Fig. 3

Effect of different O₂ concentrations on gas transfer rates of P. vulgatus shake flask cultivations. Online data of (a) carbon dioxide transfer rate (CTR) and (b) total gas transfer rate (TGTR) and (c) oxygen transfer rate (OTR). Shadows indicate standard deviations of four biological replicates. Different successively conducted experimental runs are indicated by different symbols in the legend (*,+,-,~). Dashed horizontal line in (c) indicates an OTR of 0 mmol L^− 1 h^− 1. Experimental setup is illustrated in Fig. 5b. Hydrogen transfer rate (HTR) plotted over CTR corresponding to this experiment can be found in Fig. S2. Medium: DMM-G, c_Glucose = 6 g L^− 1, c_buffer = 50 mM MOPS, T = 37 °C, n = 100 rpm, V_L = 50 mL, initial OD_600nm = 0.29, initial pH after inoculation = 6.9–7.1, vvm = 0.2 min^− 1, different gas mixtures of O₂ & 4% CO₂ in N₂, as indicated in the legend