Sensing, Uptake and Catabolism of L-Phenylalanine During 2-Phenylethanol Biosynthesis via the Ehrlich Pathway in Saccharomyces cerevisiae

Abstract

2-Phenylethanol (2-PE) is an important flavouring ingredient with a persistent rose-like odour, and it has been widely utilized in food, perfume, beverages, and medicine. Due to the potential existence of toxic byproducts in 2-PE resulting from chemical synthesis, the demand for “natural” 2-PE through biotransformation is increasing. L-Phenylalanine (L-Phe) is used as the precursor for the biosynthesis of 2-PE through the Ehrlich pathway by Saccharomyces cerevisiae. The regulation of L-Phe metabolism in S. cerevisiae is complicated and elaborate. We reviewed current progress on the signal transduction pathways of L-Phe sensing, uptake of extracellular L-Phe and 2-PE synthesis from L-Phe through the Ehrlich pathway. Moreover, the anticipated bottlenecks and future research directions for S. cerevisiae biosynthesis of 2-PE are discussed.

Combining metabolite doping and metabolic engineering to improve 2-phenylethanol production by engineered cyanobacteria

“…Thus, we almost doubled 2-PE yield, up to 222 mg/gDW, when we supplemented L-Phe to the induced cyanobacteria for the heterologous expression of the 2-PE synthetic pathway, but any particular increase in 2-PE concentration was recorded. The Phe addition is a consolidated strategy adopted to push 2-PE production by yeast, where the Ehrlich pathway is exploited (Liu et al, 2019b;Gu et al, 2020;Dai et al, 2021). The Ehrlich pathway is composed of three enzymatic steps, where L-Phe is firstly Effects of medium supplementation with L-phenylalanine on the metabolic network of the S. elongatus PCC 7942 mutant producing 2phenylethanol.…”

“…Plant-extracted 2-PE costs 1,000 US$/kg and suffers from economics and scalability for a sustainable industrial production ( Liu et al, 2018 ; Qian et al, 2019 ). On the other hand, biotechnologically synthesized 2-PE has a value of around 220 US$/kg ( Mitri et al, 2022 ), so the 2-PE synthesis by microorganisms has been emerging as appealing bioproduction system, alternatively to plant extraction ( Gu et al, 2020 ; Kong et al, 2020 ; Dai et al, 2021 ; Zhu et al, 2021 ).…”

Aminotransferase SsAro8 Regulates Tryptophan Metabolism Essential for Filamentous Growth of Sugarcane Smut Fungus Sporisorium scitamineum

“…We next investigated TryOH biosynthesis pathway in S. scitamineum . The yeast AAT Aro8 has been reported to catalyze deamination of aromatic amino acids, including tryptophan, as the first step of Ehrlich pathway to produce the corresponding aromatic alcohols ( 24 – 26 ). On the other hand, Ustilago maydis tryptophan aminotransferases Tam1 and Tam2 were reported responsible for tryptophan-dependent IAA biosynthesis, catalyzing deamination of tryptophan ( 27 ).…”

Effect of co‐fermentation and sequential fermentation of Candida versatilis and Lactococcus lactis subsp. cremoris on unsalted pork hydrolysates components

“…Single C. versatilis also produced a significantly higher amount of 2phenylethyl alcohol (222.84 ng mL À1 ) than the other fermented samples. This compound was likely produced from phenylalanine via the Ehrlich pathway during fermentation, potentially giving a floral and rose-like odour (Dai et al, 2021). High amounts of hexanoic acid (226.22 ng mL À1 ) and 1-hexanol (248.46 ng mL À1 ) were detected, which were mostly from oxidation and reduction of hexanal, respectively, during fermentation.…”