Table 1. Force–Distance Regimes Used To Describe AFM Data in Figure 5b^a.

regimes	approximate fitting function	parameters	definition
(I) double layer	3	λD	Debye screening length (nm)
(II) osmotic brush	4	δL0 = exp(a1/b1)	the onset of linear compliance, capsule thickness: H ≈ 2δL0 (nm)
(III) Hertzian	5	E	Young’s modulus (Pa)
(IV) Hookean	6	kbac	elastic constant of bacteria cells (N/m)

^aA₀ describes the short-range van der Waals force (negligible when compared with the electrostatic force in this scenario), A₁ is the force magnitude for the long-range electrostatic interaction, d is the separation distance, d₀ is used to correct the relative separation distance, a₁ and b₁ are the reduced parameters of the full osmotic brush model for grafted polyelectrolyte brushes²⁹ (where ln(δ₀^L) = a₁/b₁), δ is the indented distance after probe contact, c is the correction term of the indented distance from a relative separation distance, R is the effective radius (R_probe, R_bac/(R_probe + R_bac)), where R_probe, R_bac are the radius of the probe and the indented bacteria, respectively, and v is the Poisson ratio of the bacterial cells, e.g., assumed equal to 0.5 as a first approximation for an isotropic elastic solid.⁶⁰ The main parameters that we investigated were the bacterial capsule thickness, the Debye screening length (λ_D), the effective Young’s modulus (E_eff), and the elastic constant of the K1 bacterial cells (k).