Type 2 IDI performs better than type 1 for improving lycopene production in metabolically engineered E. coli strains.
In this study a comparison was made between type 1 and type 2 isopentenyl diphosphate isomerases (IDI) in improving lycopene production in Escherichia coli. The corresponding genes of Bacillus licheniformis and the host (i(Bl) and i(Ec), respectively) were expressed in lycopene producing E. coli strains by pTlyci(Bl) and pTlyci(Ec) plasmids, under the control of tac promoter. The results showed that the overexpression of i(Ec) improved the lycopene production from 33 ± 1 in E. coli Tlyc to 68 ± 3 mg/gDCW in E. coli Tlyci(Ec). In contrast, the expression of i(Bl) increased the lycopene production more efficiently up to 80 ± 9 mg/gDCW in E. coli Tlyci(Bl). The introduction of a heterologous mevalonate pathway to elevate the IPP abundance resulted in a lycopene production up to 132 ± 5 mg/gDCW with i(Ec) in E. coli Tlyci(Ec)-mev and 181 ± 9 mg/gDCW with i(Bl) in E. coli Tlyci(Bl)-mev, that is, 4 and 5.6 times respectively. When fructose, mannose, arabinose, and acetate were each used as an auxiliary substrate with glycerol, lycopene production was inhibited by different extents. Among auxiliary substrates tested, only citrate was an improving one for lycopene production in all strains with a maximum of 198 ± 3 mg/gDCW in E. coli Tlyci(Bl)-mev. It may be concluded that the type 2 IDI performs better than the type 1 in metabolic engineering attempts for isoprenoid production in E. coli. In addition, the metabolic engineering of citrate pathway seems a promising approach to have more isoprenoid accumulation in E. coli.
Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P.O Box: 14965/161, Tehran, I. R. Iran.
Sara Abolhassani
SA
Rad
Hossein Shahbani
HS
Zahiri
Kambiz Akbari
KA
Noghabi
Sarah
S
Rajaei
Reza
R
Heidari
Leila
L
Mojallali
D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002244:Carbon / Q000378:metabolism; D019748:Carbon-Carbon Double Bond Isomerases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002338:Carotenoids / Q000096:biosynthesis*; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D045782:Hemiterpenes; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D000077276:Lycopene; D060847:Metabolic Engineering; D053858:Metabolic Networks and Pathways; D008798:Mevalonic Acid / Q000378:metabolism; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D045782:Hemiterpenes; D007527:Isoenzymes; D011994:Recombinant Proteins; D002338:Carotenoids; D002244:Carbon; D019748:Carbon-Carbon Double Bond Isomerases; C021453:isopentenyldiphosphate delta-isomerase; D008798:Mevalonic Acid; D000077276:Lycopene