Method for microbially producing L-valine

摘要

The invention relates to a method for microbially producing L-valine in which the dihydroxy acid synthesis (ilvD) activity and/or the ilvD gene expression is intensified in a microorganism. Alternatively thereto or in combination therewith, the acetohydroxy acid synthesis (ilvBN) activity and isomeroreductase (ilvC) activity and/or the ilvBNC gene expression is intensified in a microorganism. According to the inventive method, microorganisms are preferably used in which the activity of at least one enzyme involved in a metabolic pathway which reduces the formation of L-valine is weakened or eliminated. Microorganisms having a defect mutation in the treonine dehydratase (ilvA) gene and/or having a defect mutation in one or more genes of the pantothenate synthesis are preferably used in the inventive method.