title: Pyruvate production using engineered Escherichia coli.
abstract: Pyruvate plays an essential role in the central carbon metabolism of multiple organisms and is used as a raw material in the chemical, biochemical and pharmaceutical industries. To meet demand, large amounts of pyruvate are produced through fermentation processes. Here we describe a simple and efficient method for producing pyruvate in Escherichia coli. To stop carbon flux from pyruvate to fatty acids, the accBC genes, which encode the enzyme that catalyzes the first step of fatty acid biosynthesis and is essential for vegetative growth, were manipulated within the genome; its native promoter was replaced with the tetracycline (or doxycycline)-regulated promoter and the corresponding transcriptional regulator genes. The resulting strain grew normally in the presence of doxycycline, but showed poor growth upon withdrawal of doxycycline. Using this strain, we developed a high pyruvate producing strain (strain LAFCPCPt-accBC-aceE), in which the tetracycline-regulated promoter was also introduced upstream of aceE, and the ackA-pta, adhE, cra, ldhA, pflB and poxB genes were deleted. After determining the optimal culture conditions for this strain, the final pyruvate concentration reached 26.1 g L-1after 72 h with a theoretical yield of 55.6 %. These levels are high enough to indicate that the developed strain has the potential for application to industrial production of pyruvate.
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-0046, Japan.
authors.forename: Hironaga
authors.initials: H
authors.lastname: Akita
authors.affiliation: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, 062-8517, Japan. nnakashima@bio.titech.ac.jp.|Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1-M6-5 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan. nnakashima@bio.titech.ac.jp.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Nakashima
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-0046, Japan.|Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, 062-8517, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Hoshino
keywords: Doxycycline; Escherichia coli; Fermenter; Promoter regulation; Pyruvate; Tetracycline