Changes in morphology and cell wall structure that occur during growth of Vibrio sp. NCTC4716 in batch culture.

When grown in batch culture in various media Vibrio sp. NCTC4716 displayed a distinct sequence of morphological forms. Organisms occurred as stout, almost straight rods in exponential phase, curved rods (characteristic of Vibrio spp.) in stationary phase, and predominantly as spheres in decline phase. The spheres were formed after growth had ceased due to the depletion of the carbon/energy source. They were not viable, survival of the culture depending on the few rod forms that remained during the decline phase. The spheres seemingly arose from degradation, but not complete removal, of the peptidoglycan present in the walls. Though spheres contained less nucleic acid and low molecular weight cytoplasmic constituents than did rods, many still possessed an intact cytoplasmic membrane.