Bioproduction of Biobased 2,5-Bis(hydroxymethyl) Furan and Its Derivatives from Seed-Derived 5-Hydroxymethylfurfural with Mutant Aryl Alcohol Oxidase from <i>Mycobacterium</i> MS1601

In this study, the selectivity of biological oxidation and bioreduction reactions was successfully regulated by tuning the reaction system and introducing auxiliary additives. In an aqueous system, AOYF cells expressing a mutant aryl alcohol oxidase (AAO) from Mycobacterium MS1601 as a biocatalyst catalyzed the conversion of 125 mM HMF to FFCA (78.7% yield), DFF (19.8% yiled), and a small amount of FDCA (1.5% yield). In contrast, in the deep eutectic solvent Betaine:Lactic acid–water system supplemented with D -fructose, Escherichia coli AOYF cells preferentially catalyzed the conversion of 125 mM HMF to BHMF (84.5% yield) along with a minor amount of DFF (15.5% yield). In addition, this work proposes a chemobiocatalytic strategy for converting fruit waste into BHMF. First, Betaine:Lactic acid (15 wt %) was employed to catalyze biomass wastes (e.g., lotus seed, lychee seed, longan seed, mango seed, jackfruit seed, loquat seed, chestnut kernel, and spent coffee grounds) into HMF (180 °C, 30 min). Among these biomass wastes, jackfruit seed could be transformed into HMF, reaching up to 109.8 mM. Jackfruit seed-derived HMF could be biocatalytically converted to BHMF (0.297 g/g jackfruit seed) and DFF (0.054 g/g jackfruit seed) using E. coli AOYF cell as a biocatalyst and D -fructose (0.6 mol of D -fructose/mol of HMF) as a cosubstrate. In conclusion, this work provides a sustainable route for producing value-added BHMF and other biofuran chemicals from HMF and fruit seed wastes.