Miwon Co., Ltd.

Daesang Corporation

Bun Sam Lim

Min S Han

Chan Hee Won

See Young Yu

Jin Man Cho

Sae Bae Lee

Chung Park

Jong Soo Kim

Min Hyung Kim

In Suk Choi

Dae K Joo

Sung Sook Choi

Kyung Eun Choi

Man J In

Il Hyun

Kwang H Kim

Seung T Lee

Hwa Jung Dho

Gae C Lee

Heon Yong Eohm

Disclosed is a method of crystallizing .alpha.-L-aspartyl-L-phenylalanine methyl ester, which is a sweetening agent substituting sugar and commonly referred to as aspartame. An aspartame solution is sprayed and droplets of the solution fall downward. Cold airflow is blown to the falling droplets of the aspartame solution to cool them. The aspartame dissolved in the droplets crystallizes, and the slurry including the aspartame crystals and the remaining solution is collected for further processes. Also disclosed is a crystallizer for cooling crystallizing the aspartame solution with this method. The crystallizer has an atomizer for spraying the aspartame solution supplied thereto and an air inlet and an air outlet. The cold air is blown into the crystallizer through the air inlet, cools the droplets of the aspartame solution, and is discharged through air outlet.

Crystallization of .alpha.-L-aspartyl-L-phenylalanine methyl ester

Disclosed is a method of crystallizing .alpha.-L-aspartyl-L-phenylalanine methyl ester, which is a sweetening agent substituting sugar and commonly referred to as aspartame. An aspartame solution is gradually cooled by heat exchanging with a coolant passing by with each other in the opposite direction. This enables that the heat-exchange between the aspartame solution and the coolant occurs at small and almost constant temperature difference. The cooling crystallization with such small temperature difference provides coarse and uniform aspartame crystals. Also, the aspartame solution is forcedly stirred such that crystals and crystal lumps formed are not re-dissolved or broken down. The forced stir of the solution makes the crystals and the lumps be suspended in the solution, which prevents formation of scales on any surfaces.

Crystallization of alpha-L-aspartyl-L-phenylalanine methyl esther

Disclosed is a method of cooling and crystallizing .alpha.-L-aspartyl-L-phenylalanine methyl ester, which is a sweetening agent, commonly referred to as aspartame. An aspartame solution is cooled such that the solution is flown while being continuously in thermal contact with a coolant. As the cooling of the aspartame solution by the thermal contact with the coolant proceeds, the temperature difference between the aspartame solution and the coolant remains substantially constant. The coolant flows in the opposite direction as the aspartame solution flows and cools an upstream part of the aspartame solution as the coolant flows downstream.

This invention relates to an improvement in a method for manufacturing dipeptides by coupling N-blocked aspartic acid and a phenylalanine lower alkyl ester in a medium containing a water-miscible organic solvent mixture in the presence of an immobilized metallo-protease so that a continuous reaction is established with stable enzyme activity.

Process for preparing dipeptides

An immobilized fructosyltransferase enzyme is prepared by providing a porous or macroporous anion exchange resin having at least 1.0 m.sup.2 /g of internal surface, at least 0.1 ml/g of total porous volume, a spherical radius of 20-2,000 angstroms, and a nominal ion-exchange capacity of at least 1.0 meq./g of wet resin, adding to the ion-exchange resin a solution of fructosyltransferase enzyme derived from a microorganism of the genus Aureobasidium, Aspergillus, Fusarium, or Gloeosporium at a pH value of about 3-8, filtering and wind-drying the absorbed resin, and storing it in a cool place. A bifunctional cross-linking agent may be present in the solution of fructosyltransferase enzyme.

Immobilization of fructosyltransferase on a basic, porous anion-exchange

An E. Coli which can produce phenylalanine and which has an optimum phenylalanine production capability at a temperature of 30.degree. to 35.degree. C., and a process for preparing L-phenylalanine by use of the novel E. coli MWPEC 12-45 (ATCC 67460).

Method for production of L-phenylalanine by recombinant E. coli ATCC

An E. coli which can produce phenylalanine and which has an optimum phenylalanine production capability at a temperature between 30.degree. C. and 35.degree. C., and a process for preparing L-phenylalanine by use of the novel E. coli. The novel E. coli is designated MWPEC 13-60 (ATCC 67459).

Method for production of L-phenylalanine by recombinant E. coli

A process for purification and recovery of phenylalanine from a microbial fermentation broth containing phenylalanine which comprises providing a zinc salt of phenylalanine at a pH of 7-9, adding acid at a pH of 4-7, and separating precipitated phenylalanine.

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Seoul, South Korea

Bun Sam Lim