Immobilized microbial cell composition for making L-aspartic acid
AssigneePurification Engineering, Inc.
InventorsLouis L. Wood, Gary J. Calton
Life of this patent
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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.
Claims11
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.
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.
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.
Dependencies are inferred from the claim text.