# Advances in the Metabolic Engineering of _Escherichia coli_ for the Manufacture of Monoterpenes
## 2 Engineering Endogenous MEP Pathway in Prokaryotic Chassis  
As a pivotal microbial chassis for bioengineering, prokaryotic _E. coli_ mainly use MEP pathway for isoprenoid biosynthesis, which usually unable to produce sufficient quantities of monoterepenes for industrial production. Although several groups indicated that the engineered MEP pathway could increase the level of isoprenoid production in _E. coli_, the common precursors IPP and DMAPP are  
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**Pathway** & **Strains of the E. coli** & **Origin of the Integrated Enzymes for the Monotepene Production** & **Engineering Design** & **Monoterpene Product** & **Monoterpene Yield, Culture and Recovery Methods** & **Reference** \\ \hline MG1665 & 1. AtoB and IDI from _E. coli_ & 2. KnockS and HHCMs & 1. Codon optimization & & & \\ MG1655 & 3. MK, PMK, and PMD from _Saccharomyces cerevisiae_ & 3. Fusion protein & & & 32.4 mg/L, twophase culture of dodecane organic layer & [34] \\  & 4. EGPS & 3. MK, PMK, and PMD from _Saccharomyces cerevisiae_ & 4. Integration of seven MEV pathway genes in one plasmid; integration of _Sprg_ and \(p\) in another plasmid & & & \\ BL21 (DE3) & 1. AtoB and IDI from _E. coli_ & 2. KnockS and HHCMs from _Saccharomyces cerevisiae_ & 3. Integration of seven MEV pathway genes in one plasmid; integration of _Sprg_ and \(l\) in another plasmid & & & \\ BL21 (DE3) & 3. MK, PMK, and PMD from _Saccharomyces cerevisiae_ & 3. PLK from _Methus putida_ & 3. Location of seven MEV pathway genes in one plasmid; integration of _Sprg_ and \(l\) in another plasmid & & & \\ MG1655 & 3. PLK from _Methus putida_ & 1. Codon optimization & & & & \\ BL21 (DE3) & 2. MK, PMK, PMK, and PMD from _Saccharomyces cerevisiae_ & 3. PLK from _Methus putida_ & 3. Integration of three upper pathways genes, _Sprg_ and \(l\) in one plasmid; integration of four lower MEV pathway genes in another plasmid & & & \\ MG1655 & 3. PLK from _Methus putida_ & 1. Codon optimization & & & & \\ MG1655 & 3. DT from _E. coli_ & 3. PLK from site-directed mutation of FPS & 3. Integration of _Sprg_ and \(l\) in one plasmid & & & \\  & 5. RGS from _Ciumiumium bisulfite_ & & & & & \\ \hline  & 1. AtoB and IDI from _E. coli_ & 1. Codon optimization & & & & \\  & 2. HMCS and HHCMs from _Saccharomyces cerevisiae_ & 2. KnockS and HHCMs from _Saccharomyces cerevisiae_ & 2. KnockS and HHCMs from _Saccharomyces cerevisiae_ & & & \\ DHI & 3. MK, PMK, and PMD from _Saccharomyces cerevisiae_ & 3. Integration of seven MEV pathway genes and \(l\) in & & & \\  & 4. EGPS from _Guzanus elegans_ & 4. EGPS from _Guzanus laevis_ & 3. Integration of _E. coli_ & & & 182.5 mg/L; twophase culture of decane organic layer & [37] \\  & 5. MIS from _Qurnea laevis_ & 1. Codon optimization & & & & \\ BL21 (DE3) & 1. MvzE and MwJ from _E. coli_ & 3. Identification of the role of acetylesteraser for converting germanide to _Saccharomyces cerevisiae_ & & & & \\ BL21 (DE3) & 2. Mvz, PMK, PMD and ID from _Saccharomyces cerevisiae_ & 4. Integration of three upper & & & & \\  & 3. EGPS from _Methus putida_ & & & & & \\  & 4. KGS from _Guzanus laevis_ & 1. Codon optimization & & & & \\  & 1. CroxE and MwJ from _E. coli_ & 2. Exogenous pathway & & & & \\ BL21 (DE3) & 2. Mvz, PMK, PMD and ID from _Saccharomyces cerevisiae_ & 3. Integration of seven MEV pathway genes and \(l\) in one plasmid; integration of _Sprg_ and \(l\) in another plasmid & & & \\  & 4. EGPS from _Guzanus laevis_ & 1. Codon optimization & & & & \\ BL21 (DE3) & 1. MvzE and MwJ from _E. coli_ & 3. Identification of the role of acetylesteraser for converting germanide to _Saccharomyces cerevisiae_ & & & & \\ BL21 (DE3) & 3. EGPS from _Methus putida_ & 4. EGPS from _Guzanus laevis_ & 4. Integration of seven MEV pathway genes and \(l\) in one plasmid; integration of _Sprg_ and \(l\) in another plasmid & & & \\  & 4. EGPS from _Guzanus laevis_ & 1. Codon optimization & & & & \\ BL21 (DE3) & 1. AtoB and IDI from _E. coli_ & 2.