title: Phosphoenolpyruvate availability and the biosynthesis of shikimic acid.
abstract: The impact of increased availability of phosphoenolpyruvate during shikimic acid biosynthesis has been examined in Escherichia coli K-12 constructs carrying plasmid-localized aroF(FBR) and tktA inserts encoding, respectively, feedback-insensitive 3-deoxy-d-arabino-heptulosonic acid 7-phosphate synthase and transketolase. Strategies for increasing the availability of phosphoenolpyruvate were based on amplified expression of E. coli ppsA-encoded phosphoenolpyruvate synthase or heterologous expression of the Zymomonas mobilis glf-encoded glucose facilitator. The highest titers and yields of shikimic acid biosynthesized from glucose in 1 L fermentor runs were achieved using E. coli SP1.lpts/pSC6.090B, which expressed both Z. mobilis glf-encoded glucose facilitator protein and Z. mobilis glk-encoded glucose kinase in a host deficient in the phosphoenolpyruvate:carbohydrate phosphotransferase system. At 10 L scale with yeast extract supplementation, E. coli SP1.lpts/pSC6.090B synthesized 87 g/L of shikimic acid in 36% (mol/mol) yield with a maximum productivity of 5.2 g/L/h for shikimic acid synthesized during the exponential phase of growth.
authors.affiliation: Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, USA.
authors.forename: Sunil S
authors.initials: SS
authors.lastname: Chandran
authors.forename: Jian
authors.initials: J
authors.lastname: Yi
authors.forename: K M
authors.initials: KM
authors.lastname: Draths
authors.forename: Ralph
authors.initials: R
authors.lastname: von Daeniken
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Weber
authors.forename: J W
authors.initials: JW
authors.lastname: Frost
mesh_terms: D010723:3-Deoxy-7-Phosphoheptulonate Synthase / Q000235:genetics / Q000378:metabolism*; D001682:Biological Availability; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005818:Genetic Engineering / Q000379:methods*; D005947:Glucose / Q000378:metabolism*; D010728:Phosphoenolpyruvate / Q000378:metabolism*; D012765:Shikimic Acid / Q000378:metabolism*; D013045:Species Specificity; D014174:Transketolase / Q000235:genetics / Q000378:metabolism*
chemical_list: D012765:Shikimic Acid; D010728:Phosphoenolpyruvate; D014174:Transketolase; D010723:3-Deoxy-7-Phosphoheptulonate Synthase; D005947:Glucose