Tryptophan Production by Transport Mutants ofCorynebacterium glutamicum

Abstract

Three mutants with lower levels of tryptophan uptake were derived from a tryptophan-producing strain of Corynebacterium glutamicum. They all showed improved production kinetics at the latter half of fermentation and accumulated 10 to 20% more tryptophan than their parent. These results indicate that prevention of amino acid uptake can be a useful strategy to bypass remaining regulatory steps and thereby to increase the yield and productivity in amino acid high-producing strains.