Table 4.
Physiological characterization of wild-type and mutant E. coli strains as microbial cell factories for PHB biosynthesis in shaken-flask cultures.
| E. coli strain | Relevant characteristics | Physiological parametera |
||
|---|---|---|---|---|
| μ (h−1) | CDW (g l−1) | Y A/S (mol mol−1) | ||
| BW25113 | Wild-type strain | 0.74 ± 0.04 | 3.8 ± 0.2 | 0.64 ± 0.05 |
| JW2293-1 | Δpta | 0.44 ± 0.03 | 2.9 ± 0.3 | 0.13 ± 0.02 |
| JW2293P | Δpta phaC1AB1+ | 0.51 ± 0.07 | 3.5 ± 0.1 | 0.05 ± 0.02 |
| TA2293P | Δpta ykgH:mini-Tn5(phaC1AB1) | 0.63 ± 0.05 | 4.2 ± 0.4 | 0.09 ± 0.03 |
aCells were grown aerobically in M9 minimal medium containing 30 g l−1 glucose as the sole carbon source. The specific growth rate (microns) was determined during logarithmic growth, whereas the final cell density (expressed as the cell dry weight, CDW) and the molar yield of acetate on glucose (YA/S) were calculated after 24 h of incubation. Reported results represent the mean value ± SD of triplicate measurements from at least two independent cultures.