Fatty acid profiles of the outer membrane of ATCC strains 35405, 35404 and 33521 of Treponema denticola.

The fatty acid composition of the outer membrane (outer sheath) of Treponema denticola is not known. This study examined the fatty acid profiles of the outer membranes of T. denticola ATCC strains 35405, 35404, 33521. Homogeneous outer membranes were prepared from the three strains of T. denticola. The fatty acids were extracted and converted to methyl esters, and their mass spectra were determined with a sensitive Hewlett-Packard 5880A-5970 gas chromatography-mass spectrometry system. Fatty acids were identified by comparing the unknown fatty acid mass spectra to computer stored known mass spectra standards. Dodecanoic, 2 hydroxy dodecanoic, tridecanoic, tetradecanoic, pentadecanoic, hexadecanoic, 2-hydroxy hexadecanoic and octadecanoic acid were found in the assay spirochetes yielding correlation indices (r) of 0.8-1.00. Isotetradecanoic acid was found in the outer membranes of strains 33521 and 35405 (r = 0.913-0.967). Anteiso pentadecanoic and heptadecanoic acids were found in the outer membrane of strains 33521 and 35404 (r = 0.941-0.996), while cis 9, 12 octadecadienoic was found only in the outer sheath of strain 35405 (r = 0.922-0.958). The average concentration of dodecanoic, tridecanoic, tetradecanoic, pentadecanoic, hexadecanoic, heptadecanoic and octadecanoic acid in the outer membranes of strains 35405, 35404 and 33521 were as follows. Strain 35404: 138, 178, 845, 296, 751, not detected, and 699 nanogram per mg dry weight of the outer membrane. Strain 35404: 96, 125, 670, 306, 597, 38 and 249 nanograms per mg dry weight of the outer membrane. Strain 33521: 323, 135, 1650, 125, 9080, 235 and 618 nanograms per mg dry weight of the outer membrane.(ABSTRACT TRUNCATED AT 250 WORDS)