[Nature of factors stimulating cobalamin production by Achromobacter cobalamini]

The object of this work was to study the nature of factors contained in molasses and maize extract and stimulating cobalaminogenesis in Achromobacter cobalamini. The activity of substrate fractions was analyzed to show that the stimulating substance was precipitated on the cation exchanger and eluted from it with HCl. The factor was found to be an organic nitrogen base readily soluble in water and ethanol but insoluble in ether, chloroform and methanol. It was stable upon heating in concentrated HCl. Betaine in the composition of molasses and choline in the composition of maize extract had similar properties. Their addition to the growth medium produced the same effect as that of molasses and maize extract. It is concluded therefore that cobalaminogenesis is stimulated in A. cobalamini by betaine in molasses and by choline in maize extract.