Identification of Growth Stimulants for Streptococcus Lactis

Koburger, J. A. (North Carolina State College, Raleigh), M. L. Speck, and L. W. Aurand. Identification of growth stimulants for Streptococcus lactis. J. Bacteriol. 85:1051-1055. 1963-The growth of Streptococcus lactis in milk was accelerated by pancreas extract, and three distinct components that were detected by bioautography were isolated and identified. These were purified by precipitation with silver ions, and their silver salts were regenerated in acidic solution. After adsorption and elution from characoal, contaminating alpha-amino compounds were destroyed by treatment with ninhydrin. Final purification was by chromatography. Identification of the purified fractions was by paper chromatography, and by ultraviolet and infrared spectra. The active compounds were found to be inosine, hypoxanthine, and adenine.