Clostridium beijerinckii NRRL B-598 is a sporulating, butanol and hydrogen producing strain that utilizes carbohydrates by the acetone-butanol-ethanol (ABE) fermentative pathway. The pathway consists of two metabolic phases, acidogenesis and solventogenesis, from which the latter one can be coupled with sporulation. Thorough transcriptomic profiling during a complete life cycle and both metabolic phases completed with flow cytometry, microscopy and a metabolites analysis helped to find out key genes involved in particular cellular events. The description of genes/operons that are closely involved in metabolism or the cell cycle is a necessary condition for metabolic engineering of the strain and will be valuable for all C. beijerinckii strains and other Clostridial species. The study focused on glucose transport and catabolism, hydrogen formation, metabolic stress response, binary fission, motility/chemotaxis and sporulation, which resulted in the composition of the unique image reflecting clostridial population changes. Surprisingly, the main change in expression of individual genes was coupled with the sporulation start and not with the transition from acidogenic to solventogenic metabolism. As expected, solvents formation started at pH decrease and the accumulation of butyric and acetic acids in the cultivation medium.

Department of Biomedical Engineering Brno University of Technology Technicka 12 616 00 Brno Czech Republic

Department of Biotechnology University of Chemistry and Technology Prague Technicka 5 166 28 Prague Czech Republic

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Identification and Validation of Reference Genes in Clostridium beijerinckii NRRL B-598 for RT-qPCR Using RNA-Seq Data

Deeper below the surface-transcriptional changes in selected genes of Clostridium beijerinckii in response to butanol shock

Changes in efflux pump activity of Clostridium beijerinckii throughout ABE fermentation

Transcriptional analysis of amino acid, metal ion, vitamin and carbohydrate uptake in butanol-producing Clostridium beijerinckii NRRL B-598

A transcriptional response of Clostridium beijerinckii NRRL B-598 to a butanol shock