Characterization of pyridoxine auxotrophs of Escherichia coli: P1 transduction.

Pyridoxine mutants of Escherichia coli B, previously divided into a minimum of six groups by cross-feeding tests, were characterized by transduction studies performed with phage P1bt. The results of these studies allowed division of pyridoxine mutants into five unlinked groups and set the minimum number of enzymes between pyridoxal phosphate and a metabolite common to other pathways at six or seven, with the probable maximum at ten. One group was shown to be linked to thr, leu, and pyrA.