Fig. 6
Supplementation of copper, zinc and manganese sulfate to A. vinelandii ATCC9046 cultivations under microaerobic conditions. Cultivations were conducted in modified Burk’s medium with 3 g/L yeast extract Roth Batch 1. Standard deviations are given for n ≥ 3. Significant differences to the reference are marked with asterisks, corresponding to the significance level (* for 0.01 < p < 0.05, ** for 0.001 < p < 0.01 and *** for p < 0.001). A, B: For clarity, only every fifth measuring point of the OTR curves is shown. The number of replicates is given with n; if n = 2, the mean value is shown and the shadow depicts the difference of the two replicates. In A, the horizontal dashed line depicts the OTR value of 2 mmol/L/h for an easier comparison of the nominal cultivation time. C–E: All values are given as mean values and calculated from the following number of replicates: cell dry weight, n ≥ 8; alginate dry weight, n ≥ 6; broth viscosity, n ≥ 4; mean molecular weight, n ≥ 6. The flow curves and the acetylation degree data are provided as Additional file 1: Fig. S6. Cultivation conditions: 250 mL shake flasks, initial pH = 7.2, filling volume VL = 50 mL, temperature T = 29 °C, shaking frequency n = 165 rpm, shaking diameter d0 = 50 mm