Figure 4

Comparison of the oxygen transfer rate (OTR), pH and glucose concentration during the cultivation of E. coli BL21 pRSET eYFP-IL6 with different buffer concentrations and controlled-release discs. a: with 0.2 M MOPS buffer, b: with 0.1 M MOPS buffer, c: with 0.1 M MOPS buffer and additional 3 controlled release discs. OTR (■); pH (▲); glucose concentration (○); OD₆₀₀ (◇); acetate concentration (★); experimental conditions: Wilms-MOPS medium with 20 g/L glucose, 37°C; 10 mL filling volume; shaking diameter (d₀) 50 mm; 350 rpm; OD_600,α = 0.5; pH₀ = 7.5; controlled-release discs: D = 15 mm; H = 1.1 mm; 30% (w/w) Na₂CO₃.