Identification of Stimulants for Lactobacillus bulgaricus in Tomato Juice

Acid production in milk by Lactobacillus bulgaricus was stimulated by tomato juice or its serum. Preliminary purification of the stimulants involved adsorption and elution on a cation-exchange resin. Unidimensional paper chromatography in two solvent systems was employed in further isolation and purification. Identification of the stimulatory components was based on ultraviolet spectral analysis and thin-layer chromatography. The stimulants were identified as adenine and adenosine.