Rapid identification of Erwinia chrysanthemi isolated from soft rotted eggplant and phalaenopsis sp. By lipid and fatty acid profiling

Rapid identification of Erwinia chrysanthemi isolated from an eggplant and a Phalaenopsis sp. was conducted by lipid and fatty acid profiling. In lipid profiles, the eggplant and phalaenopsis strains as well as E. chrysanthemi pv. chrysanthemi were differentiated from E. carotovora subsp. carotovora and E. carotovora subsp. atroseptica on the basis of the presence or absence of a spot at Rf 0.66, which was specific for E. carotovora. Further, marked differences were also observed in fatty acid composition of the strains. The ratios of the amount of lauric acid (12:0) and myristic acid (14:0) clearly differentiated eggplant and phalaenopsis strains and E. chrysanthemi pv. chrysanthemi from E. carotovora subsp. carotovora and E. carotovora subsp. atroseptica. Fatty acid profiles of the eggplant and phalaenopsis strains were identical with that of E. chrysanthemi pv. chrysanthemi. The results of lipid and fatty acid profiling indicated that the eggplant and phalaenopsis strains are E. chrysanthemi. Physiological and biochemical tests also confirmed the results. The lipid and fatty acid analysis will be a practical approach for differentiation and identification of E. chrysanthemi and E. carotovora at least presumptive level.