魔芋葡甘聚糖酶解历程反应-扩散动力学

引 言 近年来,天然多糖的酶促水解在生物能源炼制、油气开采、药物缓释、功能保健中得到广泛应用,涉及能源、资源、医药、食品等国计民生行业,其研究引起了众多学者的极大兴趣,成为各国科技战略的重要组成部分.

Reaction-diffusion kinetics for enzymatic hydrolysis of konjac glucomannan

Enzymatic hydrolysis of konjac glucomannan（KGM）by β-mannanase was studied at constant mass ratio of enzyme to substrate to investigate the reaction-diffusion mechanism.By using size exclusion chromatography（SEC），the changes in molecular weight distribution of KGM were followed during the process of hydrolysis.When the ratio of enzyme to substrate was constant，the changes in molecular weight at different KGM concentrations were remarkably different，which showed that the reaction depended on the diffusion of enzyme.The changes in molecular weight showed a zero-order kinetics.Integrating the empirical reaction kinetics and diffusion characteristics，a reaction-diffusion model was established from a series of chromatographic results.But the degradation rate was shown to be greatly affected by the diffusion of enzyme as well as the concentration of substrate.This equation of reaction kinetics indicated the importance of diffusion，and the experimental data can be well predicted at semi dilute concentrations of KGM.