FIG. 2.

Gene organization around oraS and oraE in complete sequenced genomes of 11 putative ornithine-fermenting bacteria (black) and in the sequence resources where the candidate genes have been cloned: the metagenomic contig MAA_MAB from an anaerobic digester of a wastewater treatment plant and the genome of ornithine-fermenting C. sticklandii (red). The symbol “//” indicates that the or-4 and or-5 genes are located elsewhere in the genome in these organisms. *, the draft genomes of eight additional C. difficile strains exhibit ornithine clusters which are identical to that in the completed 630 strain.