A study has been made of the nutritional requirements of the pneumococcus. The relatively simple, chemically-defined medium composed of glutathione, thiochrome, nicotinamide, betaine, flavin, glucosamine, uracil, guanylic acid, xanthine, hypoxanthine, pantothenic acid, gelatin hydrolysate, amino acids, inorganic salts, and glucose which can support the growth of the Dochez NY 5 strain of hemolytic streptococcus (Rane and Subbarow, 1938;Subbarow and Rane, 1939) was found to be deficient for pneumococci. The addition of a highly-active, purified extract of liver provided conditions suitable for good growth of certain types of Pneumococcus. One fraction isolated from this liver extract demonstrated the growth value of a compound similar to, and replaceable by choline. Satisfactory growth was subsequently obtained in a medium consisting of gelatin hydrolysate, certain additional amino acids, inorganic salts, glucose, choline, nicotinic acid, pantothenic acid, flavin, and thioglycollic acid.In some cases a mixture of known amino acids could be substituted for the gelatin hydrolysate.
EXPERIMENTAL CULTURESPneumococci of Types I, II, V, VII and VIII have been used, one strain of each., These have been passed through mice five 1 These strains are used regularly at the Massachusetts Antitoxin and Vaccine Laboratory in mouse protection tests for the titration of potency of therapeutic antipneumococcic serum. We wish to thank our associates at the laboratory for their kind cooperation throughout this work.
