Table 1 The steps in the metabolic engineering of E. coli for isoprene production in this work
Step | Optimization strategy | Strain | Plasmids | Isoprene production (mg/L) | Improvement over original strain (fold) |
|---|---|---|---|---|---|
0 | – | LMJ0 | pYJM14/ pYJM20 | 287 | – |
1 | Enzyme screening and RBS sequence optimization of key enzyme, IDI | LMJ8 | pT-EEE-IDIsa-RBS/ pYJM20 | 451 | 1.57 |
2 | Enzyme screening and RBS sequence optimization of key enzyme, MK | LMJ17 | pT-EEI-MKmm-RBS/ pYJM20 | 402 | 1.4 |
3 | Enzyme screening of key enzyme, IspS | LMJ11 | pYJM14/ pA-MM-ispSib | 504 | 1.9 |
4 | Combinatorial optimization of key enzymes, IDI, MK and IspS | LMJ12 | pT-EE-IDIsa-RBS/ pA-MM-ispSib | 599 | 2.1 |
5 | RBS sequence optimization of non-key enzyme, MvaE and ERG19 | LMJ22 | pT-EEI-ERG19-RBS2/ pA-MM-ispSib | 698 | 2.6 |