Elimination of formate production in <i>Clostridium thermocellum</i> [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 664.8 Fruits and vegetables
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2015
• Mô tả vật lý: Size: p. 1263-1272 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 263637
• Chủ đề: 1. 09 biomass fuels; 2. 59 basic biological sciences; 3. Cellulosic ethanol; 4. Clostridium thermocellum; 5. Pyruvate:formate lyase

Tóm tắt

 We study the ability of <
 i>
 Clostridium thermocellum<
 /i>
  to rapidly degrade cellulose and ferment resulting hydrolysis products into ethanol makes it a promising platform organism for cellulosic biofuel production via consolidated bioprocessing. Currently, however, ethanol yield are far below theoretical maximum due to branched product pathways that divert carbon and electrons towards formate, H<
 sub>
 2<
 /sub>
 , lactate, acetate, and secreted amino acids. To redirect carbon and electron flux away from formate, pyruvate:formate lyase (pfl) and respective PFL-activating enzyme were deleted. Formate production in the resulting ?pfl strain was eliminated and acetate production decreased by 50% on both complex and defined medium. Growth rate of ?pfl decreased by 2.9-fold on defined medium and diauxic growth was observed on complex medium. Supplementation of defined medium with 2 mM formate restored ?pfl growth rate to 80% of the parent strain. Finally, we discuss the role of pfl in metabolic engineering strategies and C<
 sub>
 1<
 /sub>
  metabolism.