Discovery, Modification, and Immobilization of a Lysine Decarboxylase from Pantoea alhagi for Efficient Cadaverine Production

Biocatalytic conversion of l-lysine to cadaverine, a key monomer for biobased nylons, holds significant industrial importance, rendering the development of efficient biocatalysts highly imperative. Herein, we identified a lysine decarboxylase from Pantoea alhagi (PaLDC) and introduced an intramolecular disulfide bond (F14C/K44C) through structure-guided rational design, yielding a promising biocatalyst (M1 mutant) with substantially enhanced thermo- and alkali-stability for efficient cadaverine production. In addition, the M1 mutant was immobilized on LX-EPHA (an amino resin) to further improve its stability and reusability, which was finally integrated with a rotating bed reactor (RBR), enabling the transformation of l-lysine (2 M) to cadaverine with 99.9% conversion. This RBR system retained >85% of its initial activity over 20 biocatalyst reuse cycles. The integration of enzyme engineering, enzyme immobilization, and bioreactor technology provides an efficient and industrially viable platform for scalable production of cadaverine.