Nippon Shokubai Co., Ltd.

Shinzo Yasuda

Masaharu Mukouyama

Satomi Komatsuzaki

This invention relates to a method for producing L-aspartic acid comprising treating an ammonium fumarate solution with aspartase to generate an ammonium L-aspartate solution; adding fumaric acid to the solution; and then crystallizing L-aspartic acid from the solution, wherein fumaric acid is added to the ammonium L-aspartate solution after the solution has been heated to 50 to 130&deg; C. in an amount 0.4 to 0.8 times the total amount of fumarate and the L-aspartate contained therein in terms of mole, and the resultant mixture is once turned into a homogeneous solution by applying thereto a shearing force, and then L-aspartic acid is deposited therefrom, or wherein the solution is cooled at a rate of 0.1-5&deg; C./min from the temperature at which fumaric acid is added thereto to the temperature at which crystallized L-aspartic acid is separated therefrom, to thereby deposit L-aspartic acid.

Methods for producing L-aspartic acid

A process for producing a polysuccinimide (co)polymer derivative which permits the reaction of a polysuccinimide (co)polymer with a Lewis base in a wide temperature range (90&deg; to 300&deg; C.) without using a pH-adjusting agent is provided. The process for producing a polysuccinimide (co)polymer derivative of this invention comprises reacting a polysuccinimide (co)polymer with a Lewis base by heating in the presence of a solvent having a low boiling point and high relative permittivity.

Polysuccinimide(CO) polymer derivate and process for production thereof

A method capable of molding by a simple procedure such a polymer as a polysuccinimide based (co)polymer or a protein whose glass transition temperature is very close to the decomposition temperature is provided. The method for the molding of a polymer contemplated by this invention comprises heating and melting a polymer whose glass transition temperature is very close to the decomposition temperature in the presence of a solvent having a low boiling point and a high dielectric constant ratio and then molding the resultant molten product.

Method for molding of polymer

A polyaspartic acid is obtained from an amino acid having aspartic acid as an essential component thereof without entailing formation of a bulk substance. A method for the production of polyaspartic acid is described which includes heating an amino acid having aspartic acid as an essential component thereof in the presence of water. A novel polyaspartic acid obtained by this method of production is described.

Polyaspartic acid

A succinimide polymer is produced by thermally polymerizing an ammonium salt of aspartic acid in the presence of an acid catalyst such as a boric acid catalyst. Another amino acid may be added for copolymerizing with the ammonium salt of aspartic acid. Ammonia liberated during the production of a succinimide polymer can be collected in a fumaric acid suspension, an acidic fumaric acid solution, a maleic acid solution or an acidic maleic acid solution, and the resultant liquid reacted with an enzyme which may be immobilized to produce L-aspartic acid. An aspartic acid polymer is produced by hydrolyzing the succinimide polymer with a basic substance.

Methods for producing a succinimide polymer, an aspartic acid polymer and L-aspartic acid

The present invention provides a gene coding for maleate isomerase excellent in stability, a recombinant vector having the gene, and a transformant transformed with the recombinant vector. According to the present invention, maleate isomerase excellent in stability can be produced efficiently in a large amount.

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Ushiku, Japan

Shinzo Yasuda