Amino Acids and Utilization of Sodium Caseinate by Lactic Streptococci

The ability of strains of lactic streptococci to utilize unhydrolyzed sodium caseinate as the nitrogen source in an otherwise complete, chemically denned medium did not appear to be related to their minimal amino acid requirements. Sodium caseinate had a sparing effect on the requirement for some amino acids of some strains of streptococci that did not use caseinate, but the amino acids spared varied with the strain. However, leucine, isoleucine, methionine, and valine appeared to be essential for this group of organisms in the presence or absence of sodium caseinate.