1988 Fiscal Year Final Research Report Summary
Productin of functional galacto-oligosccharides using transfer action of -galactosidase
| Project/Area Number |
62560126
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
製造化学・食品
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| Research Institution | Kyoto University |
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Principal Investigator |
MATSUNO Ryuichi Faculty of Agriculture, Kyoto University, 農学部, 教授 (30032931)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANISHI Kazuhiro Faculty of Engineering, Okayama University, 工学部, 教授 (90026584)
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| Project Period (FY) |
1987 – 1988
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| Keywords | -galactosidase / Galacto-oligosaccharides / Transfer action / Enzyme modification / Immobilized enzyme / Bacillus circulans / バイオリアクター |
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| Research Abstract |
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
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Research Products
(8 results)
