Metabolic engineering of Escherichia coli for production of 2-phenylethanol from renewable glucose.

2-Phenylethanol (2-PE) is an important aromatic alcohol with a rose-like odor and has wide applications. The present work aims to construct a synthetic pathway for 2-PE synthesis from glucose in Escherichia coli. First, the genes adh1 (encoding alcohol dehydrogenase) and kdc (encoding phenylpyruvate decarboxylase) from Saccharomyces cerevisiae S288c and Pichia pastoris GS115 were investigated in E. coli, respectively, and single overexpression of adh1 or kdc significantly increased 2-PE accumulation. When co-overexpressing adh1 and kdc, 2-PE was increased up to 130 from 57 mg/L. Furthermore, by optimizing coordinated expression of the four committed genes aroF, pheA, adh1 and kdc, 2-PE was improved to 285 mg/L which was the highest production of 2-PE by the recombinant E. coli system. In addition, our results also demonstrated that the tyrB gene, which encodes aromatic-amino-acid transaminase, plays an important role on 2-PE synthesis.