Microbial deracemization of α-amino acids

Dai Ichiro Kato, Kenji Miyamoto, Hiromichi Ohta

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


We screened new microorganisms having deracemization activity of α-amino acids and isolated some active strains. Whole cells of these strains were capable of inverting the chirality of 4-chlorophenylalanine from d- to l-configuration. In particular, Nocardia diaphanozonaria JCM 3208 exhibits the deracemization activity towards wide variety of α-amino acids, such as phenylglycine and 2-aminoheptanoic acid. Examination of the time course of the reaction revealed that α-keto acid was produced as the key intermediate. In addition, mechanistic studies using cell-free extract suggested that deracemization process is realized by two enzymatic reactions; d-stereoselective oxidative deamination reaction and l-selective transamination reaction. Finally, we could establish the reaction conditions utilizing the cell-free system to proceed the deracemization of phenylalanine, which was degraded when the whole cells were used as the biocatalyst.

Original languageEnglish
Pages (from-to)157-165
Number of pages9
JournalJournal of Molecular Catalysis B: Enzymatic
Issue number4
Publication statusPublished - 2005 Feb 1


  • Enantioselective inversion of configuration
  • Microbial deracemization
  • d-Phenylalanine degrading microorganisms
  • α-Amino acids

ASJC Scopus subject areas

  • Catalysis
  • Bioengineering
  • Biochemistry
  • Process Chemistry and Technology


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