Gas-Liquid Chromatographic Determination of Propionic Acid Production Differentiates between the Food-Poisoning...

Fatty acids of 32 strains belonging to five types of Clostridium perfringens were extracted from the supernatant liquid of cultures in various different media prepared with or without the addition of sugar and examined by application of the gas-liquid chromatographic technique. The major products in nearly all media were acetic, propionic and butyric acid among the volatile fatty acids and only lactic acid among the nonvolatile fatty acids. Quantitative comparison of the resulting chromatograms with regard to the presence and relative amounts of propionic acid as one of the large major peaks revealed clear differences between the toxigenic types and the food-poisoning strains of this organism. In cooked meat medium containing 2% fructose, all the toxigenic-type strains produced propionic acid, but the food-poisoning strains tested entirely lacked production of this acid. This differentiation characteristic may be useful in routine laboratory bacteriology.