title: L-Arabinose transport and catabolism in yeast.
abstract: Two yeasts, Candida arabinofermentans PYCC 5603(T) and Pichia guilliermondii PYCC 3012, which show rapid growth on L-arabinose and very high rates of L-arabinose uptake on screening, were selected for characterization of L-arabinose transport and the first steps of intracellular L-arabinose metabolism. The kinetics of L-arabinose uptake revealed at least two transport systems with distinct substrate affinities, specificities, functional mechanisms and regulatory properties. The L-arabinose catabolic pathway proposed for filamentous fungi also seems to operate in the yeasts studied. The kinetic parameters of the initial L-arabinose-metabolizing enzymes were determined. Reductases were found to be mostly NADPH-dependent, whereas NAD was the preferred cofactor of dehydrogenases. The differences found between the two yeasts agree with the higher efficiency of L-arabinose metabolism in C. arabinofermentans. This is the first full account of the initial steps of L-arabinose catabolism in yeast including the biochemical characterization of a specific L-arabinose transporter.
authors.affiliation:  Centro de Recursos Microbiológicos (CREM), Biotechnology Unit, Faculty of Sciences and Technology, New University of Lisbon, Caparica, Portugal Department of Applied Microbiology, Lund University, Sweden.
authors.forename: César
authors.initials: C
authors.lastname: Fonseca
authors.affiliation:  Centro de Recursos Microbiológicos (CREM), Biotechnology Unit, Faculty of Sciences and Technology, New University of Lisbon, Caparica, Portugal Department of Applied Microbiology, Lund University, Sweden.
authors.forename: Rute
authors.initials: R
authors.lastname: Romão
authors.affiliation:  Centro de Recursos Microbiológicos (CREM), Biotechnology Unit, Faculty of Sciences and Technology, New University of Lisbon, Caparica, Portugal Department of Applied Microbiology, Lund University, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Rodrigues de Sousa
authors.affiliation:  Centro de Recursos Microbiológicos (CREM), Biotechnology Unit, Faculty of Sciences and Technology, New University of Lisbon, Caparica, Portugal Department of Applied Microbiology, Lund University, Sweden.
authors.forename: Bärbel
authors.initials: B
authors.lastname: Hahn-Hägerdal
authors.affiliation:  Centro de Recursos Microbiológicos (CREM), Biotechnology Unit, Faculty of Sciences and Technology, New University of Lisbon, Caparica, Portugal Department of Applied Microbiology, Lund University, Sweden.
authors.forename: Isabel
authors.initials: I
authors.lastname: Spencer-Martins
mesh_terms: D027321:Anion Transport Proteins / Q000378:metabolism; D001089:Arabinose / Q000378:metabolism*; D002175:Candida / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D010843:Pichia / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism
chemical_list: D027321:Anion Transport Proteins; D014994:Xylose; D001089:Arabinose; D005947:Glucose