The Nutritional Requirements of a Strain of Type III Pneumococcus

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Abstract
The factors necessary for the growth of Type III (CHA) pneumococcus were found to be a casein-acid-hydrolysate, cystine, KH2PO4, MgSO4, nicotinic acid, pantothenic acid, bio-tin, choline, glucose, and ascorbic acid. Addition of creatine, asparagine or thiamine accelerated growth but was not essential. Cystine could be replaced with cysteine or glutathione but not with methionine, homocys-teine or thioglycolic acid. Ethanol-amine in 10 times the molar conc. of choline could replace choline. Growth in the presence of ethanolamine occurred in characteristic long chains. A new semi-synthetic medium for Type III pneumococcus has the following composition: a basal medium of vitamine-free casein hydrolysate, 0.5 gm. N; l-cystine, 0.025 gm.; KH2PO4, 5 gm.; MgSO4 7H2O, 0.4 gm.; dist. water to make 800 ml. The conc. per ml. medium should be: choline chloride, 5 [gamma]; Ca panto-thenate, 1 [gamma]; nicotinic acid, 1 [gamma]; biotin (crystalline), 0.002 [gamma]; thiamine, 2 [gamma]; creatine, 5 [gamma]; asparagine, 1 [gamma]; ascorbic acid, 300 [gamma]; glucose (auto-claved separately and added to sterile medium aseptically), 5[gamma]. In this medium the pneumococci were found not only to survive and multiply from very small inocula but to maintain their virulence and type specificity after repeated subcultures.