Rapid construction of E.coli chassis with genome multi-position
integration of isopentenol utilization pathway for efficient and stable
terpenoid accumulation
Abstract
The isopentenol utilization pathway (IUP) is potential in terpenoids
synthesis. This study aimed to construct IUP-employed E. coli chassis
for stably synthesizing terpenoids. As to effectiveness, promotor
engineering strategy was employed to regulate IUP expression level,
while ribosome-binding site (RBS) library of the key enzyme was
constructed for screening the optimal RBS, followed by optimization of
concentration of inducer and substrates, the titer of reporting
production, lycopene, from 0.087 to 8.67 mg/OD600. As about stability,
the IUP expression cassette was integrated into the genome through
transposition tool based on CRISPR-associated transposases. Results
showed that the strain with 13 copies produced 1.78-fold lycopene titer
that of the controlled strain with IUP-harbored plasmid, and it
exhibited stable expression after ten successions while the plasmid loss
was observed in the controlled strain in the 3rd succession. This
strategy provides valuable information for rapid construction of highly
effective and stable chassis employing IUP for terpenoids production.