text: The commercial production of amino acids usually relies on mutant bacteria that overproduce individual amino acids using glucose as a carbon source.  Some amino acids are produced by enzymatic conversions of synthetic intermediates. 2-Aminothiazoline-4-carboxylic acid is an intermediate in the industrial synthesis of L-cysteine for example. Aspartic acid is produced by the addition of ammonia to fumarate using a lyase.