Fermentative Production of L-Glutamic-γ-Semialdehyde and Its Chemical Conversion into L-Tryptophan

Abstract

Proline auxotrophs, which were induced from an i -prolific-producing strain of Brevibacterium flavum by indirect suppression mutation, accumulated L-glutamic-γ-semialdehyde (GSA) in the fermentative broth. The addition of sulfite salts to the culture medium, when bacteria were exponentially growing, improved the accumulation of GSA from 2.3 to a maximum of 13.2 mg/ml. The direct use of GSA in the fermentative broth for the chemical synthesis of L-tryptophan was studied. The yield of L-tryptophan was 48% on the basis of GSA in the reaction mixture.