Microbial production of essential amino acid with Corynebacterium glutamicum mutants.

Amino acids produced by microbial process are generally L-forms. The stereospecificity of the amino acids produced by fermentation makes the process advantageous compared with synthetic process. Microorganisms employed in microbial process for amino acid production are divided into 4 classes; wild-type strain, auxotrophic mutant, regulatory mutant and auxotrophic regulatory mutant. Using such mutants of Corynebacterium glutamicum, all the essential amino acids but L-methionine are now being produced by "direct fermentation" from cheap carbon sources such as carbohydrate materials or acetic acid.