Comparative biosynthesis of ornithine and lysine by Mycoplasma and L forms.

Smith, Paul F. (University of South Dakota, Vermillion). Comparative biosynthesis of ornithine and lysine by Mycoplasma and L forms. J. Bacteriol. 92:164-169. 1966.-Seven species of Mycoplasma, two L forms not requiring salt and their parent bacteria, and two yeasts were examined for enzymes involved in the biosynthesis of ornithine and lysine. All organisms tested, except two species of Mycoplasma and the yeasts, decarboxylated meso-alpha, epsilon-diaminopimelic acid. None of the Mycoplasma species or L forms was capable either of reducing alpha-aminoadipic acid to its semialdehyde or of incorporating alpha-aminoadipic acid-6-C(14) into lysine. All organisms, except the yeasts and Mycoplasma sp. caprine strain 14, acetylated glutamic acid, and all organisms possessed N(alpha)-acetyl-l-ornithine:2-oxo-glutarate aminotransferase activity. N(alpha)-acetylornithase activity was negligible in all organisms except Proteus and its L form. No transacetylation between acetylglutamic acid and ornithine, and vice versa, was demonstrable in any of the organisms. Mycoplasma species appear to possess the bacterial pathway to lysine. Ornithine does not appear to arise from glutamic acid.