Observations on a growth factor for Leuconostoc citrovorum

Abstract

Liver extracts and fermentation liquors from Streptomyces griseus contain a growth factor for L. citrovorum. A microbiological tube test was developed for this factor, and an arbitrary unit has been defined. The factor is not identical with vit. B12 or vit. B13. Concentrates of the factor derived from liver or from fermentation liquors, and containing vit. B12 also, were purified approx. 10 times, and the vit. B12 was removed, by adsorption on the anion-exchange resin IRA 400, elution with NaCl soln., adsorption of the alkaline eluate on the cation-exchange resin IRC50 and elution with water. The factor appears to have no activity against pernicious anemia, but possesses leucocyte-stimulating activity.