Cell size of various lactic acid bacteria as determined by scanning electron microscope and image analysis

Cells from 48 pure lactic acid bacterial strains from the ACA-DC collection were studied under the scanning electron microscope (SEM) and the images were photographed and processed with an Image Analysis software. The diameters of several cocci and the lengths and widths of several lactobacilli strains were measured, then the size parameters were statistically analyzed by variance analysis. Significant differences were found between the cell sizes of the cocci strains (Streptococcus 1.07 to 1.21 um, Enterococcus 0.87 to 1.01 um, Lactococcus 0.75 to 0.95 um), but not between lengths and widths of the bacilli strains because too high variations were found in the last measurements. InraJElsevier, Paris. lactic acid bacteria / bacterial cell / SEM / image analysis / cell size Rsum -tude granuIomtrique des cellules de bactries lactiques par microscopie lectronique balayage associe l'analyse d'images. Des cellules de 48 souches pures de bactries lactiques de la collection ACA-DC ont t tudies par microscopie lectronique balayage (MEB).