Figure 3: Cryo-electron tomography images from 3D reconstructions of ultra-small bacteria.
From: Diverse uncultivated ultra-small bacterial cells in groundwater
(a–e) One-voxel-thick slices. (a) 3D reconstruction reveals a very dense cytoplasmic compartment and a conspicuous, complex cell wall enveloped by a periodic surface layer (S-layer). The high contrast sub-cellular bodies located at cell ends are putative ribosomes. Scale bar, 100 nm. The full reconstruction is provided in Supplementary Movie 1. (b) Within the cytoplasm, periodic fringes (normal to yellow line) display a 5.6-nm spacing (see insert), consistent with tightly packed DNA. Scale bar, 50 nm. (c,d) Pili-like structures associated with cell surfaces. Scale bars, 20 nm. The full reconstruction for d is provided in Supplementary Movie 2. (e) Top view of the repeating unit of the S-layer. Scale bar, 20 nm.
