RESOLVING THE HIGH-RESOLUTION ARCHITECTURE, ASSEMBLY AND FUNCTIONAL REPERTOIRE OF BACTERIAL SYSTEMS BY IN VITRO ATOMIC FORCE MICROSCOPY - Life at the Nanoscale: Atomic Force Microscopy of Live Cells - page 80

spores grown in G medium, patches of rodlet structure were visualized on
the spore coat ( Fig. 4.6c,d ) . These data establish that outer coat structural
motifs are directly correlated to differences in the medium conditions during
sporulation.

(a) (b) (c) (d)

Figure 4.6. AFM images showing the outer coat structure of B. thuringiensis spores
grown in NB medium (a,b) and G medium (c,d). Honeycomb and rodlet crystalline
structures are indicated with hexagons (a,b) and circles (d), respectively.

These indings validate that AFM can identify formulation-speciic
structural attributes that could be used in bioforensics to reconstruct spore
formulation conditions. We have recently successfully demonstrated this
approach for probing the formulation-dependent spore coat structures of

B.

anthracis spores.

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4.1.4 AFM-Based Immunolabelling of the Proteomic Structures

AFM provides high-resolution topographical information about the spatial
and temporal distribution of macromolecules in biological samples. However,
simultaneous near-molecular resolution topographical imaging of biological
structures and speciic recognition of the proteins forming these structures
is currently lacking. Of particular importance is the identiication of the
protein composition of pathogen and microbial surfaces. Pathogen outer
surface structures (e.g. virus membranes and capsids, as well as bacterial
cell walls, spore coats and exosporia) typically contain multiple proteins.
While it is known to a certain degree which proteins are expressed for these
surface structures, it is often unknown which of these are exposed on the
outside of these structures and which are embedded within the structures.