title: Revealing in vivo glucose utilization of Gluconobacter oxydans 621H Δmgdh strain by mutagenesis.
abstract: Gluconobacter oxydans, belonging to acetic acid bacteria, is widely used in industrial biotechnology. In our previous study, one of the main glucose metabolic pathways in G. oxydans 621H was blocked by the disruption of the mgdh gene, which is responsible for glucose oxidation to gluconate on cell membrane. The resulting 621H Δmgdh mutant strain showed an enhanced growth and biomass yield on glucose. In order to further understand the intracellular utilization of glucose by 621H Δmgdh, the functions of four fundamental genes, namely glucokinase-encoding glk1 gene, soluble glucose dehydrogenase-encoding sgdh gene, galactose-proton symporter-encoding galp1 and galp2 genes, were investigated. The obtained metabolic characteristics of 621H Δmgdh Δglk1 and 621H Δmgdh Δsgdh double-gene knockout mutants showed that, in vivo, glucose is preferentially phosphorylated to glucose-6-phosphate by glucokinase rather than being oxidized to gluconate by soluble glucose dehydrogenase. In addition, although the galactose-proton symporter-encoding genes were proved to be glucose transporter genes in other organisms, both galp genes (galp 1 and galp2) in G. oxydans were not found to be involved in glucose uptake system, implying that other unknown transporters might be responsible for transporting glucose into the cells.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 200237 Shanghai, China.
authors.forename: Liujing
authors.initials: L
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 200237 Shanghai, China.
authors.forename: Danni
authors.initials: D
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 200237 Shanghai, China.
authors.forename: Jilai
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 200237 Shanghai, China.
authors.forename: Jiajing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 200237 Shanghai, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Zhu
authors.affiliation: College of Life Science and Technology, Guangxi University, 100 Daxue Road, 530005 Nanning, Guangxi, China.
authors.forename: Liqin
authors.initials: L
authors.lastname: Du
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 200237 Shanghai, China. Electronic address: qhua@ecust.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Hua
mesh_terms: D004252:DNA Mutational Analysis; D017353:Gene Deletion; D020600:Gluconobacter oxydans / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D042843:Glucose 1-Dehydrogenase / Q000172:deficiency*; D053858:Metabolic Networks and Pathways / Q000235:genetics; D016296:Mutagenesis
chemical_list: D042843:Glucose 1-Dehydrogenase; D005947:Glucose
keywords: Galactose–proton symporter; Glucokinase; Gluconobacter oxydans; Glucose utilization; Soluble glucose dehydrogenase