Biotin (Bios II B , Vitamin H)—an Essential Growth Factor for Certain Staphylococci

Abstract
Several strains of Staph. aureus failed to grow on Gladstone''s chemically defined medium. Several substances demonstrated to be important for bacterial nutrition were added to this medium, without success; biotin, prepared by the procedure of Kogl and Tonnis from egg yolks permitted growth of S. aureus when added in a cone. of 0.0001 [gamma] per ml. A relationship exists between the amt. of growth and conc. of biotin suggesting a technique employing these strains for the bio-assay of biotin. Samples of Bios IIB and Vitamin H showed similar reaction.