Metabolic engineering of Escherichia coli for efficient ectoine production

Ectoine is a high-value stabilizer and protective agent with various applications in enzyme industry, cosmetics, biomedicine. In this study, rational engineering strategies have been implemented Escherichia coli to efficiently produce ectoine. First, the synthetic pathway of ectoine was constructed E. MG1655 by introducing an artificial thermal switch system harboring ectABC cluster from Halomonas elongate, resulting strain produced 1.95 g/L Second, crr encoding glucose-specific II domain A phosphotransferase iclR glyoxylate shunt transcriptional repressor were deleted for enhancing oxaloacetate supply, leading increasement titer 9.09 g/L. Third, thrA bifunctional aspartokinase/homoserine dehydrogenase removed genome weaken competitive pathway; simultaneously, endogenous feedback-resistant lysC overexpressed complement enzymatic activity deficiency aspartate kinase, 30.36% increase titer. Next, expression phosphoenolpyruvate carboxylase modulated varying gradient strength promoters accelerate biosynthesis efficiency Finally, aspDH Pseudomonas aeruginosa PAO1 further improve The final MWZ003/pFT28-ectABC-EclysC*-aspDH-ppc3 30.37 after 36-h fed-batch fermentation yield 0.132 g/g glucose productivity 0.844 g/(L h).