US4436813A
Expired / Lapsed
US
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Immobilized microbial cell composition for making L-aspartic acid
Assignee: Rhodia Chimie SAS
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Filing: 1982-03-16
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Granted: 1984-03-13
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Expires: 2002-03-16
Abstract
Abstract Microbial cells having L-aspartase activity are immobilized for producing L-aspartic acid. The cells are immobilized by mixing the cells with a curable prepolymer material and curing the prepolymer material to form a crosslinked polymer. Suitable prepolymer materials are polyazetidine prepolymers, carboxymethyl cellulose which can be crosslinked with polyvalent ions, polyurethane hydrogel prepolymers and polymethylene isocyanates. A preferred prepolymer material is polyazetidine prepolymer. The polymer may be formed as a coating on a solid inert carrier.
Inventors
- 👤 Louis L. Wood
- 👤 Gary J. Calton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:53
CPC Classifications
C; C12; C12P; C12P13/00; C12P13/04; C12P13/20; C12N; C12N11/00; C12N11/02; C12N11/08; C12N11/089; C12N11/098; C12P13/06; C12P13/22; C12P13/222; C12P19/00; C12P19/24; C12P33/00; C12P33/02; C12P37/00; C12P37/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
71 words
A process for preparing L-aspartic acid which comprises contacting ammonium fumarate with an immobilized microbial cell composition comprising cells containing L-aspartase activity immobilized by means of an insoluble, crosslinked polymer obtained by curing a curable polyazetidine prepolymer, said prepolymer being cured at a temperature below the temperature at which the L-aspartase activity of the microbial cells is significantly reduced, the cell/crosslinked polymer composition constituting a coating on a solid inert carrier.
Claim 2
Dependent Claim
71 words
A process for preparing L-aspartic acid which comprises contacting ammonium fumarate with an immobilized microbial cell composition comprising cells containing L-aspartase activity immobilized by means of an insoluble, crosslinked polymer obtained by curing a curable polyazetidine prepolymer, said prepolymer being cured at a temperature below the temperature at which the L-aspartase activity of the microbial cells is significantly reduced, the cell/crosslinked polymer composition constituting a coating on a solid inert carrier.
Claim 3
Dependent Claim
17 words
A process according to claim 1 wherein the cells are whole cells of E. coli ATCC 11303.
Claim 4
Dependent Claim
15 words
A process according to claim 2 wherein the carrier comprises beads or other particulate material.
Claim 5
Dependent Claim
62 words
A composition comprising immobilized E. coli cells having L-aspartase activity, the cells being immobilized by means of an insoluble, crosslinked polymer obtained by curing a curable polyazetidine prepolymer, said prepolymer being cured at a temperature below the temperature at which the L-aspartase activity of the microbial cells is significantly reduced, the cell/crosslinked polymer composition constituting a coating on a solid inert carrier.
Claim 6
Dependent Claim
62 words
A composition comprising immobilized E. coli cells having L-aspartase activity, the cells being immobilized by means of an insoluble, crosslinked polymer obtained by curing a curable polyazetidine prepolymer, said prepolymer being cured at a temperature below the temperature at which the L-aspartase activity of the microbial cells is significantly reduced, the cell/crosslinked polymer composition constituting a coating on a solid inert carrier.
Claim 7
Dependent Claim
13 words
A composition according to claim 4 wherein the carrier is a particulate support.
Claim 8
Dependent Claim
70 words
A process for preparing an immobilized microbial cell composition which comprises mixing together an aqueous dispersion of cells containing L-aspartase activity and a polyazetidine prepolymer which is capable of being cured into a crosslinked polymer and curing the polyazetidine prepolymer in said mixture at a temperature below the temperature at which the L-aspartase activity of the cells is significantly reduced, the cells being thereby immobilized by the cured polyazetidine polymer.
Claim 9
Dependent Claim
70 words
A process for preparing an immobilized microbial cell composition which comprises mixing together an aqueous dispersion of cells containing L-aspartase activity and a polyazetidine prepolymer which is capable of being cured into a crosslinked polymer and curing the polyazetidine prepolymer in said mixture at a temperature below the temperature at which the L-aspartase activity of the cells is significantly reduced, the cells being thereby immobilized by the cured polyazetidine polymer.
Claim 10
Dependent Claim
21 words
A composition obtained by the process of claim 6 comprising cells having L-aspartase activity immobilized by said cured, crosslinked polyazetidine polymer.
Claim 11
Dependent Claim
13 words
A composition according to claim 7 wherein the cells are E. coli cells.
Claim 12
Dependent Claim
18 words
A composition according to claim 7 and comprising a coating of the immobilized cells on a particulate support.
Claim 13
Dependent Claim
25 words
The process of claim 6 wherein the polazetidine prepolymer in the mixture is cured after application of the mixture as a coating to a carrier.
Claim 14
Dependent Claim
10 words
The process of claim 10 wherein the coating is dried.
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) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |