Fig. 6
From: High cell density cultivation by anaerobic respiration
Glucose mixed with trace elements results in growth inhibition. P. denitrificans was inoculated in serum vials (50 mL medium M1; initial 1 vol% O2 in the headspace, 5 mM KNO3, and 10 mM glucose). After depletion of O2 and onset of denitrification, all vials got an additional 5 mM KNO3 and either glucose solution alone (3.125 M, 0.16 mL vial−1) or as a mix with trace elements. The figure shows O2-depletion (µmol vial−1, line) and subsequent N2 production (µmol N vial−1, circle) in the cultures (n = 2 replicate vials per treatment, standard deviations shown as vertical bars). The insert shows the estimated electron flow to NOx, Ve (µmol e− vial−1 h−1) in the period after the injection. The result demonstrates that respiration was severely inhibited by the mixture of glucose and trace elements