TABLE 2.
Parameters used to calculate the cytoplasmic/external concentration ratio as a function of permeability when inward diffusion just balances dilution caused by exponential bacterial growth
| Parametera | Value | Source |
|---|---|---|
| μ | ln(2)/1,800 = 3.851 × 10−4 s−1 | Specific growth rate constant equivalent to a mean generation (doubling) time of 30 min |
| AGm+ve | 35.5 cm2 · (mg dry mass)−1 | Staphylococcus epidermidis surface; based on a spherical radius of 389 nm estimated from Fig. 5 of reference 66b |
| V3Gm+ve | 2.35 × 10−4 cm3 · (mg dry mass)−1 | S. epidermidis cytoplasm water volume, based on the cytoplasm spherical radius of 350 nm estimated from Fig. 5 of reference 66 and assuming 70% of the volume to be water (67)b |
| AGm−ve | 132 cm2 · (mg dry mass)−1 | Surface area of Salmonella enterica serovar Typhimurium (68) |
| V3Gm−ve | 1.4 × 10−3 cm3 · (mg dry mass)−1 | Cytoplasm water volume of E. coli (53, 69) |
a
Gm+ve and Gm−ve, measurements and estimates based on experimental data from, respectively, Gram-positive and Gram-negative bacteria.
b
The relationship between cell number and dry mass for a Gram-positive coccus was estimated to be 1.867 × 109 cells · (mg dry mass)−1 from data for Staphylococcus aureus (70).