Phylogenomic Classification and Biosynthetic Potential of the Fossil Fuel-Biodesulfurizing Rhodococcus Strain IGTS8.

Rhodococcusstrain IGTS8 is the most extensively studied model bacterium for biodesulfurization of fossil fuels via the non-destructive sulfur-specific 4S pathway. This strain was initially assigned toRhodococcus rhodochrousand later toRhodococcus erythropolisthus making its taxonomic status debatable and reflecting the limited resolution of methods available at the time. In this study, phylogenomic analyses of the whole genome sequences of strain IGTS8 and closely related rhodococci showed thatR. erythropolisandRhodococcus qingshengiiare very closely related species, thatRhodococcusstrain IGTS8 is aR. qingshengiistrain and that several strains identified asR. erythropolisshould be re-classified asR. qingshengii. The genomes of strains assigned to these species contain potentially novel biosynthetic gene clusters showing that members of these taxa should be given greater importance in the search for new antimicrobials and other industrially important biomolecules. The plasmid-bornedszoperon encoding fossil fuel desulfurization enzymes was present inR. qingshengiiIGTS8 andR. erythropolisXP suggesting that it might be transferable between members of these species.