Developing an efficient strategy for immobilization of PHB depolymerase on magnetite-based nanoparticles for degrading polyhydroxybutyrate in acidic conditions

Several approaches towards the efficient immobilization of poly-3-hydroxybutyrate (PHB) depolymerase from Streptomyces ascomycinicus (PhaZ(Sa)) on magnetic-silanized nanoparticles have been explored in order to accomplish the preparation of an active immobilized biocatalyst in PHB hydrolysis in acid conditions. A simple non-covalent adsorption of PhaZ(Sa) to silanized magnetic particles at acidic pH during a short incubation time allowed the preparation of immobilized biocatalysts with increased specific activity. In contrast, covalent binding of PhaZ(Sa) to silanized magnetite by different methods led to immobilized biocatalysts whose retained activity were low or void.