The nutrient demand of S-dublin strains was investigated. Media on chemically defined basis for culturing of S. dublin are recommended with reference to the above studies. The definition includes Na2HPO4, KH2PO4, NaCl, glucose, the amino acids L-asparaginic acid, L-cystine, L-glutamic acid, serine, and L-threonine, and nicotinamide as vitamin component. Such media will be quite favourable for certain culturing problems, but complex substrate (yeast extract, peptone, tryptone) should be added for high yields.