Metabolism of [¹⁴C]bicarbonate byStreptococcus lactis: identification and distribution of labelled compounds

Summary Streptococcus lactis C10, grown in tryptone–yeast extract–lactose broth containing [ 14 C] bicarbonate, incorporated radioactivity into the protein and nucleic acid fractions of the cell as well as into compounds which were excreted by the organism into the growth medium. Aspartic acid was the first compound to be labelled and was the only amino acid labelled in the cell protein. All 4 bases were labelled in the cell RNA. Aspartic, succinic and lactic acids were the radioactive compounds excreted into the growth medium.