The aim of this study was to immobilize of lysozyme onto bacterial cellulose nanofibers (BCNF) using physical absorption method. Antimicrobial activity and other properties of immobilized lysozyme and also morphological characteristics of BCNF were studied. Activity of lysozyme was decreased about 12% after immobilization. The lysozyme concentration of 1mg/ml was chosen for next studies on immobilized enzyme. The optimum pH and temperature were recorded as 7 and 45°C, respectively for immobilized enzyme. Storage stability was increased and immobilized lysozyme exhibited more than 70% of its initial activity after 9 cycles. Kinetic parameters of Km and Vmax were 31.18μg/ml and 112.35 ΔOD/min, respectively for immobilized enzyme. Antimicrobial activity of lysozyme against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Yersinia entrocolitica, Aspergillus niger and Saccharomyces serviseae was increased after immobilization. The XRD analyses showed a decrease in diffraction intensities and crystallinity index of BCNF after immobilization of lysozyme. According to the results of scanning electron microscopy (SEM), the diameter of nanofibers was increased by lysozyme incorporation. This study demonstrates the potential for the use of BCNF as carrier for lysozyme immobilization.
Keywords: Antimicrobial activity; Bacterial cellulose; Immobilization; Lysozyme; Morphology.
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