Table 2.
Fermentation characteristics of the wild type E. coli and its phoB mutant in the aerobic chemostat culture under two phosphate concentrations (100% and 55%) and two pH values (7.0 and 6.0) at the dilution rate of 0.2 h-1.
| Fermentation parameters | P-rich condition (100%) | Lower P concentration (55%) | ||
|---|---|---|---|---|
| pH 7.0 | pH 6.0 | pH 6.0 | ||
| Biomass concentration (g/l) | Wild | 3.86 ± 0.03 | 3.680 ± 0.002 | 1.960 ± 0.001 |
| ΔphoB | 3.44 ± 0.04 | _ | 3.040 ± 0.001 | |
| Glucose concentration (g/l) | Wild | 0.660 ± 0.004 | 1.053 ± 0.010 | 0.677 ± 0.050 |
| ΔphoB | 1.59 ± 0.29 | _ | 1.145 ± 0.020 | |
| Acetate concentration (g/l) | Wild | 0.046 ± 0.002 | 0.468 ± 0.003 | 0.519 ± 0.001 |
| ΔphoB | 0.255 ± 0.130 | _ | 0.510 ± 0.007 | |
| Specific glucose uptake rate (mmol/gDCW/h) | Wild | 2.69 ± 0.05 | 2.700 ± 0.001 | 5.285 ± 0.031 |
| ΔphoB | 2.72 ± 0.09 | _ | 3.24 ± 0.01 | |
| Specific acetate production rate (mmol/gDCW/h) | Wild | 0.040 ± 0.002 | 0.424 ± 0.003 | 0.882 ± 0.001 |
| ΔphoB | 0.247 ± 0.080 | _ | 0.559 ± 0.007 | |
Note: " - " indicates that no data was collected for this condition. The standard deviation was obtained by triplicate measurements.