title: Engineering Escherichia coli for selective geraniol production with minimized endogenous dehydrogenation.
abstract: Geraniol, a monoterpene alcohol, has versatile applications in the fragrance industry, pharmacy and agrochemistry. Moreover, geraniol could be an ideal gasoline alternative. In this study, recombinant overexpression of geranyl diphosphate synthase and the bottom portion of a foreign mevalonate pathway in Escherichia coli MG1655 produced 13.3mg/L of geraniol. Introduction of Ocimum basilicum geraniol synthase increased geraniol production to 105.2mg/L. However, geraniol production encountered a loss from its endogenous dehydrogenization and isomerization into other geranoids (nerol, neral and geranial). Three E. coli enzymes (YjgB, YahK and YddN) were identified with high sequence identity to plant geraniol dehydrogenases. YjgB was demonstrated to be the major one responsible for geraniol dehydrogenization. Deletion of yjgB increased geraniol production to 129.7mg/L. Introduction of the whole mevalonate pathway for enhanced building block synthesis from endogenously synthesized mevalonate improved geraniol production up to 182.5mg/L in the yjgB mutant after 48h of culture, which was a double of that obtained in the wild type control (96.5mg/L). Our strategy for improving geraniol production in engineered E. coli should be generalizable for addressing similar problems during metabolic engineering.
authors.affiliation: Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Chonglong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Sang-Hwal
authors.initials: SH
authors.lastname: Yoon
authors.affiliation: Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Hui-Jeong
authors.initials: HJ
authors.lastname: Jang
authors.affiliation: Industrial Biotechnology Research Center, KRIBB, Daejeon 305-806, Republic of Korea. Electronic address: choi4162@kribb.re.kr.
authors.forename: Eui-Sung
authors.initials: ES
authors.lastname: Choi
authors.affiliation: Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea. Electronic address: swkim@gnu.ac.kr.
authors.forename: Seon-Won
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000080462:Acyclic Monoterpenes; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D051231:Farnesyltranstransferase / Q000235:genetics / Q000378:metabolism; D055786:Gene Knockout Techniques; D006865:Hydrogenation; D018649:Ocimum basilicum / Q000201:enzymology / Q000235:genetics; D015202:Protein Engineering; D013729:Terpenes / Q000378:metabolism*
chemical_list: D000080462:Acyclic Monoterpenes; D013729:Terpenes; D051231:Farnesyltranstransferase; C007836:geraniol
keywords: E. coli; Geraniol; Geraniol dehydrogenation; Mevalonate pathway; Monoterpene