The Nitrogen Requirements of Some Members of the Viridans Group of Streptococci

Abstract

The amino acid. requirements of certain members of the viridans group of streptococci have been investigated. These requirements have not been found to be uniform among strains of StreptoooccUB bovis. Rumen strains of Strep. bows require, in addition to 20 amino acids, rumen liquor or an extract of rumen liquor or certain other organic complexes. The chemical nature of the active factor suggests a peptide . . The essential amino acids for the faecal strains of Strep. boviB were glutamic acid, aspartic acid, leucine, valine, asparagine, and histidine.