The biosynthesis of cyclopropane fatty acids. III. pH Dependence of methyl hydrogen exchange: gas chromatographic – mass spectral studies

L-Methionine-methyl-d3 was administered to Lactobacillusplantarum and the deuterium content of the biosynthetic lactobacillic acid examined by gc–ms. By conducting the biosynthetic experiments in media of varying pH, it was shown that the production of d1-cyclopropane fatty acid increases with decreasing pH. Factors such as culture age and total activity of cyclopropane synthetase do not directly influence the extent of exchange.