Synthesis of Pyridoxine by a Pyridoxal Auxotroph of Escherichia coli

Abstract

A pyridoxal auxotroph of E. coli B produced pyridoxol and pyridoxol 5[image]-phos-phate during starvation for pyridoxal. The identification of these compounds was made both by bioassay and by ion-exchange chromatography. Pyridoxol 5[image]-phosphate oxidase activity was absent in extracts of the auxotroph. The rate of synthesis of total pyridoxine by a pyridoxal-starved culture of this auxotroph was 6.0 x 10-6 moles per mg per hr. Cellular content of pyridoxine was constant at 4.0 x 10-10 moles/mg.