Oxalobacter paraformigenes is a Gram negative, non-spore-forming, oxalate-degrading anaerobic bacterium that was first isolated from human fecal samples.

[1] Based on fatty acid profile, 16S ribosomal RNA sequencing, and DNA probes specific to the oxc (oxalyl-CoA decarboxylase) gene and frc (formyl-CoA transferase), O. paraformigenes strain HOxBLS was considered a group II strain.

[2][3][4][5] However, whole genome sequencing revealed that O. paraformigenes HOxBLS is a different species from O. formigenes and it was subsequently renamed.

[6] The new species name paraformigenes uses the parent species formigenes and adds the Greek prefix para meaning "beside",[7] owing to that for the longest time O. paraformigenes was the only group II strain with a full genome sequence and it was used to make genetic comparisons between group I strains (now known as O.

[1] Oxalate is supplemented at 20 – 100 mM (depending on desired cell density) and bacteria are grown at 37 °C for 24 – 48 hours.