Improved Synthesis of Furfurylamine from a High Titer of Biomass-Derived Furfural by a Thermostable Triple Mutant ω-Transaminase in a Three-Component Deep Eutectic Solvent ChCl/Lactic Acid/Malonic Acid System
Lei Li, Qing Li, Junhua Di, Yu-Cai He, Cuiluan Ma
Abstract
Furfurylamine (FLA) is widely utilized in manufacturing polymers, food additives, fibers, fuel additives, flavors, and pharmaceuticals. Lignocellulose was tandemly transformed to furfurylamine by combining chemocatalysis with biocatalysis in a three-component deep eutectic solvent (3c-DES)–H 2 O in this work. Biomass-derived d -xylose (300 mM) was transformed with 3c-DES ChCl/MA/LA (15 wt %) [choline chloride (ChCl), malonic acid (MA), and lactic acid (LA)] at 190 °C for 45 min to produce furfural (70.6% yield). A robust triple mutant Aspergillus terreus ω-transaminase HNILQE with high biocatalytic activity and thermostability was obtained through a consensus strategy [Q97E (glutamine to glutamic acid), H210N (histidine to asparagine), I77L (isoleucine to leucine)]. HNILQE could aminate d -xylose-derived furfural to furfurylamine (97.6% yield), reaching a productivity of 0.98 g furfurylamine/g furfural (cal. 0.44 g furfurylamine/g d -xylose). High titer of biobased furfural (500 mM) was transformed to FLA (95.8% yield, >99% selectivity) in ChCl/MA/LA–H 2 O. A highly efficient manufacture of furfurylamine from high loading of furfural by this robust triple mutant HNILQE biocatalyst was successfully realized in the established eco-friendly medium. This established chemoenzymatic process can be utilized for efficient manufacture of biobased furans in the green and sustainable approach.