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Biomedical subjects

L Dulau

Publications and source records attributed to L Dulau.

5 recordsLinked to original sources
PubMed1997

Metabolic analysis of S. cerevisiae strains engineered for malolactic fermentation.

A complete malolactic fermentation was achieved using Saccharomyces cerevisiae strains coexpressing the genes mleS and mae1 coding for the Lactococcus lactis malolactic enzyme and the Schizosaccharomyces pombe malate permease under the control of yeast promoters. The expression level of mae1 greatly influences the kinetics of the reaction by controlling the rate of malate uptake meanwhile a high expression level of mleS induces a partial consumption of malate derived from glucose by the malolactic enzyme. A strain expressing several copies of mae1 and one copy of mleS degrades 3 g/l of malate almost exclusively through the malolactic pathway in 4 days under enological conditions, without metabolic side effects.

Bacterial Proteins↗
PubMed1995

Genetic diversity and geographical distribution of wild Saccharomyces cerevisiae strains from the wine-producing area of Charentes, France.

Electrophoretic karyotyping, mitochondrial DNA restriction fragment length polymorphism analysis, and PCR amplification of interspersed repeats were used to study the variability, phylogenetic affinities, and biogeographic distribution of wild Saccharomyces cerevisiae enological yeasts. The survey concentrated on 42 individual wine cellars in the Charentes area (Cognac region, France). A limited number (35) of predominant S. cerevisiae strains responsible for the fermentation process have been identified by the above molecular methods of differentiation. One strain (ACI) was found to be distributed over the entire area surveyed. There seemed to be little correlation between geographic location and genetic affinity.

DNA, Fungal↗
PubMed1991

Yeast mutant affected for viability upon nutrient starvation: characterization and cloning of the RVS161 gene.

In yeast, nutrient starvation leads to entry into stationary phase. Mutants that do not respond properly to starvation conditions have been isolated in Saccharomyces cerevisiae. Among them the rvs161 mutant (RVS for Reduced Viability upon Starvation) is sensitive to carbon, nitrogen and sulphur starvation. When these nutrients are depleted in the medium, mutant cells show cellular viability loss with morphological changes. The mutation rvs161-1 is very pleiotropic, and besides the defects in stationary phase entry, the mutant strain presents other alterations: sensitivity to high salt concentrations, hypersensitivity to amino acid analogs, no growth on lactate or acetate medium. The addition of salts or amino acid analogs leads to the same morphological defects observed in starved cells, suggesting that the gene could be implicated mainly in the control of cellular viability. The gene RVS161 was cloned; it codes for a 30,252 daltons protein. No homology was detected with the proteins contained in the databases. Moreover, Southern analysis revealed the presence of other sequences homologous to the RVS161 gene in the yeast genome.

Amino Acid Sequence↗