Abstract: The present invention relates to the genetic modification of bacteria of the genus Clostridium, typically solventogenic bacteria of the genus Clostridium, in particular bacteria possessing in the wild type a gene encoding an amphenicol-O-acetyltransferase. It thus relates to methods, tools and kits allowing such a genetic modification, in particular the removal or modification of a sequence encoding or controlling the transcription of an amphenicol-O-acetyltransferase, to the genetically modified bacteria obtained and to uses thereof, in particular for producing a solvent, preferably on an industrial scale.

Abstract: The present invention relates to the transformation and genetic modification of bacteria belonging to the phylum Firmicutes. It thus relates to methods, tools and kits allowing such genetic modification, involving in particular a nucleic acid sequence used to facilitate the transformation of the bacterium, said sequence comprising i) all or part of the sequence SEQ ID NO: 126 and ii) a sequence allowing the modification of the genetic material of a bacterium and/or expression, within said bacterium, of a DNA sequence partially or totally absent from the genetic material present within the wild-type version of said bacterium. The description also relates to the genetically modified bacteria obtained and uses thereof, in particular for producing a solvent, preferably on an industrial scale.