abstract:Auxotrophy (Gr. αὐξάνω "to increase"; τροφή "nourishment") is the inability of an organism to synthesize a particular organic compound required for its growth (as defined by IUPAC).
Methioninesynthaseis a keyenzymein homocysteinemetabolism. The defectsof methionine synthase activitycouldresult inhyperhomocysteinemiaandmethionineauxotrophy.