title: Genetic replacement of tesB with PTE1 affects chain-length proportions of 3-hydroxyalkanoic acids produced through β-oxidation of oleic acid in Escherichia coli.
abstract: Acyl-CoA thioesterase II (TesB), which catalyzes hydrolysis of acyl-CoAs to free fatty acids and CoA, is involved in 3-hydroxyalkanoic acid production in Escherichia coli. Effects of genetic replacement of tesB with Saccharomyces cerevisiae acyl-CoA thioesterase gene PTE1 on 3-hydroxyalkanoic acid production from oleic acid through β-oxidation were examined. Kinetic analyses using β-oxidation intermediates showed that hydrolyses of C4-acyl substrates are more efficient by PTE1 than by TesB. Deletion of tesB in E. coli decreased 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, and hexanoic acid in medium after cultivation with oleic acid as a sole carbon source. Hexanoic acid concentration was much lower than those of 3-hydroxyacids. In genetic complementation of tesB deletion, use of PTE1, instead of tesB, affected proportions of the 3-hydroxyalkanoic acids. Proportion of 3-hydroxybutyric acid was higher in a PTE1-complemented strain than in a tesB-complemented strain, while proportions of 3-hydroxyhexanoic acid and 3-hydroxyoctanoic acid markedly increased in the tesB-complemented strain. Proportion of 3-hydroxyoctanoic acid did not significantly increase in the PTE1-complemented strain. These data indicate possibilities of 3-hydroxyalkanoic acid production from oleic acid through β-oxidation and customization of their chain-length proportions by genetic replacement of tesB with a gene encoding acyl-CoA thioesterase with a different kinetic property.
authors.affiliation: Department of Bioproductive Science, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya 321-8505, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Seto
authors.forename: Junkyu
authors.initials: J
authors.lastname: Kang
authors.forename: Li
authors.initials: L
authors.lastname: Ming
authors.forename: Naoto
authors.initials: N
authors.lastname: Habu
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Nihei
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Ueda
authors.forename: Isamu
authors.initials: I
authors.lastname: Maeda
mesh_terms: D000473:Alkanes / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005816:Genetic Complementation Test; D007700:Kinetics; D019301:Oleic Acid / Q000378:metabolism*; D010084:Oxidation-Reduction; D013869:Thiolester Hydrolases / Q000235:genetics / Q000378:metabolism*; D014867:Water / Q000737:chemistry
chemical_list: D000473:Alkanes; D014867:Water; D019301:Oleic Acid; D013869:Thiolester Hydrolases