Establishment of Novel Biosynthetic Pathways for the Production of Salicyl Alcohol and Gentisyl Alcohol in Engineered Escherichia coli

Abstract

Salicyl alcohol and gentisyl alcohol are two important phenolic alcohols that possess significant biological activities and pharmaceutical properties. Here, we report establishment of novel biosynthetic pathways for microbial production of salicyl alcohol and gentisyl alcohol from renewable feedstocks. We first examined the promiscuity of the carboxylic acid reductase CAR toward salicylic acid and 2,5-DHBA, which enabled efficient synthesis of salicyl alcohol and gentisyl alcohol. Then, we employed a novel salicylic acid 5-hydroxylase to achieve 2,5-DHBA production from salicylic acid. After that, the de novo biosynthetic pathways were assembled and optimized by programming the carbon flux into the shikimate pathway. The final titers of salicyl alcohol and gentisyl alcohol reached to 594.4 mg/L and 30.1 mg/L, respectively. To our knowledge, this work achieved microbial production of salicyl alcohol and gentisyl alcohol for the first time. Our present study also demonstrated application of enzyme promiscuity to establish non-natural biosynthetic pathways for the production of high-value compounds.

Extending the shikimate pathway for microbial production of maleate from glycerol in engineered Escherichia coli

“…Previously, we identified a salicylate 5‐hydroxylase SalABCD from R. eutropha H16 that could hydroxylate salicylate into gentisate. By exogenously feeding salicylate, the wildtype E. coli strains carrying salABCD generated 0.62 g/L gentisate after 24 h cultivation (Shen et al, 2018). We believe that the current conversion rate of SalABCD is not high enough to produce maleate.…”

“…We previously reported biosynthesis of gentisate from salicylate for the first time by identification of a salicylate 5‐hydroxylase from Ralstonia eutropha H16 (Sun et al, 2015). However, the catalytic activity of this enzyme was relatively low and only 0.62 g/L gentisate was produced by directly supplementing salicylate into the cultures (Shen et al, 2018). In This study, we constructed a novel alternative route for maleate synthesis in E. coli .…”

Gentisyl Alcohol Inhibits Proliferation and Induces Apoptosis via Mitochondrial Dysfunction and Regulation of MAPK and PI3K/AKT Pathways in Epithelial Ovarian Cancer Cells

“…There are also ways to biosynthesize gentisyl alcohol via engineered Escherichia coli . [13]. Gentisyl alcohol has already been reported to inhibit cell proliferation in human breast and colon cancer and its derivatives have anti-cancer effects on lung carcinoma and leukemia cell lines [11].…”

Emerging tools, enabling technologies, and future opportunities for the bioproduction of aromatic chemicals

“…Following extensive host engineering to enhance endogenous chorismate production, Noda and co‐workers introduced seven unique downstream pathway modules to produce seven unique chorismate‐derived products, including salicylate, phenol, 3‐hydroxybenzoate, and cis,cis ‐muconic acid, among others . This approach was further exploited by Shen et al ., in this case to convert chorismate to either salicyl alcohol (precursor to the anti‐inflammatory, salicin) or gentisyl alcohol (an antioxidant and antibiotic); both through salicylate as a common intermediate …”