Figure 4: Cryo-TEM images (2D) documenting morphology, size and some morphological features of ultra-small bacteria.
From: Diverse uncultivated ultra-small bacterial cells in groundwater
The cell envelope includes a remarkable and distinct S-layer. Pili-like structures are clearly discernible: numerous radiating pili-like structures cover the surface of the cell in a, whereas polar pili-like structures occur on the cell in b, apparently connecting it to an adjacent bacterium (only part of the bacterium shown). (c) A dividing ultra-small bacterium in contact with a Spirocheate cell (only small region shown; also see Supplementary Fig. 14). Note the contrast at the interface, suggesting cell-to-cell interaction. Three bacteriophages are associated with the surface of the cell in d. Scale bars, 100 nm.
