摘要:
In a process for the production of a D-.alpha.-amino acid, in which an N-carbamyl-D-.alpha.-amino acid corresponding to the general formula: ##STR1## wherein R represents phenyl, hydroxy-substituted phenyl, substituted or unsubstituted alkyl, or thienyl, is converted by a microbial enzyme in an aqueous medium to a D-.alpha.-amino acid corresponding to the general formula: ##STR2## wherein R is the same as defined above, decarbamylase produced by a microorganism of the genus Comamonas, Blastobacter, Alcaligenes, Sporosarcina, Rhizobium, Bradyrhizobium or Arthrobacter is used as the enzyme converting the N-carbamyl-D-.alpha.-amino acid to the D-.alpha.-amino acid.The conversion of the N-carbamyl-D-.alpha.-amino acids to the D-.alpha.-amino acids is carried out in a neutral to alkaline pH range.
摘要:
In a process for the production of a D-.alpha.-amino acid, in which an N-carbamyl-D-.alpha.-amino acid corresponding to the general formula: ##STR1## wherein R represents phenyl, hydroxy-substituted phenyl, substituted or unsubstituted alkyl, or thienyl, is converted by a microbial enzyme in an aqueous medium to a D-.alpha.-amino acid corresponding to the general formula: ##STR2## wherein R is the same as defined above, decarbamylase produced by a microorganism of the genus Comamonas, Blastobacter, Alcaligenes, Sporosarcina, Rhizobium, Bradyrhizobium or Arthrobacter is used as the enzyme converting the N-carbamyl-D-.alpha.-amino acid to the D-.alpha.-amino acid.The conversion of the N-carbamyl-D-.alpha.-amino acids to the D-.alpha.-amino acids is carried out in a neutral to alkaline pH range.
摘要:
Decarbamylases are provided capable of producing D-.alpha.-amino acids by hydrolysis of N-carbamyl-D-.alpha.-amino acids. A source of the decarbamylases is recombinant microorganisms produced by gene manipulation methods. Decarbamylases having improved thermostability can be obtained in which amino acids at a thermostability-related site of a natural decarbamylase have been replaced with other amino acids by mutating a DNA fragment encoding the natural decarbamylase. Recombinant DNA is obtained from a vector DNA and a DNA fragment encoding a natural decarbamylase where the nucleic acid sequence encoding an amino acid at a thermostability-related site is replaced with a nucleic acid sequence encoding another amino acid. The recombinant DNA is used to produce transformants that produce thermostable decarbamylases. The decarbamylases may be immobilized in purified, partially-purified or crude form or in the form of decarbamylase-containing microbial cells on a support such as a polymer having ion exchange groups or covalent bonding groups. The presence of an antioxidant such as dithiothreitol results in an immobilized decarbamylase preparation that can be repeatedly used 30 times or more.
摘要:
The present invention is directed to a gene which is related to a D-N-carbamoyl-.alpha.-amino acid amidohydrolase which is an enzyme capable of converting D-N-carbamoyl-.alpha.-amino acids into D-.alpha.-amino acids; a recombinant plasmid in which a DNA fragment containing the gene is incorporated into a vector; a microorganism belonging to the genus Escherichia, Pseudomonas, Flavobacterium, Bacillus, Serratia, Corynebacterium, or Brevibacterium, which is transformed by incorporating the recombinant plasmid thereinto; a process for the production of D-N-carbamoyl-.alpha.-amino acid amidohydrolases, comprising the steps of cultivating the transformed microorganism and collecting the desired product therefrom; a D-N-carbamoyl-.alpha.-amino acid amidohydrolase obtained by the method; and a process for the production of D-.alpha.-amino acids with the aid of an action of the enzyme. The D-N-carbamoyl-.alpha.-amino acid amidohydrolase can be fixed on a support for immobilization and used as an immobilized enzyme.
摘要:
A process for the efficient production of a D-amino acid from the corresponding DL-5-substituted hydantoin by one-step reaction which comprises using a composite immobilized enzyme at a pH about neutrality, said composite immobilized enzyme being obtained by immobilizing a hydantoinase having its optimal pH within an alkaline range and a D-N-carbamyl-.alpha.-amino acid amidohydrolase having its optimal pH about neutrality in a coexisting state on an immobilizing support, simultaneously, is disclosed.
摘要:
A DNA fragment coding for a decarbamylase protein improved in thermostability as the result of replacement of at least one base of a DNA fragment coding for a decarbamylase protein derived from a microorganism with another base and the resultant replacement of at least one of the corresponding amino acids, and its production process; a vector containing the DNA fragment; a transformant obtained by transformation with the vector; as well as a decarbamylase improved in thermostability and its production process. Also disclosed is a process for producing a D-.alpha.-amino acid, which comprises converting an N-carbamoyl-D-.alpha.-amino acid into the corresponding D-.alpha.-amino acid in an aqueous medium by the action of a decarbamylase having a thermostable temperature of 65.degree. C. or higher; and collecting the D-.alpha.-amino acid produced.
摘要:
The present invention is directed to a gene which is related to a D-N-carbamoyl-.alpha.-amino acid amidohydrolase which is an enzyme capable of converting D-N-carbamoyl-.alpha.-amino acids into D-.alpha.-amino acids; a recombinant plasmid in which a DNA fragment containing the gene is incorporated into a vector; a microorganism belonging to the genus Escherichia, Pseudomonas, Flavobacterium, Bacillus, Serratia, Corynebacterium, or Brevibacterium, which is transformed by incorporating the recombinant plasmid thereinto; a process for the production of D-N-carbamoyl-.alpha.-amino acid amidohydrolases, comprising the steps of cultivating the transformed microorganism and collecting the desired product therefrom; a D-N-carbamoyl-.alpha.-amino acid amidohydrolase obtained by the method; and a process for the production of D-.alpha.-amino acids with the aid of an action of the enzyme.The D-N-carbamoyl-.alpha.-amino acid amidohydrolase can be fixed on a support for immobilization and used as an immobilized enzyme.
摘要:
The present invention relates to novel D-amino acid oxidase isolated and purified from Candida intermedia, a gene encoding the D-amino acid oxidase, a recombinant plasmid containing the gene, and a transformant into which the D-amino acid oxidase gene has been introduced, as well as a production method of D-amino acid oxidase including culturing the transformant. Moreover, the present invention relates to a production method of L-amino acids, 2-oxo acids or cyclic imines, which include reacting racemic amino acids with the D-amino acid oxidase, more preferably, a production method of L-amino acids, which includes reacting racemic amino acid with the D-amino acid oxidase, amino acid dehydrogenase and an enzyme having a coenzyme-regenerating activity. According to the present invention, L-amino acids, 2-oxo acids or cyclic imines can be produced with good efficiency in an industrial scale.
摘要:
It is an object of the present invention to provide a novel amidase that is useful for production of an optically active amino acid, and in particular, a D-amino acid, and a production method thereof.The present invention relates to a novel D-amidase isolated and purified from the Arthrobacter sp. KNK1101J, a gene encoding the above amidase, a recombinant plasmid comprising the above gene, and a transformant into which the above amidase gene has been introduced. In addition, the present invention also relates to a method for producing the amidase, comprising culturing the Arthrobacter sp. KNK1101J or the above transformant, and collecting the above amidase.
摘要:
The present invention relates to novel D-amino acid oxidase isolated and purified from Candida intermedia, a gene encoding the D-amino acid oxidase, a recombinant plasmid containing the gene, and a transformant into which the D-amino acid oxidase gene has been introduced, as well as a production method of D-amino acid oxidase including culturing the transformant. Moreover, the present invention relates to a production method of L-amino acids, 2-oxo acids or cyclic imines, which include reacting racemic amino acids with the D-amino acid oxidase, more preferably, a production method of L-amino acids, which includes reacting racemic amino acid with the D-amino acid oxidase, amino acid dehydrogenase and an enzyme having a coenzyme-regenerating activity. According to the present invention, L-amino acids, 2-oxo acids or cyclic imines can be produced with good efficiency in an industrial scale.