We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Cryogel-Immobilized Catalase as a Biocatalyst with Enhanced Stability Against Microplastics
Summary
Researchers developed a specialized gel material called a cryogel to stabilize the antioxidant enzyme catalase, which normally loses effectiveness in polluted environments. When tested against polystyrene microplastics, the immobilized catalase maintained significantly better activity and stability than the free enzyme. The study suggests this approach could help protect biological systems from the oxidative stress caused by microplastic contamination.
Catalase is a pivotal antioxidant enzyme that decomposes hydrogen peroxide and reduces oxidative stress. However, its low thermal and operational stability limits applications in challenging environments, particularly those contaminated with emerging pollutants such as polystyrene-based microplastics (PS-MPs). In this study, cryogels composed of Poly(2-hydroxyethyl methacrylate-co-allyl glycidyl ether) [Poly(HEMA-co-AGE)] were synthesized and evaluated as immobilization matrices to enhance catalase stability. Cryogels containing varying AGE concentrations were characterized using FT-IR, SEM, TEM, TGA, and BET analyses. The formulation with 250 µL AGE exhibited optimal physicochemical properties, including improved water retention, increased surface area, and high immobilization capacity (356.3 mg·g-1). Immobilized catalase maintained superior activity under PS-MP-induced stress across a range of concentrations (0-1.0 mg·mL-1), temperatures (4-60 °C), and exposure times (up to 5 h). Kinetic modeling revealed a significant improvement in substrate affinity, with Km decreasing from 54.9 to 17.1 mM, while Vmax decreased moderately. Long-term stability tests showed that immobilized catalase retained ~80% activity after 70 days at 4 °C and 55% after 15 reuse cycles. Desorption studies confirmed the reusability of the cryogel system. These findings suggest that Poly(HEMA-co-AGE) cryogels provide a robust and reusable platform for catalase stabilization, offering potential for applications such as wastewater treatment and biosensing in microplastic-contaminated systems.