Amino acid fermentation has grown into a global industry. Market development has been particularly dynamic for the flavor-enhancer glutamate and animal feed amino acids: L ? lysine, DL ? methionine, L ? threonine, and L ? tryptophan. These amino acids are manufactured using high performance Corynebacterium glutamicum. Production strains have been traditionally constructed by repeating random mutation and selection. This classical method has generated a variety of mutation, such as auxotrophs, analog-resistant mutants and transport mutants. The complete genome sequence of the wild-type strain of C. glutamicum has been established and analysed to improve the understending of the molecular biology and physiology of this organism. A novel methodology that merges genomics with classical strains improvement has been developed and applied for the reconstruction of classicaly derived production strains. In addition, modern technologies such as metabolic flux analysis and metabolic control analysis have enabled quantification of carbon fluxes. The fundamental information obtained has been the basis for further strain improvement.