Search results for "Yarrowia"
showing 10 items of 44 documents
Characterization of a disulphide-bound Pir-cell wall protein (Pir-CWP) ofYarrowia lipolytica
2003
In this work we have studied the disulphide-bound group of cell wall mannoproteins of Yarrowia lipolytica and Candida albicans. In the case of Y. lipolytica, SDS-PAGE analysis of the beta-mercaptoethanol-extracted material from the purified cell walls of the yeast form, showed the presence of a main polypeptide of 45 kDa and some minor bands in the 100-200 kDa range. This pattern of bands is similar to that obtained in identical extracts in Saccharomyces cerevisiae (Moukadiri et al., 1999), and besides, all these bands cross-react with an antibody raised against beta-mercaptoethanol-extracted material from the purified cell walls of S. cerevisiae, suggesting that the 45 kDa band could be th…
Secondary structure conformation of hydroperoxide lyase from green bell pepper, cloned in Yarrowia lipolytica, and its activity in selected media
2008
International audience; Circular dichroism (CD) spectroscopy of secondary structure conformation of the purified green bell pepper hydroperoxide lyase (HPL), cloned in the yeast Yarrowia lipolytica, was investigated. The CD spectra of HPL in iso-octane, obtained at 60 °C, in the presence of the reducing agent dithiothreitol showed dramatic increase in α-helix content. The enzyme conformation remained unchanged over a range of pH values of 5.0–7.0. Using 13-hydroperoxide of linoleic acid (13-HPOD) as substrate, the biocatalysis of HPL in organic solvent media, including chloroform, dichloromethane, hexane, iso-octane, octane and toluene, was investigated. The results indicated an increase in…
Cloning and characterization of the peroxisomal acyl CoA oxidaseACO3 gene from the alkane-utilizing yeastYarrowia lipolytica
1998
The ACO3 gene, which encodes one of the acyl-CoA oxidase isoenzymes, was isolated from the alkane-utilizing yeast Yarrowia lipolytica as a 10 kb genomic fragment. It was sequenced and found to encode a 701-amino acid protein very similar to other ACOs, 67.5% identical to Y. lipolytica Aco1p and about 40% identical to S. cerevisiae Pox1p. Haploid strains with a disrupted allele were able to grow on fatty acids. The levels of acyl-CoA oxidase activity in the ACO3 deleted strain, in an ACO1 deleted strain and in the wild-type strain, suggested that ACO3 encodes a short chain acyl-CoA oxidase isoenzyme. This narrow substrate spectrum was confirmed by expression of Aco3p in E. coli.
Intracellular pH-dependent efflux of the fluorescent probe pyranine in the yeast Yarrowia lipolytica.
2001
International audience; 8-Hydroxypyrene-1,3,6-trisulfonic acid (pyranine) can be used as a vital intracellular pH (pH(i)) indicator. In the yeast Yarrowia lipolytica, a partial efflux of the probe was detected by using the pH-independent wavelength of 415 nm. A simplified correction of the fluorescent signals was applied, enabling to show for this species a good near-neutral pH(i) maintenance capacity in a pH 3.9 medium. Octanoic acid, which is known to have toxic effects on yeast, decreased the pH(i) and increased the 260-nm-absorbing compounds leakage. However, this acid inhibited the fluorescent probe efflux linearly with its concentration suggesting a pH(i)-dependent efflux of pyranine …
RHO1(YlRHO1) is a non-essential gene inYarrowia lipolyticaand complementsrho1Δlethality inSaccharomyces cerevisiae
2003
The synthesis of beta-1,3-glucan, the structural component of the yeast cell wall that gives shape to the cell, occurs at the plasma membrane and is the result of the activity of at least a two-component complex. Fks1p is the catalytic subunit directly responsible for the synthesis of beta-1,3-glucan, whilst the second subunit, Rho1p, has a GTP-dependent regulatory role (Yamochi et al., 1994). RHO1 has been characterized in Saccharomyces cerevisiae (Yamochi et al., 1994), and in several other fungal species. In this work, we have used degenerate oligonucleotides derived from the conserved regions of Rho1ps to isolate the RHO1 gene of Yarrowia lipolytica. The gene isolated in this way, which…
Isolation of theMNN9gene ofYarrowia lipolytica(YlMNN9) and phenotype analysis of a mutantylmnn9Δ strain
2003
In this work we describe the isolation of the Yarrowia lipolytica homologue of Saccharomyces cerevisiae MNN9 gene, which we have named YlMNN9, and the phenotype analysis of a Y. lipolytica strain containing the disrupted YlMNN9 allele. YlMNN9 was cloned using degenerate consensus oligonucleotides to generate specific probes that were in turn used to screen mini-gene libraries. The gene is defined by a 1014 bp ORF predicted to encode a protein 337 amino acids long that shares significant homology with the Mnn9ps of S. cerevisiae, Candida albicans and Hansenula polymorpha, including a putative N-terminal transmembrane domain. Disruption of YlMNN9 leads to phenotypes such as resistance to sodi…
Expression ofYWP1,a Gene That Encodes a SpecificYarrowia lipolyticaMycelial Cell Wall Protein, inSaccharomyces cerevisiae
1997
Abstract The YWP1 gene encoding a specific mycelial cell wall protein of Yarrowia lipolytica has been cloned and expressed in Saccharomyces cerevisiae using different episomal plasmids. Because the plasmids pYAE35BB and pYAE35ES carrying the YWP1 gene (including the 5′ noncoding promoter sequences) failed to express it, the YWP1 gene was cloned under the control of GAL/CYC or ACT S. cerevisiae promoters. A main band with an apparent molecular mass of 70 kDa was detected by immunoblotting in the cell wall fraction of transformants. Ywp1 processing and incorporation to the cell wall were similar in both Y. lipolytica and S. cerevisiae but not in its final localization in the cell wall. In Y. …
Different effectors of dimorphism in Yarrowia lipolytica
2002
Yarrowia lipolytica is an ascomycete with biotechnological potential. In common media, the fungus grows as a mixture of yeast-like and short mycelial cells. The environmental factors that affect dimorphism in the wild-type strain, W29, and its auxotrophic derivative, PO1a, were analyzed. In both strains, pH was the most important factor regulating the dimorphic transition. Mycelium formation was maximal at pH near neutrality and decreased as pH was lowered to become almost null at pH 3. Carbon and nitrogen sources, namely glucose and ammonium, were also important for mycelium formation; and their effect was antagonized by some alternative carbon and nitrogen sources. Citrate was an importan…
Traditional fermented sausage ‘Nem chua’ as a source of yeast biocatalysts efficient for the production of the aroma compound γ-decalactone
2013
International audience; The yeast ecosystem of Nem chua, a Vietnamese traditional fermented sausage naturally rich in medium‐chain‐length lipid‐derived flavouring compounds, was investigated to select biocatalysts able to produce the C10‐fatty acid‐derived aroma compound γ‐decalactone. The total number of yeast was about 5 × 104 to 4 × 105 CFU g−1, and eighty four different species were identified from morphological, physiological and 26S rDNA characteristics, with Candida sake and Candida haemulonii being found in all samples. Six strains able to produce γ‐decalactone from castor oil were selected, of which three Yarrowia lipolytica strains were able to produce between 1 and 2 g L−1 in our…
Evaluation of acyl coenzyme A oxidase (Aox) isozyme function in the n- alkane-assimilating yeast Yarrowia lipolytica
1999
ABSTRACT We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n -alkane-assimilating yeast Yarrowia lipolytica , encoded by the POX1 through POX5 genes. The physiological function of these oxidases has been investigated by gene disruption. Single, double, triple, and quadruple disruptants were constructed. Global Aox activity was determined as a function of time after induction and of substrate chain length. Single null mutations did not affect growth but affected the chain length preference of acyl-CoA oxidase activity, as evidenced by a chain length specificity for Aox2 and Aox3. Aox2 was shown to be a long-chain acyl-CoA oxidase and Aox3 was found to …