Pyridoxamine and the Synthesis of Amino Acids by Lactobacilli

Abstract

The requirements of Lactobacillus delbruckii LD5, L. casei and L. arabinosus 17-5, for lysine, threonine and alanine, were eliminated by pyridoxamine, but this was not true for S. lactis R. These 3 amino acids were synthesized by the lactobacilli when grown in media containing pyridoxamine. L. arabinosus is unlike the other 2 lactobacilli since it does not require added pyridoxine to develop in an otherwise complete medium. This organism will not grow in media lacking lysine, threonine and alanine unless pyridoxamine is added.