Adsorption of Lysozyme on Biomass Charcoal Powder Prepared from Plant Biomass Wastes

The adsorption of chicken egg-white lysozyme onto biomass charcoal powder (BCP), which was prepared from plant biomass wastes such as dumped adzuki beans and bamboos by pyrolysis without combustion under a nitrogen atmosphere and grinding with a jet mill, has been examined. The adsorption isotherms were successfully correlated by the Freundlich equation. The amount of lysozyme adsorbed on BCP is dramatically dependent upon the solution pH and temperature. A maximum adsorption is observed near neutral pH, suggesting that the adsorption is mainly attributable to the electrostatic interaction between the positive charge of enzymes and the negative charge on the surface of BCP. Plots of the amount of lysozyme adsorbed versus temperature exhibit an optimum temperature. The BCP is characterized by Raman spectroscopy, SEM, specific surface area, zeta potential, solid-state CP/MAS C-13-NMR spectroscopy, and X-ray photoelectron spectroscopy.