caa a22 4500 606212183 CHVBK 20210128101041.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s10295-015-1644-3 doi (NATIONALLICENCE)springer-10.1007/s10295-015-1644-3 Elimination of formate production in Clostridium thermocellum [Elektronische Daten] [Thomas Rydzak, Lee Lynd, Adam Guss] The ability of Clostridium thermocellum 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 is far below theoretical maximum due to branched product pathways that divert carbon and electrons towards formate, H2, lactate, acetate, and secreted amino acids. To redirect carbon and electron flux away from formate, genes encoding pyruvate:formate lyase (pflB) and PFL-activating enzyme (pflA) were deleted. Formate production in the resulting Δpfl strain was eliminated and acetate production decreased by 50% on both complex and defined medium. The growth rate of the Δpfl strain decreased by 2.9-fold on defined medium and biphasic growth was observed on complex medium. Supplementation of defined medium with 2mM formate restored Δpfl growth rate to 80% of the parent strain. The role of pfl in metabolic engineering strategies and C1 metabolism is discussed. The Author(s), 2015 Cellulosic ethanol nationallicence Clostridium thermocellum nationallicence Pyruvate:formate lyase nationallicence Metabolic engineering nationallicence C1 metabolism nationallicence Rydzak Thomas Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA aut Lynd Lee BioEnergy Science Center, Oak Ridge National Laboratory, One Bethel Valley Road Oak Ridge, 37831-6038, Tennessee, USA aut Guss Adam Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA aut Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/9(2015-09-01), 1263-1272 1367-5435 42:9<1263 2015 42 10295 https://doi.org/10.1007/s10295-015-1644-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10295-015-1644-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rydzak Thomas Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA aut NATIONALLICENCE 700 1- Lynd Lee BioEnergy Science Center, Oak Ridge National Laboratory, One Bethel Valley Road Oak Ridge, 37831-6038, Tennessee, USA aut NATIONALLICENCE 700 1- Guss Adam Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA aut NATIONALLICENCE 773 0- Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/9(2015-09-01), 1263-1272 1367-5435 42:9<1263 2015 42 10295