title: Production of L-lactate in Leuconostoc citreum via heterologous expression of L-lactate dehydrogenase gene.
abstract: D-form lactate is often found in fermented foods and excessive dietary intake of D-lactate may cause metabolic stress in both infants and patients. Leuconostoc citreum is a major lactic acid bacterium that produces D-lactate in fermented foods. The aim of this study was to change the pyruvate carbon flux in L. citreum from D-lactate into L-lactate by heterologous expression of L-lactate dehydrogenase (ldhL) gene. For this, ldhL from Lactobacillus plantarum was cloned and introduced into L. citreum using a shuttle vector pLeuCM. In the transformant, ldhL was successfully transcribed and L-lactate dehydrogenase was expressed. As a consequence of transformation, the ratio between D- and L-isomers was changed due to the increment of L-lactate and the decrement of D-lactate, but no significant differences were found in total lactate concentration between the host and transformant cells. This is the first report of metabolic engineering in Leuconostoc by modulating the central carbon flux into health-favored way.
authors.affiliation: Department of Food Science and Technology, Research Center for Bioresource and Health, Chungbuk National University, Cheongju, South Korea.
authors.forename: Qing
authors.initials: Q
authors.lastname: Jin
authors.forename: Jee Yun
authors.initials: JY
authors.lastname: Jung
authors.forename: Yu Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Eom
authors.forename: So-Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Tae-Jip
authors.initials: TJ
authors.lastname: Kim
authors.forename: Nam Soo
authors.initials: NS
authors.lastname: Han
mesh_terms: D003001:Cloning, Molecular; D015870:Gene Expression; D005798:Genes, Bacterial; D007536:Isomerism; D007770:L-Lactate Dehydrogenase / Q000235:genetics* / Q000378:metabolism*; D019344:Lactic Acid / Q000096:biosynthesis* / Q000737:chemistry*; D048191:Lactiplantibacillus plantarum / Q000201:enzymology* / Q000235:genetics; D007934:Leuconostoc / Q000254:growth & development / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D014169:Transformation, Bacterial
chemical_list: D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase