Reusable carboxylesterase immobilized in ZIF for efficient degradation of chlorpyrifos in enviromental water

The past few decades have witnessed biodegradation of pesticides as a significant method in remediation of the environment for its specificity, efficiency and biocompatibility. However, the tolerability and recyclability of the enzymes in pesticide degradation and the development of enzymes that biodegrad pesticides are still urgent problems to be solved so far. Herein, a novel hyper-thermostable and chlorpyrifos-hydrolyzing carboxylesterase EstC was immobilized by biomineralization using zeolitic imidazolate framework (ZIF), one of the metal-organic frameworks (MOFs) with highly diverse structure and porosity. Compared with free enzyme, EstC@ZIF with a cruciate flower-like morphology presented scarcely variation in catalytic efficiency and generally improved the tolerance to organic solvents or detergents. Furthermore, there was scarcely decrease in the catalytic efficiency of EstC@ZIF and it also showed good reusability with about 50% residual activity after 12 continuous uses. Notably, EstC@ZIF could be used in actual water environment with an excellent value of degradation rate of 90.27% in 120 min, and the degradation efficiency remained about 50% after 9 repetitions. The present strategy of immobilizing carboxylesterase to treat pesticide-contaminated water broadens the method of immobilized enzymes on MOFs, and envisions its recyclable applicability in globe environmental remediation. We investigated herein an immobilized carboxylesterase with metal organic frameworks as a carrier (EstC@ZIF) by using synthetic strategy of biomineralization. The EstC@ZIF with remarkable specific surface area and stability to organic solvents, could be applied to degrade chlorpyrifos of actual water covered with farmland or orchard. [Display omitted] •Carboxylesterase was firstly immobilized by zeolitic imidazolate framework.•The morphology of EstC@ZIF was highly correlation with protein concentration.•The material showed excellent resistance to methanol and SDS.•EstC@ZIF degraded 90% of chlorpyrifos for 120 min in water near farmland and orchard.•EstC@ZIF possessed remarkable recyclability toward chlorpyrifos.