supplementary data

Myxobacteria are Gram-negative, spore-forming predatory bacteria isolated from diverse environmental samples that feed on other microbes for their survival and growth . However, no reports of cultured representatives from the human gut have been published to date, although previous investigations have revealed the presence of myxobacterial operational taxonomic units (OTU's) in skin and faecal samples. In this study, three myxobacterial strains designated as O35, O15 and Y35 were isolated and purified from faecal samples of two inflammatory bowel disease (IBD) patients. The 16S rRNA gene sequence analysis and phylogeny identified the strains as Myxococcus spp. belonging to two different clades. Genome based phylogeny and overall genome related indices, i.e. average amino acid identity and percentage of conserved proteins confirmed the heterogeneity within the genus and placed the 3 strains within two different clades separated at the level of different genera. Digital DNA hybridization and average nucleotide identity values indicated that they belonged to two novel Myxococcus spp. The analysis of meta-barcoding data from IBD and control cohorts detected OTU lineages closely affiliated to the three novel strains. Based on evidence from detailed structural and functional genomics we propose the novel species Myxococcus faecalis sp. nov. O35T and a new genus Pseudomyxococcus gen. nov. to accommodate the novel species Pseudomyxococcus flavus sp. nov. Y35T