Neutral lipase from aqueous solutions on chitosan nano-particles

作者：Tang, Zhen-Xing; Shi, Lu-E; Qian, Jun-Qing^*

来源：Biochemical Engineering Journal, 2007, 34(3): 217-223.

DOI：10.1016/j.bej.2006.12.022

• chitosan
• nano-particles
• neutral lipase
• sorption kinetics
• sorption mechanism

The size of chitosan nano-particles had been prepared by ionic cross-linking of chitosan and tri-polyphosphate (CS-TPP), which were well dispersed and stable in aqueous solution. The physicochemical properties of nano-particles were characterized by IR spectra, SEM. Its sorption kinetics and sorption mechanism for neutral lipase were studied. The effect factors of adsorption kinetics were investigated, such as neutral lipase concentration, chitosan nano-particles solution concentration, adsorption temperature, size of chitosan nano-particles, stirring rate, solution pH, etc. Adsorption of neutral lipase on chitosan nano-particles was fitted into Lagergren first-order equation at initial neutral lipase of 3.0 mg/ml (pH 7.0). The first-order constant for neutral lipase was 23.34 h(-1). When neutral lipase concentration was controlled under certain region, it was fitted into Freundlich isothermal linear equation. Mechanism of adsorption for neutral lipase was presumed by analyzing IR spectra. The hydrogen in the carboxyl group was connected with electronegative oxygen. Electron pair was attractive to oxygen, so hydrogen atom became cation and proton. When electronegative neutral lipase was closed to chitosan nano-particle, the hydrogen bond might be formed. It was the main force between hydroxyl group, NH2 group and neutral lipase.

• 出版日期2007-6
• 单位浙江工业大学