Can Azotobacter chroococcum Synthesize Vitamin D?

Abstract

A. c. was cultured on synthetic media consisting of inorganic salts and mannitol and tested for vitamin D and its precursor by feeding to rats. It was concluded from the line test, the P content of the blood, and the composition of the bone ash that Azotobacter chroococcum synthesizes from this simple medium the precursor of vitamin D, which is readily transformed into vitamin D by irradiation. This finding places this microorganism along with Clostridium butyricum, Staphylococcus albus, and the higher plants in being able to synthesize ergosterol but unable to synthesize vitamin D. It differentiates A. c. from Mycobacterium tuberculosis, Bacterium coli, and Corynebacterium in that the latter contain neither sterol nor vitamin D.