Figure 1

mreB mutant cells have rougher and softer cell walls. Cell wall structure and mechanical properties of wild-type and ΔmreB cells exponentially growing in LB medium in the presence and in the absence of 25 mM MgSO₄. (a–c) phase contrast images. Scale bars, 2 µm. (d–i) AFM elasticity map (d–f) and topography (g–i). AFM scan size: wild-type, 0.75*1.71 µm²; ΔmreB, 0.81*1.67 µm²; ΔmreB + Mg²⁺, 0.69*1.51 µm². (j-l) Representative TEM transversal sections. Scale bars, 0.2 µm. (m, n) Average elasticity (m) and roughness (n) of the cell envelope determined from the AFM analyses. Bars indicate standard deviation.