Characterization of CDC group DF-3 by cellular fatty acid analysis

Fourteen strains of Centers for Disease Control group DF-3 bacteria were examined for cellular fatty acid composition to evaluate their chemical relatedness to known bacterial species and groups. The fatty acids were liberated from whole cells by base hydrolysis, methylated, and analyzed by capillary gas-liquid chromatography. All group DF-3 strains possessed a distinct fatty acid profile which was characterized by large amounts (24%) of 12-methyltetradecanoate (a-C15:0), moderate amounts of saturated iso-branched-chain acids (i-C14:0 and i-C15:0), and small to moderate amounts of both branched- and straight-chain hydroxy acids (3-OH C15:0, i-3-OH C16:0, 3-OH C16:0, and i-3-OH C17:0). This fatty acid profile was unique as compared with the profiles of other bacteria we have previously tested but was most similar to the profiles of Capnocytophaga species.