Patent US139828A successfully refreshed from Google Patents.
Patent US4089746A successfully refreshed from Google Patents.
US4089746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for insolubilizing enzymes on chitosan
Assignee: United States Department of Agriculture
•
Filing: 1976-07-19
•
Granted: 1978-05-16
•
Expires: 1996-07-19
Abstract
Abstract Insolubilized but active enzymes are prepared by mixing an aqueous solution of the enzyme with an aqueous solution of chitosan and then adding a polyfunctional cross-linking agent to form a gel. The so-produced gel is reacted with a reducing agent to form a granular insolubilized enzyme, which has retained a substantial part of its original activity.
Inventors
- 👤 Merle S. Masri
- 👤 Virginia G. Randall
- 👤 William L. Stanley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:52
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/02; C12N11/10
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
88 words
A process for preparing an insoluble but active enzyme, which comprises (a) dissolving a soluble active enzyme in water, (b) dissolving chitosan in water, (c) mixing the aqueous solution of the enzyme with the aqueous solution of chitosan, (d) adding polyfunctional cross-linking agent to the mixture to produce a gel containing the enzyme, and (e) adding a reducing agent to the so-formed gel, said reducing agent being of sufficient reductive ability to produce a granular material from the gel but insufficient to lower the activity of the enzyme.
Claim 2
Dependent Claim
88 words
A process for preparing an insoluble but active enzyme, which comprises (a) dissolving a soluble active enzyme in water, (b) dissolving chitosan in water, (c) mixing the aqueous solution of the enzyme with the aqueous solution of chitosan, (d) adding polyfunctional cross-linking agent to the mixture to produce a gel containing the enzyme, and (e) adding a reducing agent to the so-formed gel, said reducing agent being of sufficient reductive ability to produce a granular material from the gel but insufficient to lower the activity of the enzyme.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the chitosan is dissolved in water at pH 7-7.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein the enzyme and chitosan are simultaneously dissolved in water.
Claim 5
Dependent Claim
26 words
The process of claim 1 wherein the polyfunctional cross-linking agent and the reducing agent are simultaneously added to the aqueous mixture of the enzyme and chitosan.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein the polyfunctional cross-linking agent is an aldehyde containing more than one aldehyde function.
Claim 7
Dependent Claim
19 words
The process of claim 1 wherein the polyfunctional cross-linking agent is an isocyanate containing more than one isocyanate function.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the reducing agent is sodium borohydride.
Claim 9
Dependent Claim
12 words
The process of claim 1 wherein the reducing agent is sodium cyanoborohydride.
Claim 10
Dependent Claim
12 words
The process of claim 1 wherein the enzyme is a sugar-hydrolyzing enzyme.
Claim 11
Dependent Claim
10 words
The process of claim 1 wherein the enzyme is invertase.
Claim 12
Dependent Claim
12 words
The process of claim 1 wherein the enzyme is a glucose-oxidizing enzyme.
Claim 13
Dependent Claim
26 words
An insoluble but active enzyme comprising a soluble enzyme and chitosan cross-linked with a polyfunctional agent into a gel and then granularized with a reducing agent.
Claim 14
Dependent Claim
26 words
An insoluble but active enzyme comprising a soluble enzyme and chitosan cross-linked with a polyfunctional agent into a gel and then granularized with a reducing agent.
Claim 15
Dependent Claim
12 words
The product of claim 12 wherein the enzyme is a sugar-hydrolyzing enzyme.
Claim 16
Dependent Claim
10 words
The product of claim 12 wherein the enzyme is invertase.
Claim 17
Dependent Claim
12 words
The product of claim 12 wherein the enzyme is a glucose-oxidizing enzyme.
Claim 18
Dependent Claim
19 words
The product of claim 12 wherein the polyfunctional cross-linking agent is an aldehyde containing more than one aldehyde function.
Claim 19
Dependent Claim
19 words
The product of claim 12 wherein the polyfunctional cross-linking agent is an isocyanate containing more than one isocyanate function.
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) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |