title: Increased glucose utilization and cell growth of Corynebacterium glutamicum by modifying the glucose-specific phosphotransferase system (PTSGlc) genes.
abstract: The phosphoenolpyruvate:glucose phosphotransferase system (PTSGlc) is the major pathway of glucose uptake in Corynebacterium glutamicum. This study investigated glucose consumption rate, cell growth, and metabolite changes resulting from modification of PTSGlc. The classical l-lysine producer C. glutamicum XQ-8 exhibited low glucose consumption, cell growth, and l-lysine production rates, whereas these parameters were significantly increased during cultivating on glucose plus maltose, through inactivation of SugR, or by overexpression of PTSGlcgenes. XQ-8sugR::cat/pDXW-8-ptsI exhibited the highest increase in glucose consumption, growth rate, and l-lysine production, followed by XQ-8sugR::cat/pDXW-8-ptsG. However, overexpression of ptsH had little effect on the above-mentioned factors. Although co-overexpression of ptsGHI led to the highest glucose consumption, growth rate, and final l-lysine production; the l-lysine production rate was lower than that of XQ-8sugR::cat/pDXW-8-ptsIH. In fed-batch fermentation, XQ-8sugR::cat/pDXW-8-ptsIH had a higher growth rate of 0.54 h-1to a dry cell mass of 66 g·L-1after 16 h, and had a higher l-lysine production rate of 159.2 g·L-1after 36 h. These results indicate that modification of the sugar transport systems improves amino acid production, especially for mutants obtained by repeated physical and (or) chemical mutagenesis. However, modification of these systems needs to be performed on a case-by-case basis.
authors.affiliation: a The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Xu
authors.affiliation: b OriGene Biotechnology Co., Ltd., 88 Meiliang Road, WuXi 214122, People's Republic of China.
authors.forename: Junlan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: a The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China.
authors.forename: Dongdong
authors.initials: D
authors.lastname: Liu
authors.affiliation: a The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D005285:Fermentation; D017930:Genes, Reporter; D005947:Glucose / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D008320:Maltose / Q000378:metabolism; D009154:Mutation; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D008320:Maltose; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase; D005947:Glucose; D008239:Lysine
keywords: Corynebacterium glutamicum; cell growth; croissance cellulaire; glucose consumption rate; glucose-specific phosphotransferase system; l-lysine production; production de l-lysine; système de phosphotransférase sélectif au glucose; taux de consommation du glucose