title: Immobilization to Positively Charged Cellulose Nanocrystals Enhances the Antibacterial Activity and Stability of Hen Egg White and T4 Lysozyme.
abstract: Antibacterial bionanostructures were produced from cellulose nanocrystals (CNC) with immobilized lysozyme from hen egg white (HEW) and T4 bacteriophage, respectively. The nanocrystals were prepared from microcrystalline cellulose by ammonium persulfate oxidation with a yield of 68% and having an average size of 250 nm and low polydispersity index. HEW lysozyme (HEWL) and T4 lysozyme (T4L) were immobilized to CNC by different mechanisms including adsorption and covalent coupling to carbodiimide-activated carboxylate groups and to glutaraldehyde-activated aminated CNC (Am-CNC), respectively. The effect of immobilization on the enzymatic activity (both lytic and hydrolytic) and antibacterial activity of the lysozymes was studied using different methods. Am-CNC-lysozyme conjugates retained the highest lytic activity, 86.3% and 78.3% for HEWL and T4L, respectively. They also showed enhanced bactericidal activity with high potency against Gram-positive as well as Gram-negative bacteria in a relatively shorter time as compared to the free enzymes and resulted in extensive cellular damage, as shown by transmission electron microscopy. The enhanced antibacterial activity was correlated with the increase in zeta potential of Am-CNC-lysozyme conjugates. The immobilized lysozyme preparations further exhibited enhanced storage stability at 4 and 22 °C.
authors.affiliation: Biotechnology, Department of Chemistry, Center for Chemistry and Chemical Engineering, Lund University , P.O. Box 124, SE-221 00 Lund, Sweden.|Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University , 715 24 Assiut, Egypt.
authors.forename: Adel
authors.identifier: http://orcid.org/0000-0003-1882-5820
authors.initials: A
authors.lastname: Abouhmad
authors.affiliation: Department of Microbiology and Immunology, Faculty of Pharmacy, Beni-Suef University , 625 11 Beni-Suef, Egypt.
authors.forename: Tarek
authors.identifier: http://orcid.org/0000-0001-8644-2640
authors.initials: T
authors.lastname: Dishisha
authors.affiliation: Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University , 115 62 Cairo, Egypt.
authors.forename: Magdy A
authors.identifier: http://orcid.org/0000-0002-9292-7115
authors.initials: MA
authors.lastname: Amin
authors.affiliation: Biotechnology, Department of Chemistry, Center for Chemistry and Chemical Engineering, Lund University , P.O. Box 124, SE-221 00 Lund, Sweden.
authors.forename: Rajni
authors.identifier: http://orcid.org/0000-0001-5229-5814
authors.initials: R
authors.lastname: Hatti-Kaul
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D017122:Bacteriophage T4 / Q000201:enzymology; D002482:Cellulose / Q000031:analogs & derivatives*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000494:pharmacology; D008837:Micrococcus / Q000187:drug effects; D009113:Muramidase / Q000737:chemistry* / Q000494:pharmacology; D053758:Nanoparticles / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D000900:Anti-Bacterial Agents; D004800:Enzymes, Immobilized; D002482:Cellulose; C421864:hen egg lysozyme; D009113:Muramidase