US4094743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Enzymes immobilized on chitosan
Assignee: Nestec SA
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Filing: 1976-04-01
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Granted: 1978-06-13
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Expires: 1996-04-01
Abstract
Abstract An enzymatically active product insoluble in aqueous medium is prepared by treating chitosan as an inert support with a dialdehyde, after which an enzyme is fixed to the support thus treated. The chitosan may be in powder-form or in flake-form, for example obtained by fragmenting a film of anhydrous chitosan. The enzymatically active product insoluble in aqueous medium may be treated with a compound containing an amino group and/or with a reducing reagent. The product may be freeze dried optionally in the presence of twice its weight of mannitol.
Inventors
- 👤 Jean-Louis Leuba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:23
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0024; C08B37/0027; C08B37/003; C12; C12N; C12N11/00; C12N11/02; C12N11/10
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
45 words
A process for the preparation of an enzymatically active product insoluble in aqueous medium, comprising treating chitosan as an insoluble inert support with a dialdehyde to provide an activated chitosan support and thereafter fixing an enzyme containing free amino groups to said activated chitosan support.
Claim 2
Dependent Claim
45 words
A process for the preparation of an enzymatically active product insoluble in aqueous medium, comprising treating chitosan as an insoluble inert support with a dialdehyde to provide an activated chitosan support and thereafter fixing an enzyme containing free amino groups to said activated chitosan support.
Claim 3
Dependent Claim
12 words
A process according to claim 1, in which said dialdehyde is glutaraldehyde.
Claim 4
Dependent Claim
14 words
A process according to claim 1, in which said chitosan is a powder-form chitosan.
Claim 5
Dependent Claim
14 words
A process according to claim 1, in which said chitosan is a flake-form chitosan.
Claim 6
Dependent Claim
22 words
A process according to claim 4, in which said chitosan is a flake-form chitosan obtained by fragmenting a film of anhydrous chitosan.
Claim 7
Dependent Claim
25 words
A process according to claim 1, in which said enzymatically active product insoluble in aqueous medium is treated with a compound containing an amino group.
Claim 8
Dependent Claim
22 words
A process according to claim 1, in which said enzymatically active product insoluble in aqueous medium is treated with a reducing reagent.
Claim 9
Dependent Claim
30 words
A process according to claim 1, in which said enzymatically active product insoluble in aqueous medium is treated with a compound containing an amino group and with a reducing reagent.
Claim 10
Dependent Claim
16 words
A process according to claim 6, in which said compound containing an amino group is lysine.
Claim 11
Dependent Claim
14 words
A process according to claim 7, in which said reducing reactant is sodium borohydride.
Claim 12
Dependent Claim
23 words
A process according to claim 8, in which said compound containing an amino group is lysine and said reducing reagent is sodium borohydride.
Claim 13
Dependent Claim
18 words
A process according to claim 1, in which said enzymatically active product insoluble in aqueous medium is freeze-dried.
Claim 14
Dependent Claim
27 words
A process according to claim 12, in which said enzymatically active product insoluble in aqueous medium is freeze-dried in the presence of twice its weight of mannitol.
Claim 15
Dependent Claim
22 words
A process according to claim 1, in which said chitosan and said dialdehyde are reacted at a pH-value from 6 to 8.
Claim 16
Dependent Claim
23 words
A process according to claim 1, in which said chitosan and said dialdehyde are reacted at a temperature from 2° to 35° C.
Claim 17
Dependent Claim
19 words
A process according to claim 1, in which said enzyme is fixed at a pH-value from 2 to 11.
Claim 18
Dependent Claim
27 words
A process according to claim 1, in which said enzyme is fixed at a temperature from 2° C to the temperature at which said enzyme is inactivated.
Claim 19
Dependent Claim
18 words
An enzymatically active product insoluble in aqueous medium when prepared by a process as claimed in claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |