A simple and efficient biodegradation route for nitroaromatic compounds using a nitroreductase from Bacillus subtilis and its "cell-like" immobilized form.

. To enhance enzyme stability and eliminate repeated cofactor addition, a "cell-like" co-encapsulation system comprising NRBs, glucose dehydrogenase (GDH), and the cofactor NADH was constructed using ZIF-67 as the encapsulation material. In this design, NRBs was purified and immobilized on polyvinylpyrrolidone (PVP)-modified ZIF-L (P-ZIF-L), whereas NADH and GDH were co-grafted onto poly(acrylamide-co-diallyldimethylammonium chloride) (PADD) to form a PNG complex. The resulting NRBs@P-ZIF-L@PNG@ZIF-67 composite exhibited enhanced catalytic activity, stability, and substrate scope. Furthermore, the "cell-like" co-immobilized system retained 65.0 ± 3.5% of its catalytic yield toward aniline formation after seven reaction cycles, whereas the NRBs-GDH recombinant whole-cell catalyst showed complete deactivation under identical conditions. This work establishes a rapid, simple, green, and sustainable biodegradation strategy for nitroaromatic pollutants, demonstrating the feasibility of using a "cell-like" co-immobilized enzyme system for efficient and reusable biocatalysis.