Gene essentiality in the solventogenic Clostridium acetobutylicum DSM 792

is a solventogenic, anaerobic, gram-positive bacterium that is commonly considered the model organism for studying acetone-butanol-ethanol fermentation. The need to produce these chemicals sustainably and with a minimal impact on the environment has revived the interest in research on this bacterium. The recent development of efficient genetic tools allows to better understand the physiology of this micro-organism, aiming at improving its fermentation capacities. Knowledge about gene essentiality would guide the future genetic editing strategies and support the understanding of crucial cellular functions in this bacterium. In this work, we applied a transposon insertion site sequencing method to generate large mutant libraries containing millions of independent mutants that allowed us to identify a core group of 418 essential genes needed for