Fig. 2

Inovirus virions are detectable and visible in in vitro cultures of Enterocloster strains. qPCR assay using A pI and B 16S rRNA gene-specific primers in supernatants of centrifuged stable phase Enterocloster cultures (untreated) that were filter-sterilized and DNase digested (treated). Data shown for three biological replicates. Cq – quantification cycle, higher Cq values indicate lower concentration in the sample. After removal of unprotected DNA via DNAse treatment (Methods) bacterial 16S rRNA is not detectable (Cq value above No template control), while inovirus pI gene is. C Negative stain transmission electron micrograph generated from concentrated and purified cell-free spent media supernatants of stable phase Enterocloster growth cultures. Specimens were stained with 1% uranyl acetate. Micrographs show filamentous morphologies with a diameter of ~ 6–8 nm and a length of ~ 600–800 nm