Box 2.
Flux-based micro-aerated control (FMC): equations for updating fresh medium feeding and air flow rates. The values for constants and other conditions are: \({\text{y}}_{{{\text{CO}}_{ 2} , {\text{ N}}_{ 2} }}\) = 0.01*10−2; Tin = 294.25 K; Pout = 1 atm; R = 0.08206*10−3 L atm mmol−1 K−1. Qgas,out, \({\text{y}}_{{{\text{CO}}_{ 2} , {\text{ in}}}}\), and \({\text{y}}_{{{\text{O}}_{ 2} , {\text{ in}}}}\) were estimated through mass balance. The variables \({\text{y}}_{{{\text{CO}}_{ 2} , {\text{ out}}}}\), \({\text{y}}_{{{\text{O}}_{ 2} , {\text{ out}}}}\) and Tout were measured on-line and accessed through the supervisory software. \({\text{J}}_{\text{s}}^{\text{MC}}\), \({\text{J}}_{{{\text{O}}_2}}^{\text{MC}}\), \({\text{J}}_{{{\text{O}}_{2} }}^{\text{CA}}\), \({\text{J}}_{{{\text{CO}}_{2} }}^{\text{CA}}\) are expressed in mmol g −1DW h−1. QN2, QAIR and F were manipulated and are expressed in L h−1. *Mathematical correlations in Results Metabolic Models Simulations and Correlations (Eqs. 1 and 2, respectively)