Characterization of growth stimulants in corn steep for lactic streptococci

The production of acid in milk cultures of lactic streptococci was stimulated by the addition of corn steep liquor. Separation by ion-exchange and paper chromatography indicated the presence of four major stimulatory components in the corn steep. Some variation was noted in the response of the lactic streptococci to the individual stimulatory components. The four components were further purified by paper and column chromatography. One of the four stimulatory components stained positively on chromatograms with ninhydrin. The remaining stimulatory components were detectable only by bioautography. All four components were unstable to acid hydrolysis and absorbed ultraviolet light between 230 and 275 nm in aqueous solution. The stimulatory components did not contain pentoses, suggesting that they were not nucleotides or nucleosides; however, they might be purine or pyrimidine bases.