One-pot one-step enzymatic synthesis of 5-(aminomethyl)-2-furancarboxylic acid from 5-(hydroxymethyl) furfural

Abstract

5-(aminomethyl)-2-furancarboxylic acid (AMFCA) represents a biogenic replacement to fossil-based monomers for the production of semi-aromatic polyamides, thermoplastics widely used in the automotive, electrical and packaging industries. AMFCA has been synthetized via chemical, chemo-enzymatic and enzymatic one-pot two-step transformations. Herein, the conversion of 5-(hydroxymethyl)-furfural (HMF) to AMFCA is explored through a one-pot, one-step, cell-free, enzymatic process, reaching titers in the range of 3.35-4.62 g·L^-1. The four-enzyme cascade includes an engineered HMF oxidase from Methylovorus sp. MP688, an aldehyde dehydrogenase from Sphingobium sp. SYK-6 and an omega-transaminase from Chromobacterium violaceum as main biocatalysts. L-alanine is used as amine donor, sustainably regenerated by an alanine dehydrogenase, which also guarantees an intrinsic nicotinamide cofactor balance. As environmental metrics, the E-factor and the “Global Warming Potential” (GWP, kg CO2 · kg AMFCA^-1) are introduced for both the upstream and the dowsntream of AMFCA production for the first time. The sustainability assessment provides valuable insights on the hotspots to be improved for minimized environmental burden: operating at high substrate loadings, generation of wastewater effluents that can be mildly treated, optimized volume-to-product ratio in chromatographic steps, and introduction of renewable energy in the chemical plant.