Enzymatic Production of L-Tryptophan from L- and DL-5-Indolyl-methylhydantoin by Newly Isolated Bacterium

Abstract

Bacteria which can hydrolyze DL-5-indolylmethylhydantoin to L-tryptophan were isolated from various soils. The DL-5-indolylmethylhydantoin-hydrolyzing enzymes were found to be inducible and intracellular. With intact cells, 50mg/ml as wet base, of newly isolated bacterial strain T-523, 10mg/ml of DL-5-indolylmethylhydantoin dissapeared and 7.4mg/ml of L-tryptophan in a molar yield of 82% was produced after 35 hr incubation. Tryptophan produced was confirmed to be L-form regardless of the stereoisomer of the substrates used. A mechanism of asymmetric hydrolysis of DL-5-indolylmethylhydantoin was discussed.