화학공학소재연구정보센터
Biotechnology and Bioengineering, Vol.111, No.1, 115-124, 2014
Metabolic Engineering of Saccharomyces cerevisiae for the Production of 2-Phenylethanol Via Ehrlich Pathway
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 4.8g/L 2-PE in a medium containing 10g/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 6.1g/L 2-PE in organic phase with the molar yield of 82.5%, which is about ninefold increase compared with wild type. Biotechnol. Bioeng. 2014;111: 115-124. (c) 2013 Wiley Periodicals, Inc.