Improved aromatic alcohol production by strengthening the shikimate pathway in Saccharomyces cerevisiae

Abstract

Aromatic alcohols, such as tyrosol and 2-phenylethanol, are widely used in various industries owing to their superior flavors and properties. In this study, a yeast metabolic modification platform for the de novo synthesis of tyrosol and 2-phenylethanol was established. Alleviation of the feedback inhibition and overexpression of 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase and chorismate mutase were achieved by introducing aroGD146N and pheAfbr genes from Escherichia coli. Shikimate kinase (aroL) and shikimate dehydrogenase (ydiB), analogues of the penta-functional enzyme Aro1p, were overexpressed to release the metabolic bottlenecks. Furthermore, in addition to ARO10-overexpression, ARO9 was disrupted to reduce the by-product generation. Finally, by introducing EcaroGD146N, EcpheAfbr, EcydiB and EcaroL in the ARO9-deleted strain, together with overexpression of transketolase (TKL1) and phenylpyruvate decarboxylase (ARO10), the engineered strain JM26 was constructed. Using glucose as the sole carbon source, JM26 achieved 541 mg/L (73.5 mg/g DCW) of tyrosol and 643 mg/L (92.0 mg/g DCW) of 2-phenylethanol, which is 5.7-fold and 6.1-fold higher than the control strain, respectively. These results demonstrate that the strategies applied improved de novo production of tyrosol and 2-phenylethanol, and showed potential for application as a metabolic chassis for other aromatic compounds in Saccharomyces cerevisiae and the exploration of their biological functions.