]

  •  Accepted: 26 April 2010
  •  Published: 30 June 2010

Abstract

Debaryomyces hansenii is often found in salty environments. This yeast species is not only halotolerant, but also halophilic. Its genome sequence is known completely, but the mechanisms behind its halotolerance are poorly understood. It was compared to the STL1 protein sequence of Saccharomyces cerevisiaeagainst the translated sequence from the D. hansenii genome sequence database released by Génolevure. An ORF (DEHA0E01122g) was found with 54% homology and 39% identity with Stl1p from S. cerevisiaeDhSTL1 was heterologously expressed successfully in a S. cerevisiae (BY4741) wild type and in another strain lacking its own system for the glycerol transport (STL1) gene. The DhSTL1 gene in transformed S. cerevisiae strains showed a slight but significant difference in the doubling times in growth curves obtained in liquid YNB-ura medium, with glycerol as carbon source. DhSTL1 gene in transformed stl1 yeast strain showed phenotype growth at pH 7.5 under salt stress conditions (glucose as carbon source). The kinetic parameters of transport and glycerol accumulation conferred by DhSTL1 in the S. cerevisiae transformant strains did not show significant differences. An increase in the transcript level of DhSTL1 gene in the presence of saline stress at pH 5.6; whereas, at 7.5 pH, it was expressed in all evaluated conditions.

 

 Key wordsDebaryomyces hansenii, glycerol, transport, salt tolerance.