FIGURE 2.

The effects of changing the B. atrophaeus spore environment from hydrated to dehydrated states. (a) Phase image and height image (inset) detail of a B. atrophaeus spore in water, showing several shallow wrinkles. (b) The same spore after drying, showing many adsorbed stray rodlets, and a 60-nm high ridge (indicated with R). Loose stray rodlets sediment from the bulk solution upon drying of the sample. Stray rodlets are present on the surfaces of all air-dried spores. (c) Width change of 35 individual B. atrophaeus spores. Depicted is the individual measured spore width for a set of dehydrated (24 h) (diamonds, dashed trend line) and rehydrated (2 h) spores (triangles, dotted trend line), as a function of the size of the originally hydrated spore. For ease of comparison, the original hydrated spore width is (redundantly) depicted as circles, which by definition lie on the solid y = x line. Thus, the three data points for one individual spore, depicted with the same color, are all on the same vertical line. Several spores detached from the substrate during rehydration, which resulted in fewer experimental points for rehydrated spores (triangles). On average, spore size is reduced to 88% for dried spores, and returns to 97% of the original width for rehydrated spores (see text). Scale bar in a and b, 200 nm.