Abstract 4-Ethylphenol (4-EP) is an industrially versatile commodity chemical widely applied in the pharmaceutical and food industries. In this study, an artificial biosynthetic pathway was constructed in Escherichia coli for production of 4-ethylphenol from simple sources of carbon. The pathway consists of the tal, pad and vpr genes, which encode tyrosine ammonia lyase (TAL), phenolic acid decarboxylase (PAD) and vinylphenol reductase (VPR), respectively. Our results confirmed that the TAL from Saccharothrix espanaensis possessed higher catalytic activity than the TAL from Rhodobacter sphaeroides for biosynthesis of p-hydroxycinnamic acid. The low solubility of Lactobacillus plantarum VPR (LpVPR) in E. coli was a critical factor limiting its availability in the biosynthetic pathway. The solubility of LpVPR was improved by E. coli strain and induction condition optimization. Under the optimized conditions, the engineered E. coli TransB-TPV produced as high as 110 mg/L 4-EP at 37 ℃ in Terrific Broth (TB) medium with glycerol as carbon source after cultivation of 48 h. This study provided a new and feasible strategy for biosynthesis of 4-EP from simple sugars, which may provide a basis for future large-scale industrial application.

中文翻译：

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4-乙基苯酚在工程大肠杆菌中的异源合成

摘要 4-乙基苯酚（4-EP）是一种工业通用的日用化学品，广泛应用于制药和食品工业。在这项研究中，在大肠杆菌中构建了一条人工生物合成途径，用于从简单的碳源生产 4-乙基苯酚。该通路由 tal、pad 和 vpr 基因组成，分别编码酪氨酸解氨酶 (TAL)、酚酸脱羧酶 (PAD) 和乙烯基苯酚还原酶 (VPR)。我们的结果证实，西班牙糖丝菌的 TAL 比球形红杆菌的 TAL 对对羟基肉桂酸的生物合成具有更高的催化活性。植物乳杆菌 VPR (LpVPR) 在大肠杆菌中的低溶解度是限制其在生物合成途径中可用性的关键因素。LpVPR 的溶解度被 E 提高。大肠杆菌菌株和诱导条件优化。在优化条件下，工程大肠杆菌TransB-TPV在以甘油为碳源的Terrific Broth (TB)培养基中，在37 ℃培养48 h后可产生高达110 mg/L的4-EP。该研究为单糖生物合成4-EP提供了一种新的可行的策略，可为未来的大规模工业应用提供基础。