Fig. 3.

Nutrient uptake through single porins in absence of other porins. (A) Nutrient consumption rates of PA14 Δ40 strains expressing a single porin from a low-copy-number plasmid. Means and averages for three independent cultures (single-porin strains) or 21 cultures (PA14, PA14 Δ40) are shown. (B) Substrate selectivity of 15 porins determined in single-porin strains. The capacity of each porin to boost nutrient consumption from baseline levels in PA14 Δ40 to wild-type levels is shown. Porins and nutrients are grouped based on unsupervised clustering. (C) Permeability of 472 antimicrobial compounds with detectable antipseudomonal activity (15). Following the published analysis, compounds are grouped in permeability classes according to the MIC values for efflux-deficient P. aeruginosa strains with intact (P Δ6) or abolished (P Δ6-pore) outer membrane permeability barrier (class 0, MIC of PA Δ6-pore is less than 20% of PA Δ6; 1, 20 to 40%; 2, 40 to 60%, 3, 60 to 80%; 4 more than 80%). Statistical significance was analyzed with the χ² test.