Table 4 Averaged production values of C4–C7 carboxylates in the three steady states (in phases B, C and F) of the bioreactor cultivation
Steady-state parameter | Phase | ELR (g L−1 d−1) | HRT (h) | Carboxylic acids | |||
|---|---|---|---|---|---|---|---|
Butyrate | Valerate | Caproate | Heptanoate | ||||
Concentration (mM) | B | 1.7 | 36 | 2.1 ± 0.2 | 5.9 ± 0.2 | 5.8 ± 0.3 | 1.7 ± 0.2 |
|  | C | 3.1 | 36 | 1.9 ± 0.1 | 8.5 ± 0.2 | 14.8 ± 0.5 | 4.1 ± 0.2 |
|  | F | 6.7 | 54 | 2.1 ± 0.2 | 12.5 ± 0.8 | 27.6 ± 1.3 | 6.5 ± 0.3 |
Observed prod. rate (mmol L−1 d−1) | B | 1.7 | 36 | 1.4 ± 0.1 | 4.0 ± 0.1 | 3.9 ± 0.2 | 1.2 ± 0.1 |
C | 3.1 | 36 | 1.3 ± 0.1 | 5.7 ± 0.1 | 9.9 ± 0.3 | 2.8 ± 0.1 | |
|  | F | 6.7 | 54 | 0.9 ± 0.1 | 5.5 ± 0.4 | 12.2 ± 0.6 | 2.9 ± 0.1 |
% Specificity (moli/moltotal products) | B | 1.7 | 36 | 9.2 ± 1.1 | 26.3 ± 0.9 | 25.8 ± 1.9 | 7.6 ± 0.8 |
C | 3.1 | 36 | 5.6 ± 0.3 | 24.8 ± 0.2 | 43.3 ± 1.4 | 12.2 ± 0.7 | |
F | 6.7 | 54 | 3.4 ± 0.4 | 20.9 ± 0.6 | 46.3 ± 0.5 | 10.9 ± 0.2 | |
% Selectivity (e-moli/e-moleth. consumed) | B | 1.7 | 36 | 6.7 ± 0.5 | 25.2 ± 0.7 | 30.4 ± 1.8 | 10.7 ± 1.2 |
C | 3.1 | 36 | 3.5 ± 0.2 | 19.9 ± 0.4 | 42.7 ± 1.2 | 14.2 ± 0.8 | |
F | 6.7 | 54 | 2.0 ± 0.2 | 15.7 ± 0.7 | 42.8 ± 1.5 | 11.9 ± 0.4 | |