Vitamin Content of Ingredients of Microbiological Culture Media

Abstract

Information concerning the vitamin content of complex organic nitrogenous substances commonly used in culture media should be of general interest and of aid in the cultivation of microorganisms. For example, such information could be used in deciding whether a particular medium satisfies the growth requirements of a given organism. Through the kind cooperation of the Difco Laboratories, three or more representative samples of each of the commonly used ingredients of culture media such as peptone, tryptose, beef extract, yeast extract, etc., were obtained for vitamin assay. Three dehydrated culture media, brain-heart-infusion, heart-infusion and malt-extract-broth, and one sample each of Armour peptone, Liebig meat extract, natural asparagine and gelatin were also included. Altogether, 46 samples were assayed, quantitatively, for their content of 8 members of the vitamin B-complex, namely, thiamine, riboflavin, pantothenic acid, nicotinic acid, biotin, pyridoxine, folic acid, and p-aminobenzoic acid. The values obtained were compared with literature values of the amounts of the vitamins required for optimum growth of various bacteria, yeasts and fungi which are unable to synthesize these essential growth factors.