title: Comparison of different approaches to activate the glyoxylate bypass in Escherichia coli K-12 for succinate biosynthesis during dual-phase fermentation in minimal glucose media.
abstract: Two different approaches to activate the glyoxylate bypass in model Escherichia coli K-12 strains for succinate biosynthesis during dual-phase fermentation in minimal glucose media were examined. Inactivation of IclR and FadR, the transcriptional regulators of the aceBAK operon, were insufficient for the involvement of the glyoxylate bypass in anaerobic succinate biosynthesis by strains grown aerobically under glucose-abundant conditions. In contrast, the strains that constitutively expressed the aceEF-lpdA operon coding for the pyruvate dehydrogenase complex could partially synthesise succinate anaerobically via the glyoxylate bypass, even in the presence of intact regulators. The results suggest that the intensive acetyl-CoA formation in the strains constitutively expressing pyruvate dehydrogenase matches the physiological conditions that favour the activation of the glyoxylate bypass.
authors.affiliation: Research Institute for Genetics and Selection of Industrial Microorganisms, 1-st Dorozhniy pr., 1, 117545 Moscow, Russia. skorokhodova@genetika.ru
authors.forename: Alexandra Yu
authors.initials: AY
authors.lastname: Skorokhodova
authors.forename: Andrey Yu
authors.initials: AY
authors.lastname: Gulevich
authors.forename: Anastasiya A
authors.initials: AA
authors.lastname: Morzhakova
authors.forename: Rustem S
authors.initials: RS
authors.lastname: Shakulov
authors.forename: Vladimir G
authors.initials: VG
authors.lastname: Debabov
mesh_terms: D000693:Anaerobiosis; D003470:Culture Media / Q000737:chemistry; D048168:Escherichia coli K12 / Q000235:genetics* / Q000378:metabolism*; D005285:Fermentation; D015870:Gene Expression; D055786:Gene Knockout Techniques; D005947:Glucose / Q000378:metabolism; D006038:Glyoxylates / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D011768:Pyruvate Dehydrogenase Complex / Q000096:biosynthesis / Q000235:genetics; D019802:Succinic Acid / Q000378:metabolism*
chemical_list: D003470:Culture Media; D006038:Glyoxylates; D011768:Pyruvate Dehydrogenase Complex; D019802:Succinic Acid; D005947:Glucose; C031150:glyoxylic acid