title: Increased riboflavin production by knockout of 6-phosphofructokinase I and blocking the Entner-Doudoroff pathway in Escherichia coli.
abstract: OBJECTIVE
  To construct an Escherichia coli strain capable of producing riboflavin with high titer and yield.
  
  
  RESULTS
  A low copy number plasmid pLS01 containing a riboflavin operon under the control of a constitutive promoter was constructed and introduced into Escherichia coli MG1655. Subsequently, the pfkA, edd and ead genes were disrupted, and the resulting strain LS02T produced 667 mg riboflavin/l in MSY medium supplied with 10 g glucose/l in flask cultivation. In a fed-batch process, riboflavin production of the strain reached 10.4 g/l with a yield of 56.8 mg riboflavin/g glucose.
  
  
  CONCLUSIONS
  To our knowledge, this is the first report of engineered E. coli strains that can produce more than 10 g riboflavin/l in fed-batch cultivation, indicating that E. coli has potential for riboflavin production.
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
authors.forename: Pei
authors.initials: P
authors.lastname: Kang
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. chentao@tju.edu.cn.|Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin, 300072, People's Republic of China. chentao@tju.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
mesh_terms: D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005285:Fermentation / Q000235:genetics / Q000502:physiology; D007218:Industrial Microbiology; D025221:Phosphofructokinases / Q000235:genetics* / Q000378:metabolism*; D012256:Riboflavin / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D025221:Phosphofructokinases; D012256:Riboflavin
keywords: Escherichia coli; Fed-batch fermentation; Metabolic engineering; Riboflavin