Metabolic engineering of Escherichia coli for de novo production of lauryl glucoside

Lauryl glucoside, a non-ionic surfactant used in various cosmetic products, is valued for its biodegradability and gentleness on the skin. However, its current production through chemical synthesis is considered unsustainable, necessitating the search for alternative methods. In this work, we engineered Escherichia coli BL21(DE3) with a novel lauryl glucoside biosynthetic pathway. Optimisation of 1-dodecanol, a lauryl glucoside precursor, was first implemented. Under optimised conditions, the strain produced 1-dodecanol at a titre of 185.39 ​± ​3.62 ​mg/L and a yield of 11.60 ​± ​0.29 ​mg/g glucose. These conditions were subsequently used to identify UDP-glycosyltransferases capable of converting 1-dodecanol to lauryl glucoside. Among six UDP-glycosyltransferases, MtH2 from Medicago truncatula showed the highest activity, with a titre and a yield of 0.72 ​± ​0.07 ​mg/L and 0.06 ​± ​0.004 ​mg/g glucose, respectively. The lauryl glucoside biosynthesis by MtH2 was confirmed using HPLC and targeted LC-MS. Moreover, the limited availability of 1-dodecanol was primarily identified as the bottleneck in this pathway. Supplementing the cells with twice the amount of 1-dodecanol led to an increase in lauryl glucoside production, achieving a titre of 13.44 ​± ​0.21 ​mg/L and a yield of 1.35 ​± ​0.04 ​mg/g glucose. Fermentation products of all strains were also monitored and suggested the redirection of carbon flux from acetate to the desired products. These findings demonstrate the successful characterisation of a newly designed lauryl glucoside biosynthetic pathway in engineered E. coli and highlight substrate limitation as a bottleneck in the pathway offering a sustainable alternative to traditional production methods. • E. coli BL21 (DE3) was engineered to produce lauryl glucoside using a novel biosynthetic pathway. • Six UDP-glycosyltransferases were expressed and characterised for lauryl glucoside conversion from 1-dodecanol. • Low UDP-glycosyltransferase activity and limited availability of 1-dodecanol were primarily determined to be the bottlenecks in lauryl glucoside synthesis. • Fermentation profiles of 1-dodecanol and lauryl glucoside strains indicated carbon flux was redirected from acetate.