Amino acid precursors of Myxococcus xanthus antibiotic TA.

The production of Myxococcus xanthus antibiotic TA was stimulated by addition of alanine, serine and glycine to Casitone medium. These three amino acids served as the major biosynthetic precursors of the antibiotic. Alanine and serine were incorporated via acetate. In Casitone medium supplemented with alanine and serine, 29 to 30 of the 34 carbon atoms of antibiotic TA were derived from these two amino acids. Both carbon atoms of glycine were incorporated into antibiotic TA by a mechanism not involving acetate as an intermediate. Antibiotic TA was split into two fragments by alkaline hydrolysis followed by periodate oxidation. Radioactive alanine was incorporated into both fragments, whereas glycine was incorporated only into the smaller, polar fragment.