title: Roles of export genes cgmA and lysE for the production of L-arginine and L-citrulline by Corynebacterium glutamicum.
abstract: L-arginine is a semi-essential amino acid with application in cosmetic, pharmaceutical, and food industries. Metabolic engineering strategies have been applied for overproduction of L-arginine by Corynebacterium glutamicum. LysE was the only known L-arginine exporter of this bacterium. However, an L-arginine-producing strain carrying a deletion of lysE still accumulated about 10 mM L-arginine in the growth medium. Overexpression of the putative putrescine and cadaverine export permease gene cgmA was shown to compensate for the lack of lysE with regard to L-arginine export. Moreover, plasmid-borne overexpression of cgmA rescued the toxic effect caused by feeding of the dipeptide Arg-Ala to lysE-deficient C. glutamicum and argO-deficient Escherichia coli strains. Deletion of the repressor gene cgmR improved L-arginine titers by 5 %. Production of L-lysine and L-citrulline was not affected by cgmA overexpression. Taken together, CgmA may function as an export system not only for the diamine putrescine and cadaverine but also for L-arginine. The major export system for L-lysine and L-arginine LysE may also play a role in L-citrulline export since production of L-citrulline was reduced when lysE was deleted and improved by 45 % when lysE was overproduced.
authors.affiliation: Faculty of Biology and CeBiTec, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
authors.forename: Dorit
authors.initials: D
authors.lastname: Lubitz
authors.affiliation: Faculty of Biology and CeBiTec, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
authors.forename: João M P
authors.initials: JM
authors.lastname: Jorge
authors.affiliation: Faculty of Biology and CeBiTec, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
authors.forename: Fernando
authors.initials: F
authors.lastname: Pérez-García
authors.affiliation: Faculty of Biology and CeBiTec, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
authors.forename: Hironori
authors.initials: H
authors.lastname: Taniguchi
authors.affiliation: Faculty of Biology and CeBiTec, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany. volker.wendisch@uni-bielefeld.de.
authors.forename: Volker F
authors.initials: VF
authors.lastname: Wendisch
mesh_terms: D026923:Amino Acid Transport Systems, Basic / Q000235:genetics / Q000378:metabolism*; D001120:Arginine / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002956:Citrulline / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015870:Gene Expression
chemical_list: D026923:Amino Acid Transport Systems, Basic; D001426:Bacterial Proteins; C104616:LysE protein, Corynebacterium glutamicum; D002956:Citrulline; D001120:Arginine
keywords: Amino acid exporters; ArgO; C. glutamicum; CgmA; E. coli; L-arginine; L-citrulline; L-lysine; LysE