title: Physiological and biochemical characteristics of the ethyl tiglate production pathway in the yeast Saprochaete suaveolens.
abstract: A yeast identified as Saprochaete suaveolens was investigated for its capacity to produce a large panel of flavouring molecules. With a production of 32 compounds including 28 esters, S. suaveolens seems to be a good producer of fruity flavours and fragrances and especially of unsaturated esters, such as ethyl tiglate. Physiological and biochemical analyses were performed in this study in an attempt to comprehend the metabolic route to the formation of this compound. We show that the accumulation of ethyl tiglate by S. suaveolens is specifically induced by isoleucine. However, and contrary to S. cerevisiae, which harbours a classical Ehrlich pathway leading to the production of 2-methylbutanol from isoleucine, our results provide phenotypic and enzymological evidence of ethyl tiglate biosynthesis in S. suaveolens through the catabolism of this amino acid by the β-oxidation pathway, which generates tiglyl-CoA as a probable intermediate. A kinetic analysis of this flavour molecule during growth of S. suaveolens on glucose and isoleucine showed a phase of production of ethyl tiglate that culminated concurrently with isoleucine exhaustion, followed by a disappearance of this compound, likely due to reassimilation by the yeast.
authors.affiliation: Université de La Réunion, Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Sainte Clotilde, La Réunion, France; Département Génie Biologique, IUT, Université de La Réunion, Saint Pierre, La Réunion, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Grondin
authors.forename: Alain
authors.initials: A
authors.lastname: Shum Cheong Sing
authors.forename: Yanis
authors.initials: Y
authors.lastname: Caro
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: de Billerbeck
authors.forename: Jean Marie
authors.initials: JM
authors.lastname: François
authors.forename: Thomas
authors.initials: T
authors.lastname: Petit
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D053898:Biosynthetic Pathways; D003437:Crotonates / Q000378:metabolism*; D004952:Esters / Q000378:metabolism*; D005421:Flavoring Agents / Q000378:metabolism*; D045782:Hemiterpenes; D007532:Isoleucine / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
chemical_list: D000214:Acyl Coenzyme A; D003437:Crotonates; D004952:Esters; D005421:Flavoring Agents; D045782:Hemiterpenes; D007532:Isoleucine; C033618:tiglyl-coenzyme A; C009489:tiglic acid
keywords: Ehrlich pathway; Saprochaete suaveolens; ascomycetes; esters; flavours and fragrances; β-oxidation