Figure 2. Rates of Respiration and Fermentation Evolve Continuously During Batch Growth at a Constant Growth Rate.

(A) Cell density (single cells per ml) during exponential growth on glucose as a sole source of carbon and energy.

(B) The levels of O₂ in the exhaust gas were measured continuously (every second) with a ZrO₂ electrochemical cell.

(C) The levels of CO₂ in the exhaust gas were measured continuously (every second) with infra red spectroscopy.

(D) Fluxes of O₂ uptake Ψ_O2 and CO₂ production Ψ_CO2 estimated from the data in (A) and (B) and eqn. 1–2; see Supplemental Information for details.

(E) Respiratory quotient (RQ), defined as the ratio of Ψ_CO2 to Ψ_O2.

(F) Rate of O₂ uptake per cell.

(G) Rate of CO₂ production per cell.

In all panels, error bars denote standard deviations. See also Figure S2.