Figure 5: Relative maintenance efforts, expressed as quotient ?, comparing the maintenance reduction considering ATP gain during PHB synthesis from MTBE with the reduction only due to the presence of PHB biomass. Calculations according to equations 19 to 22 were made assuming ? = 2, YmaxactBM = 0.789 g active biomass (g MTBE)-1, mS = 0.21 mmol MTBE g-1 h-1, KS = 1 mM and n = 1.