Fig. 6
Cultivation of Paenibacillus polymyxa in reduced Moppa medium in microtiter plate and fermenter. Reduced Moppa medium (specified in Table 2). Initial concentrations were: 55.7–58.2 g/L maltose, 2.7–3.3 g/L glucose, 3.1–3.8 g/L citrate. a Oxygen transfer rate (OTR) in microtiter plate or fermenter, b Final optical density (OD) and pH, c Final maltose, glucose and citrate concentration. c d.l. means that concentrations of components were lower than the detection limit. Final lactate concentrations were lower than the detection limit. Parameters in b and c were determined after 133.3 h in microtiter plate (corresponds to 121.0 h cultivation time after shift) and after 119 h in fermenter. Initial osmolality in reduced Moppa medium in microtiter plate is 0.95 osmol/kg and in fermenter is 0.48 osmol/kg. Cultivation conditions: microtiter plate: temperature 33 °C, 48-round well plate, filling volume 0.8 mL, shaking frequency 1000 rpm, shaking diameter 3 mm, 0.2 M MES, initial pH 7.0. For clarity, only every 18th measuring point over time is marked as a symbol. Mean values for OTR of four replicates with standard deviations as shadows are shown for microtiter plate. Standard deviations are not well recognizable, because they are small. b-c For offline analysis, samples (wells) of the replicates of the OTR measurement were pooled at the end of the microtiter plate experiment. OD measurement of pooled sample was performed in triplicate and the mean value with standard deviation depicted as error bar is shown. pH and concentrations of sugars were determined in a single measurement of pooled sample. Fermenter: temperature 33 °C, filling volume 1 L, pH control at pH 6.5 with NH3 • aq and H3PO4 solutions, without MES buffer. For clarity, only every 720th measuring point is marked as a symbol. The cultivation in reduced Moppa medium in microtiter plate is also shown in Additional file 1: Figure S16