Ralstonia Eutropha - Taxonomy

Taxonomy

R. eutropha has gone through a series of name changes. In the first half of the 20th century many microorganisms were isolated for their ability to utilize hydrogen. Hydrogen metabolizing chemolithotrophic organisms were clustered into the group Hydrogenomonas. R. eutropha was originally named Hydrogenomonas eutrophus because it fell under the Hydrogenomonas classification and was “well nourished and robust”. Some of the original H. eutrophus cultures isolated were by Bovell and Wilde. After characterizing cell morphology, metabolism and GC content, the Hydrogenomonas nomenclature was disbanded because it comprised many species of microorganisms. R. eutropha at this time was renamed Alcaligenes eutropha because it was a microorganism with degenerate peritrichous flagellation. Investigating pheynotype, lipid composition, fatty acid composition and 16S rRNA analysis, A. eutropha was found to belong to the genus Ralstonia and named Ralstonia eutropha. Upon further study of the Ralstonia genus, Ralstonia was found to comprise two phenotypically distinct clusters. The new genus Wautersia was created from one of these clusters which included R. eutropha. In turn R. eutropha was renamed Wautersia eutropha. Looking at DNA-DNA hybridization and phyenotype comparison with Cupriavidus necator, W. eutropha was found to be the same species as previously described C. necator. Because C. necator was named in 1987 far before the name change to R. eutropha and W. eutropha, the name C. necator was assigned to R. eutropha according to Rule 23a of the International Code of Nomenclature of Bacteria.