Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
J Biosci Bioeng. 2013 Jun;115(6):668-73. doi: 10.1016/j.jbiosc.2012.12.014. Epub 2013 Jan 18.
Experimental studies were made for immobilization of enzymes on microporous polyvinylidene fluoride (PVDF) membrane in order to carry out enzymatic reaction of lactose into galacto-oligosaccharides using β-galactosidase. The present work, however, is the first part in the direction of enzymatic membrane reactor studies for carrying out reaction followed by membrane based separation to purify galacto-oligosaccharides out of reaction mixture. The middle of the three compartment cell, separated by two immobilized (enzyme) membranes, was utilized to feed lactose solution; whereas, adjacent compartments were filled with distilled water. The reacted mixture solution was analyzed for tri-, tetra- and penta-forms of GOS. The formation of product GOS strongly depended on varying amounts of initial lactose concentration (ILC). Total GOS formation increased from 7% to 28% for ILC from 50 to 200 g/L. However, tri-saccharide was the major (67%) in comparison to tetra (27%) and penta (6%) forms of GOS. Further, based on Michaelis-Menten kinetics, a six-step-eleven-parameter model was developed. The model incorporated enzyme inhibition and formation of glucose and galactose separately. Simulated results from developed model matched exceeding well with experimental results.
进行了将酶固定在微孔聚偏二氟乙烯 (PVDF) 膜上的实验研究，以便使用β-半乳糖苷酶将乳糖转化为半乳糖寡糖。然而，本工作是进行酶膜反应器研究的第一部分，旨在进行反应，然后通过膜分离从反应混合物中纯化半乳糖寡糖。三隔室电池的中间部分由两个固定化（酶）膜隔开，用于进料乳糖溶液；而相邻的隔室则装满蒸馏水。对反应混合物溶液进行了三、四和五聚体形式的 GOS 的分析。产物 GOS 的形成强烈依赖于初始乳糖浓度 (ILC) 的变化量。对于 ILC 从 50 至 200 g/L 的变化，总 GOS 形成从 7%增加到 28%。然而，与四聚体（27%）和五聚体（6%）形式的 GOS 相比，三聚体是主要的（67%）。此外，基于米氏动力学，开发了一个六步十一参数模型。该模型分别纳入了酶抑制和葡萄糖和半乳糖的形成。开发模型的模拟结果与实验结果非常吻合。
