title: Metabolic engineering of Saccharomyces cerevisiae for the production of 2-phenylethanol via Ehrlich pathway.
abstract: 2-Phenylethanol (2-PE), a fragrance compound with a rose-like odor, is widely used in perfumery and cosmetics. Here, we report the first metabolic engineering approach for 2-PE production in Saccharomyces cerevisiae. 2-PE can be produced from the catabolism of L-phenylalanine via Ehrlich pathway, consisting of transamination to phenylpyruvate by Aro9, decarboxylation to phenylacetaldehyde by Aro10, and reduction to 2-PE by alcohol dehydrogenases. We demonstrated that Ald3 is mainly responsible for phenylacetaldehyde oxidation, competing with 2-PE production. ALD3 deletion strain overexpressing ARO9 and ARO10 both by episomal overexpression and by induction of the endogenous genes through overexpression of Aro80 transcription factor, produced 4.8 g/L 2-PE in a medium containing 10 g/L L-phenylalanine as a sole nitrogen source. Considering the cytotoxicity of 2-PE, this production titer is almost the upper limit that can be reached in batch cultures, suggesting the great potential of this yeast strain for 2-PE production. 2-PE production was further increased by applying two-phase fermentation method with polypropylene glycol 1200 as an extractant, reaching 6.1 g/L 2-PE in organic phase with the molar yield of 82.5%, which is about ninefold increase compared with wild type.
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea.
authors.forename: Bosu
authors.initials: B
authors.lastname: Kim
authors.forename: Bo-Ram
authors.initials: BR
authors.lastname: Cho
authors.forename: Ji-Sook
authors.initials: JS
authors.lastname: Hahn
mesh_terms: D018929:Cell Culture Techniques; D005285:Fermentation; D017353:Gene Deletion; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D010626:Phenylethyl Alcohol / Q000032:analysis / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D000637:Transaminases / Q000235:genetics / Q000378:metabolism
chemical_list: C585338:Aro80 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D000637:Transaminases; C541341:aromatic aminotransferase II, S cerevisiae; D010626:Phenylethyl Alcohol
keywords: 2-phenylethanol; Ald3; Aro10; Aro80; Aro9; Ehrlich pathway; Saccharomyces cerevisiae