Fig. 4.

Simulated respiration rates (mmol O₂ g⁻¹ h⁻¹) at several growth rates (μ, h⁻¹). Regression through these points yields a straight line with an intercept at μ = 0 of 0.53 mmol O₂ g⁻¹ h⁻¹. This value is the oxygen uptake rate through respiration which is necessary for maintenance purposes. The maintenance fraction of the respiration rate is also plotted and shows which part of respiration is used for maintenance purposes. This graph also shows the simulated biomass yields on light energy (Y _xE, g mol⁻¹) for these growth rates. The simulations give an ideal situation since light saturation is not modeled. If light saturation would be taken into account the yield would reach an optimum and decrease as soon as light saturation occurs