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Ecosystème fromager : de l'étude du métabolisme du soufre chez Kluyveromyces lactis et Yarrowia lipolytica à l'interaction entre Kluyveromyces lactis et Brevibacterium aurantiacum

Abstract : Sulphur metabolism, which has a central role in the cell, is also important during the manufacturing of smear ripened cheeses. The cheese ecosystem degrades sulphur amino acids, producing volatile sulphur compounds (VSCs) indispensable for the flavour of these products. We studied sulphur metabolism in two cheese-ripening microorganisms, the hemiascomycetous yeasts Kluyveromyces lactis and Yarrowia lipolytica. The in silico analysis of the phylum of hemiascomycetes gave us for the first time an evolutionary vision of this metabolism. We found fundamental differences at the level of cysteine synthesis, but also at the level of the enzymes involved in the production of VSCs. This analysis constitutes a solid basis for the study of sulphur metabolism. Thus, we combined several exploratory approaches (transcriptome, metabolome, VSCs measurement) to have a global vision of this metabolism in K. lactis and Y. lipolytica. Major differences are observed in particular at the level of cysteine and taurine biosynthesis pathways. VSCs production seems to be connected to the surexpression of species-specific transaminases combined with the accumulation of intracellular methionine. Cheese ripening being dependent on a whole ecosystem, we also studied the interaction between two cheese-ripening microorganisms, K. lactis and Brevibacterium aurantiacum, by a transcriptomic approach comparing the genes expression of a co-culture to that of the pure cultures. We observed profound metabolic modifications especially with respect to carbon and biotin metabolisms.
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https://pastel.archives-ouvertes.fr/pastel-00548146
Contributor : Agnès Hebert <>
Submitted on : Saturday, December 18, 2010 - 9:42:58 PM
Last modification on : Saturday, June 6, 2020 - 10:15:24 PM
Long-term archiving on: : Friday, December 2, 2016 - 4:41:11 PM

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  • HAL Id : pastel-00548146, version 1
  • PRODINRA : 246330

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Citation

Agnès Hebert. Ecosystème fromager : de l'étude du métabolisme du soufre chez Kluyveromyces lactis et Yarrowia lipolytica à l'interaction entre Kluyveromyces lactis et Brevibacterium aurantiacum. Génomique, Transcriptomique et Protéomique [q-bio.GN]. AgroParisTech, 2010. Français. ⟨NNT : 2010AGPT0057⟩. ⟨pastel-00548146⟩

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