Plot of optical density at 590 nm (open circles) and associated first derivative (ΔOD/Δt, closed circles) data associated with E. coli growth (C
~ 4,000 CFU mL-1) at 37°C in Luria-Bertani broth. Inset Figure: OD and first derivative data associated with growth (C
~ 7,000 CFU mL-1) at 37°C in a defined minimal medium (MM). The growth parameter, tm, calculated using Eq. 1, is shown as at the center of symmetry about the maximum in ΔOD/Δt.