Differentiation of Erwinia carotovora ssp. carotovora and E. carotovora ssp. atroseptica on the basis of cellular fatty acid composition

Abstract

The cellular fatty acids of Erwinia carotovora were analyzed by gas–liquid chromatography with a fused-silica capillary column. All strains contained, in decreasing order of amount present, 9-hexadecenoic acid (16:1), hexadecanoic acid (16:0), 9-octadecenoic acid (18:1), dodecanoic acid (12:0), 3-hydroxytetradecanoic acid (3-OH-14:0), and tetradecanoic acid (14:0). In addition some strains contained a small amount of 13, 15, 17, and 18 carbon saturated fatty acids. Strains of E. carotovora ssp. atroseptica (Eca) and E. carotovora ssp. carotovora (Ecc) from potato could be differentiated on the basis of three different fatty acid ratios. The Ecc strains had ratios of >3.71 for 12:0/14:0, <4.87 for 16:0/12:0, and <2.70 for 16:1/18:1, while the Eca strains had contrasting values for each of the ratios. Non-potato strains of E. carotovora including strains that were neither Ecc nor Eca on the basis of biochemical reactions were more variable in fatty acid composition than the potato strains, but the fatty acid ratios were generally of the Ecc type.