Studies on Bacterial Nutrition: A Comparative Study of the Growth-Promoting Properties of Various Substances

The Production of Staphylococcus Enterotoxin and Alpha Hemolysin in a Simplified Medium

“…A number of investigators, including Gladstone (1938), Ramon et al (1938) and Koser et al (1938) have developed synthetic or simplified media for the purpose of producing staphylococcus exotoxin, but we have been unable to find any reports dealing with the production of enterotoxin (food-poisoning substance) on the media.…”

Gelatin as a Source of Growth-Promoting Substances for Bacteria

“…Since the original medium contained only a limited number of amino acids, another more elaborate synthetic medium was substituted for it. The latter contained small quantities of 15 amino acids, in addition to 0.2 per cent glucose and inorganic salts (Koser, Finkle, Dorfman, Gordon and Saunders, 1938). However, the resultant growth after the addition of Difco gelatin was as a rule no more rapid nor luxuriant than with the restricted synthetic medium.…”

“…Recent work on the growth requirements of microorganisms has thrown some light on the needs of several types, especially with respect to substances other than the ordinary amino acids. From the work of Schopfer (1935), Tatum, Wood and Peterson (1936), Williams and Rohrman (1936), Miller (1936), Knight (1937), Mueller (1937), Mueller and Cohen (1937), and Koser, Finkle, Dorfman, Gordon and Saunders (1938) it is evident that vitamin B1, beta alanine, and nicotinic acid, either singly or in certain combinations, are needed for the development of propionic acid bacteria, staphylococci, the diphtheria bacillus, several strains of yeast and a mold.…”

Growth of Non-Sporulating Anaerobic Bacteria of Intestinal Origin in Synthetic Media

“…The amino acid mixture, which was a modification of that used by Koser, Finkle, Dorfman, Gordon and Saunders (1938), consisted of 0.05 per cent each of dl-alanine, cysteine-HCl and d-glutamic acid, 0.02 per cent each of I-asparagine, glycine, 1-histidine-HCl, d-lysine-2 HCI and 1-tryptophane, 0.01 per cent each of d-arginine-HCI, dl-isoleucine, l-leucine, dl-methionine, I-proline, dl-beta-phenyl alanine, dl-threonine and dl-valine and 0.005 per cent 1-tyrosine.…”