Biosynthesis of pyridoxine: Origin of the nitrogen atom of pyridoxine in microorganisms

The amide nitrogen atom of glutamine was incorporated into pyridoxine in fo ur eukaryotes, Emericella nidulans, Mucor racemosus, Neurospora crassa and Saccharomyces cerevisiae. and two prokaryotes, Staphylococcus aureus and Ba cillus subtilis, but not in the following prokaryotes, Pseudomonas putida, Enterobacter aerogenes and Escherichia coli. On the other hand, the nitroge n atom of glutamate was incorporated into pyridoxine in P. putida, E. aerog enes and E. coli, but not in S. aureus and B. subtilis. These results sugge st that there are at least two different biosynthetic routes for pyridoxine and the difference does not depend on prokaryotes and eukaryotes.