Immobilization of the Magnetic Nanoparticles with Alkaline Protease Enzyme Produced by Enterococcus hirae and Pseudomonas aeruginosa Isolated from Dairy Effluents

Protease is an enzyme which has a wide range of applications in various fields. Extracellular protease was produced from Pseudomonas aeruginosa and Enterococcus hirae which were isolated from the effluents of diary industries. Protease immobilized with super paramagnetic nanoparticles was characterized by DLS, XRD and TEM methods in relation to their size and structure. The protease enzyme was bound to magnetic nanoparticles via surface transformation technique including Silica coated magnetic Nano composite, amine and cysteine functioned Nano composite formation. Successful binding of protease onto the particles was confirmed by TEM imaging. The maximal enzyme activity of immobilized protease was determined using universal protease assay and was found to be 105 mu g mL(-1) & 290 mu g mL(-1) for Pseudomonas sp. and Enterococcus sp. respectively. The immobilization capacity of protease onto nanoparticles was 6000 mu M/g. The stability of the immobilized enzyme increased in comparison with the free enzyme. Overall, this study showed that the stability and activity of the protease was enhanced by immobilization to the magnetic nanoparticles. This suggested that immobilized enzyme on the magnetic beads of nanoparticles could be used in an interesting range of applications, both in broader temperature and pH ranges, also permitting magnetic recovery of the enzyme for reuse or purification of the product.