A process for the production of an L-amino acid wherein coryneform bacteria (e.g. Coryneform glutamicum) in which expression of the mqo gene coding for malate quinone oxidoreductase is attenuated are fermented to produce a desired amino acid, and the amino acid is concentrated in the medium or cells and isolated. Optionally, further genes in the biosynthetic pathway of the desired amino acid are enhanced, and/or metabolic pathways that reduce formation of the amino acid are suppressed.