Analysis of biomass yield

Biomass was quantified gravimetrically in triplicate by centrifuging 2 mL of culture (4000 rcf, 10 min), washing the pellets with 0.9% (w/v) NaCl and drying them at 105°C for 72h. Dry biomass concentration was then determined by weighing the dry pellets. Concentrations of residual glucose and L-arabinose in the cell-free supernatant were analyzed via HPLC (UltiMate 3000; Thermo Fisher, Waltham, MA) with a Supelcogel C-610H column (Supelco, Bellefonte, PA). The eluent was 0.1% H3PO4 and the flow rate constant at 0.5 mL/min.
YX/S was calculated for the time before induction and after induction, respectively (Equations 1 & 2). For this, only the net biomass accumulation, corrected for intracellular product, was taken into account.