caa a22 4500 60621335X CHVBK 20210128101047.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s10295-015-1689-3 doi (NATIONALLICENCE)springer-10.1007/s10295-015-1689-3 Control of carbon flux to glutamate excretion in Klebsiella pneumoniae [Elektronische Daten] the role of the indigenous plasmid and its encoded isocitrate dehydrogenase [Mansi El-Mansi, Francois Trappey, Ewan Clark, Malcolm Campbell] Klebsiella pneumoniae (NCTC, CL687/80) harbors a large indigenous plasmid (pC3), which in addition to encoding for citrate utilization, proline synthesis and glutamate excretion, it uniquely carries the structural gene (icd); encoding isocitrate dehydrogenase (ICDH). Flux analysis revealed that ICDH, despite its role in the generation of NADPH required for glutamate dehydrogenase, is not rate-limiting (controlling) in central metabolism as evidenced by a negative flux control coefficient and an adverse effect of overexpression (14-fold) on glutamate excretion. More significantly, however, this paper presents, for the first time, clear evidence that the accumulation of glutamate and its subsequent excretion is associated with the C3 plasmid-encoded regulatory elements, which trigger a shift-down in the activity of α-ketoglutarate dehydrogenase, both in the K. pneumoniae parental strain as well as in the E. coli exconjugants strains. This finding opens the door for the exploitation of regulatory elements as a tool for manipulating flux in microbial cell factories. Society for Industrial Microbiology and Biotechnology, 2015 Klebsiella pneumoniae nationallicence Glutamate excretion nationallicence Isocitrate dehydrogenase nationallicence Glutamate dehydrogenase nationallicence α-Ketoglutarate dehydrogenase nationallicence El-Mansi Mansi Centre for Research and Innovation, Faculty of Science, Elizade University, Ilara Mokin, Akure, Nigeria aut Trappey Francois Department of Biology, Davidson College, Davidson, NC, USA aut Clark Ewan Institute of Cell Biology, University of Edinburgh, Darwin Building, Mayfield Rd, EH9 3JR, Edinburgh, Scotland, UK aut Campbell Malcolm Department of Biology, Davidson College, Davidson, NC, USA aut Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/11(2015-11-01), 1547-1556 1367-5435 42:11<1547 2015 42 10295 https://doi.org/10.1007/s10295-015-1689-3 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/s10295-015-1689-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- El-Mansi Mansi Centre for Research and Innovation, Faculty of Science, Elizade University, Ilara Mokin, Akure, Nigeria aut NATIONALLICENCE 700 1- Trappey Francois Department of Biology, Davidson College, Davidson, NC, USA aut NATIONALLICENCE 700 1- Clark Ewan Institute of Cell Biology, University of Edinburgh, Darwin Building, Mayfield Rd, EH9 3JR, Edinburgh, Scotland, UK aut NATIONALLICENCE 700 1- Campbell Malcolm Department of Biology, Davidson College, Davidson, NC, USA aut NATIONALLICENCE 773 0- Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/11(2015-11-01), 1547-1556 1367-5435 42:11<1547 2015 42 10295