Volatile Fatty Acid Requirement of a Strain of Listeria Monocytogenes.

Larson, A. D. (Louisiana State University, Baton Rouge), L. V. Hattier, and C. S. McCleskey. Volatile fatty acid requirement of a strain of Listeria monocytogenes. J. Bacteriol. 89:819-824. 1965.-Listeria monocytogenes strain 2 requires either isobutyric or 2-methylbutyric acid for growth. Elucidation of this requirement began with characterization of the growth-enhancing substance in culture filtrates of Aerobacter aerogenes. A. aerogenes required tryptose, glucose, and aerobic conditions for excretion of active fatty acids into the medium. Commercial preparations of isobutyric, 2-methylbutyric, isovaleric, 3-methylvaleric, and n-valeric acid supported the growth of strain 2. Purification of these fatty acids by gas chromatography demonstrated that strain 2 responded significantly only to isobutyric and 2-methylbutyric acid. Amines, alcohols, and hydroxy fatty acids, which were structurally related to the active acids, did not satisfy the fatty acid requirement of L. monocytogenes strain 2. Only one isolate (strain 2) of 128 cultures of L. monocytogenes required volatile fatty acid for growth.