Fig 4.

Growth of G. oxydans Δupp (A), G. oxydans Δupp ΔcydAB (B), and G. oxydans Δupp ΔcyoBACD (C) in mannitol medium at 30°C under oxygen limitation. The 250-ml flasks contained 40 ml of medium and were shaken at 200 rpm with a shaking diameter of 50 mm. In the upper panels, the oxygen transfer rates (OTRs) and the carbon dioxide transfer rates (CTRs) of two independent cultures are shown. In the lower panels, the OD₆₀₀, the pH of the medium, and the concentrations of mannitol (Man), fructose (Fruc), and 5-keto-fructose (5-keto-Fruc) are shown. RAMOS experiments were conducted as duplicates and showed an excellent reproducibility. In panel A the maximal oxygen transfer capacity is illustrated as an example by a dashed horizontal line.