title: Metabolic Engineering of Escherichia coli for Poly(3-hydroxybutyrate) Production under Microaerobic Condition.
abstract: The alcohol dehydrogenase promoter PadhE and mixed acid fermentation pathway deficient mutants of Escherichia coli were employed to produce poly(3-hydroxybutyrate) (P3HB) under microaerobic condition. The E. coli mutant with ackA-pta, poxB, ldhA, and adhE deletions accumulated 0.67 g/L P3HB, up to 78.84% of cell dry weight in tube cultivation. The deletion of pyruvate formate-lyase gene pflB drastically decreased P3HB production and P3HB content to 0.09 g/L and 24.44%, respectively. Overexpressing pflB via the plasmid in its knocked out mutant restored cell growth and P3HB accumulation, indicating the importance of the pyruvate formate-lyase in microaerobic carbon metabolism. The engineered E. coli BWapld (pWYC09) produced 5.00 g/L P3HB from 16.50 g/L glucose in 24 h batch fermentation, and P3HB production yield from glucose was 0.30 g/g, which reached up to 63% of maximal theoretical yield.
authors.affiliation: Department of Basic Medicine, Medical College of Qinghai University, Xining 810016, China.
authors.forename: Xiao-Xing
authors.initials: XX
authors.lastname: Wei
authors.affiliation: Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Wei-Tao
authors.initials: WT
authors.lastname: Zheng
authors.affiliation: Department of Basic Medicine, Medical College of Qinghai University, Xining 810016, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Hou
authors.affiliation: College of Eco-Environmental Engineering of Qinghai University, Xining 810016, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liang
authors.affiliation: Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Zheng-Jun
authors.initials: ZJ
authors.lastname: Li
mesh_terms: D000332:Aerobiosis; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006885:Hydroxybutyrates / Q000378:metabolism*; D060847:Metabolic Engineering; D010957:Plasmids / Q000235:genetics; D011091:Polyesters / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D029968:Escherichia coli Proteins; D005947:Glucose; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates