title: Metabolic engineering of a novel muconic acid biosynthesis pathway via 4-hydroxybenzoic acid in Escherichia coli.
abstract: cis,cis-Muconic acid (MA) is a commercially important raw material used in pharmaceuticals, functional resins, and agrochemicals. MA is also a potential platform chemical for the production of adipic acid (AA), terephthalic acid, caprolactam, and 1,6-hexanediol. A strain of Escherichia coli K-12, BW25113, was genetically modified, and a novel nonnative metabolic pathway was introduced for the synthesis of MA from glucose. The proposed pathway converted chorismate from the aromatic amino acid pathway to MA via 4-hydroxybenzoic acid (PHB). Three nonnative genes, pobA, aroY, and catA, coding for 4-hydroxybenzoate hydrolyase, protocatechuate decarboxylase, and catechol 1,2-dioxygenase, respectively, were functionally expressed in E. coli to establish the MA biosynthetic pathway. E. coli native genes ubiC, aroF(FBR), aroE, and aroL were overexpressed and the genes ptsH, ptsI, crr, and pykF were deleted from the E. coli genome in order to increase the precursors of the proposed MA pathway. The final engineered E. coli strain produced nearly 170 mg/liter of MA from simple carbon sources in shake flask experiments. The proposed pathway was proved to be functionally active, and the strategy can be used for future metabolic engineering efforts for production of MA from renewable sugars.
authors.affiliation: Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, Singapore, Republic of Singapore.
authors.forename: Sudeshna
authors.initials: S
authors.lastname: Sengupta
authors.affiliation: Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, Singapore, Republic of Singapore sudhakar_jonnalagadda@ices.a-star.edu.sg.
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Jonnalagadda
authors.affiliation: Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, Singapore, Republic of Singapore.
authors.forename: Lakshani
authors.initials: L
authors.lastname: Goonewardena
authors.affiliation: Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, Singapore, Republic of Singapore.
authors.forename: Veeresh
authors.initials: V
authors.lastname: Juturu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D053898:Biosynthetic Pathways; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D060847:Metabolic Engineering; D010226:Parabens / Q000378:metabolism*; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010226:Parabens; C005939:muconic acid; C038193:4-hydroxybenzoic acid; D013011:Sorbic Acid