Abstract: A composition comprising immobilized cells obtained by applying a dispersion of cells and curable prepolymer material selected from the group consisting of polyazetidine prepolymers, carboxymethyl cellulose, polyurethane hydrogel prepolymers and polymethylene isocyanates. as a coating to a solid inert carrier and curing the prepolymer on the carrier at a temperature below the temperature at which enzyme activity of the cells is significantly reduced. The composition may be used to produce various materials such as L-aspartic acid, L-alanine, 6-Aminopenicillanic acid, high fructose corn syrup, prednisolone or phenylalanine.

Abstract: Phenylalanine is produced by contacting cells having transaminase activity with phenylpyruvic acid or phenylpyruvate in the presence of an amine donor. The cells may be ruptured or permeabilized to release their transaminase activity. Preferably, the cells are immobilized with a polyazetidine polymer. Preferred reaction conditions are an excess of amine donor in a ratio of at least 1.1:1 amine donor to phenylpyruvic acid or phenylpyruvate and a pH of 5-10 such as to convert at least 85% of the phenylpyruvic acid or phenylpyruvate to phenylalanine. Phenylalanine may also be produced from cinnamic acid using immobilized cells having phenylalamine ammonia lyase activity.

Abstract: Phenylalanine is prepared by contacting phenylpyruvic acid or phenylpyruvate with an enzyme having transaminase activity in the presence of an amine donor. The enyzme may be free or immobilized or in whole cells which may be free or immobilized. The enzyme is preferably contained by E. coli ATCC 11303. Yield of phenylalanine can be improved by removing oxaloacetate, produced during reaction of the enzyme, to drive the reaction to completion. Phenylalanine may also be produced from cinnamic acid using immobilized cells having phenylalanine ammonia lyase activity.

Abstract: Microbial cells are immobilized with a curable polyaziridine or polyfunctional aziridine prepolymer to obtain an insoluble, crosslinked polymer containing the cells. The microbial cells immobilized may be cells having L-aspartase or L-phenylalanine transaminase activity for the production of L-aspartic acid or L-phenylalanine. The polymer containing the cells may be formed as a coating on a solid inert carrier.

Abstract: A process is disclosed for preparing phenylalanine which comprises contacting phenylpyruvic acid or phenylpyruvate with immobilized whole cells having transaminase activity in the presence of an amine donor. The cells are preferably immobilized with a polyazetidine polymer. Ruptured or permeabilized cells, with the enzyme in the free or immobilized state, may also be used. The preparation of phenylalanine from cinnamic acid using immobilized cells having phenylalanine ammonia lyase activity is also disclosed.

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.