Productin of functional galacto-oligosccharides using transfer action of -galactosidase

与其他糖类和钙离子相比，乳糖的可溶性较低。在使用牛奶和奶酪乳清的食品制造和食品添加剂生产中，这些特性是缺点。为了增加双歧因子的功能并减少上述缺点，本研究旨在利用环状芽孢杆菌的-半乳糖苷酶1（-gal 1）和-半乳糖苷酶2 （-gal 2）有效地生产半乳糖低聚糖，这两种酶分别对乳糖的水解和乳糖的水解以及半乳糖低聚糖的合成具有高活性。为了达到这个目的，以下是具体的主题。化学修饰增强-gal - 1的低聚糖形成能力。-Gal 1和-Gal 2的固定化及其性质的阐明。固定化酶在连续反应过程中的稳定性。4 .采用质子流反应器或膜反应器长期连续生产低聚糖。固定化酶塔反应器的防污染、防清洗。用0.01 ~ 3%的戊二醛处理-Gal 1，酶上的氨基由0修饰到90%。随着改性次数的增加，形成含葡萄糖残基的聚合度为2 ~ 5的半乳糖低聚糖的能力增强，乳糖低聚糖的收率达到40%，氨基改性后的低聚糖收率达到90%。将-GAl 2或-GAl 1吸附在各种载体上，并通过戊二醛交联固定。在测试的支架中，Merckogel在活性和稳定性方面是最合适的。比活性越高，固定化酶越容易发生可逆失活。产生这种现象的原因是交联酶的三维网络中产生的低聚糖被包裹。在固定酶的PFR （15U/g）和膜反应器（Diaflo cell, UF-X50）中使用游离酶连续8天生产低聚糖，酶不灭活，20%乳糖的低聚糖产量保持在47.5%。从乳蛋白的吸附-解吸实验中，寻找出适合于防污染和清洁的载体。离子交换剂的电荷同污染物的标志是有效的。结果表明，采用大流量的支架可以抑制微生物的生长。少

Lactose is less soluble compared with other saccharides and tras calcium ion. These properties are the demerit in the food manufacturing and the food additive production using milk and chese whey. To add a function as bifidus factor as well as to diminish the above demerit, the preseht study aimed at the effective production of galacto-oligosaccharides using -galactosidase 1( -gal 1) and -galactosidase 2 ( -Gal 2) from Bacillus circulans which have high activity for hydrolysis of lactose and for hydrolysis of lactose and for synthesis of galactooligosaccharide, respectively. To accoplish the purpose, the following were the particular subjects.1.The enhancement of oligosaccharide formation ability of -gal 1 by chemical modification.2.Immobilization of -Gal 1 and 2 and elucidation of their properties.3.The stability of immobilyzed enzyme during continuous reaction.4.Long term continuous oligosuccharide production using either prug flow reactor or membrane reactor.5.Protection against con … More tamination and cleaning of immobilized enzyme column reactor.By treating the -Gal 1 with 0.01-3% glutaraldehyde, the amino group on the enzyme was modified from 0 to 90%. With increase in modification, increased the ability to form galacto-oligosaccharides of degree of polymerization two to five containing a glucose residue and yield of oligosaccharide from lactose reached to 40% with amino group modification 90%. Either -GAl 2 or -Gal 1 was adosorbed on to various suports and immobilized by glutaraldehyde crosslinking. Among the supports tested, Merckogel was most suitable with respect to activity and stability. however higher the specific activity, easer the immobilized enzyme deactivated reversibly. The reason for this phenomena was ascribed to the entrapment of oligosaccharides produced in the three dimensional network of crosslinked enzymes. Continuous oligosaccharide production was performed in PFR with immobilized enzyme on to merckogel SI-500(15U/g) and in membrane reactor(Diaflo cell, UF-X50) with free enzyme for 8 days without enzyme inactivation and the oligosaccharide yield from 20% lactose was maintained at 47.5%. From the adsorption-desorption experiments of milk protein, the support suitable with respect to the protection of contamination and cleaning was searched. Ion exchanger with the charge of same sign as contaminant was effective. The suggestion was obtained that the growth of micro-organism was reduced by usinglarge support with high flow rate. Less