| Comments |
p.1439 left column bottom paragraph:"It is well known that E. coli changes its size in response to nutrient availability (Schaechter et al., 1958). If cell size homeostasis works through a constant elongation irrespective of the composition of the growth medium, [investigators] would expect the fixed cell length extension in nutrient-poor medium to be smaller than in the nutrient-rich LB medium, with the average ?L value matching the average Lb value for each growth medium. To test this hypothesis, [they] grew E. coli BW25113 in microfluidic chambers with M9-supplemented medium (M9 salts supplemented with 0.1% casamino acids and 0.2% glucose) instead of LB medium. Under steady-growth conditions (Figure S4), the cell-cycle time in M9 supplemented medium was longer than in LB medium with T = 42 ± 12 min, and the cell lengths at birth and at division were shifted to lower values (Figure 5A), with Lb = 2.32 ± 0.38 µm and Ld = 4.59 ± 0.71 µm. Cell size control in M9 medium remains precise, with CV values of 17% and 15% for Lb and Ld, respectively." p.1444 right column 3rd paragraph:"M9-supplemented medium=(6 g/l Na2HPO4·7H2O, 3 g/l KH2PO4, 0.5 g/l NaCl, 1 g NH4Cl, 2 mM MgSO4, 1 mg/l thiamine supplemented with 0.1% casamino acids and 0.2% glucose)." |