Efficient Production of 2,5-Furandicarboxylic Acid via Chemobiocatalytic Sequential Catalysis of Bread Waste in a One-Pot, Three-Step Process Manner in a Benign Reaction System

2,5-Furandicarboxylic acid (FDCA) is an essential biobased dibasic acid with a structure similar to that of the petroleum-based bulk chemical terephthalic acid. In this research, a highly effectual catalytic process was acquired to transform waste bread (WB) into FDCA in a one-pot, three-step approach. First, 5-hydroxymethylfurfural (24.8 wt % yield) was acquired from WB (40 g/L) in the deep eutectic solvent (DES) choline chloride:lactic acid (ChCl:LA)-H₂O (ChCl:LA, 15 wt %) medium for 15 min at 180 °C. The WB-derived HMF was oxidized to 2,5-furandicarboxaldehyde (97.4% yield) using Escherichia coli pRSFDuet-GOase within 5 h. Afterward, WB-derived DFF was transformed to FDCA (0.291 g of FDCA per g of WB) using immobilized lipase powder CL (CL-IM) in tert-butanol:ethyl acetate (t-BuOH:EtOAc = 1:1, v/v) at 40 °C for 9 h. This chemobiological route from food waste to FDCA afforded a new idea for valorization of waste into valuable biobased chemicals in a green and effectual way.