State Key Laboratory of Cellular Stress Biology School of Life Sciences, Xiamen University Fujian, Xiamen, 361102, P. R. China.
Chem Asian J. 2020 Apr 1;15(7):1018-1021. doi: 10.1002/asia.201901680. Epub 2020 Feb 25.
Benzyl alcohol is a naturally occurring aromatic alcohol and has been widely used in the cosmetics and flavor/fragrance industries. The whole-cell biotransformation for synthesis of benzyl alcohol directly from bio-based L-phenylalanine (L-Phe) was herein explored using an artificial enzyme cascade in Escherichia coli. Benzaldehyde was first produced from L-Phe via four heterologous enzymatic steps that comprises L-amino acid deaminase (LAAD), hydroxymandelate synthase (HmaS), (S)-mandelate dehydrogenase (SMDH) and benzoylformate decarboxylase (BFD). The subsequent reduction of benzaldehyde to benzyl alcohol was achieved by a broad substrate specificity phenylacetaldehyde reductase (PAR) from Solanum lycopersicum. We found the designed enzyme cascade could efficiently convert L-Phe into benzyl alcohol with conversion above 99%. In addition, we also examined L-tyrosine (L-Tyr) and m-fluoro-phenylalanine (m-f-Phe) as substrates, the cascade biotransformation could also efficiently produce p-hydroxybenzyl alcohol and m-fluoro-benzyl alcohol. In summary, the developed biocatalytic pathway has great potential to produce various high-valued fine chemicals.
苯甲醇是一种天然芳香醇，已广泛应用于化妆品和香料/香精行业。本研究利用大肠杆菌中的人工酶级联反应，从生物基 L-苯丙氨酸（L-Phe）直接合成苯甲醇的全细胞生物转化方法。通过四个异源酶促步骤将 L-Phe 转化为苯甲醛，这四个步骤分别为 L-氨基酸脱氨酶（LAAD）、羟甲基扁桃酸合酶（HmaS）、（S）-扁桃酸脱氢酶（SMDH）和苯甲酰甲酸脱羧酶（BFD）。随后，利用具有广泛底物特异性的番茄苯乙醛还原酶（PAR）将苯甲醛还原为苯甲醇，转化率超过 99%。此外，我们还考察了 L-酪氨酸（L-Tyr）和间氟苯丙氨酸（m-f-Phe）作为底物时的情况，该级联生物转化也可以有效地生产对羟基苯甲醇和间氟苯甲醇。总之，该生物催化途径具有很大的潜力，可以生产各种高附加值的精细化学品。
