CELL DIVISION IN A SPECIES OF ERWINIA: VIII. AMINO ACID COMPOSITION OF THE MUCOPEPTIDE IN DIVIDING AND NON-DIVIDING CELLS

Abstract

The Erwinia sp. studied possesses a discrete mucopeptide layer. This layer contains glutamic, diaminopimelic, and muramic acid, glucosamine, and alanine (1–1–1–1–2) as major components. Aspartic acid, glycine, and an unidentified ninhydrin-positive compound are also present but in lesser amounts. Content of glycine increases when cells are grown in a defined medium in the presence of glycine. Serine is present in the mucopeptide when cells are grown in the presence of D-serine, an inhibitor of cell division. Serine can partially replace glycine. Incorporation of serine is not significantly decreased by agents capable of preventing division inhibition by D-serine (pantoyl lactone or ammonium chloride). A new method for isolation of pure mucopeptide is presented.