Multilayer Engineering of Enzyme Cascade Catalysis for One-Pot Preparation of Nylon Monomers from Renewable Fatty Acids

Enzyme cascade catalysis has critical problems in obtaining the high concentrations of products, such as the low stabilities and activities of biocatalysts and the inhibition by hydrophobic reactants at high concentrations to biocatalysts. Here, we performed multilayer engineering of enzyme cascade catalysis to produce C11 nylon monomers at commercially viable concentrations from ricinoleic acid. The catalysis was driven by engineered Escherichia coli-based whole-cell biocatalysts and cell-free enzymes (i.e., lipases). Stabilities and activities of the biocatalysts were improved by engineering the bottleneck enzyme Baeyer-Villiger monooxygenase and introducing a cofactor regeneration system. The inhibitory effects of the byproducts n-heptanoic acid and pyruvate on the cascade enzymes were overcome, and the products were simply recovered in situ by engineering of reactions with the addition of an adsorbent resin. We obtained 248 mM undecanedioic acid or 232 mM 11-aminoundecanoic acid as a nylon monomer from 300 mM ricinoleic acid by multilayer engineering. The concentration was 500- and 640-fold higher than those produced by nonengineering, respectively. We have also simply isolated the C11 nylon monomers via solvent extraction to a rather high purity. This study will contribute to the industrial enzyme cascade synthesis of nylon monomers in an environmentally-friendly route from renewable biomass.