Clostridium culturomicium sp. nov. and Clostridium jeddahitimonense sp. nov., novel members of the Clostridium genus isolated from the stool of an obese Saudi Arabian.

Taxono-genomics is an innovative concept coined for the description of new bacterial species. Phenotypic characteristics were combined with a genomic approach to describe two new species within the Clostridium senso stricto genus: Clostridium culturomicium strain CL-6T and Clostridium jeddahitimonense strain CL-2T, both isolated from the gut microbiota of an obese man from Saudi Arabia. Strains CL-6T and CL-2T shared a similarity of 98.4% with the 16S rRNA gene of Clostridium subterminale strain JCM 1417T (accession number NR113027) and 98% with that of Clostridium disporicum strain DS1T (accession number NR026491), respectively. The highest OrthoANI values were shared with Clostridium punense for strain CL-6T (70.8%) and with Clostridium disporicum for strain CL-2T (87.1%). Additionally, strain CL-6T and strain CL-2T shared a 16S rRNA similarity of 91.4%. Both strains were anaerobic, spore-forming and Gram-stain-positive non-motile bacilli. The genome of Clostridium culturomicium strain CL-6T is 4,325,182 bp long with 32.2% GC content. As for Clostridium jeddahitimonense strain CL-2T, the genome is 4,074,758 bp long with 29.2% GC content.