Phylogenetic assessment of culture collection strains of Thiobacillus thioparus, and definitive 16S rRNA gene sequences for T. thioparus, T. denitrificans, and Halothiobacillus neapolitanus

The 16S rRNA gene sequences of 12 strains of Thiobacillus thioparus held by diVerent culture collections have been compared. A deWnitive sequence for the reference type strain (Starkey; ATCC 8158T) was obtained. The sequences for four examples of the Starkey type strain were essentially identical, conWrming their sustained identity after passage through diVerent laboratories. One strain (NCIMB 8454) was reassigned as a strain of Halothiobacillus neapolitanus, and a second (NCIMB 8349) was a species of Thermithiobacillus. These two strains have been renamed in their catalog by the National Collection of Industrial and Marine Bacteria. The 16S rRNA gene sequence of the type strain of Halothiobacillus neapolitanus (NCIMB 8539T) was determined and used to conWrm the identity of other culture collection strains of this species. The reference sequences for the type strains of Thiobacillus thioparus and Halothiobacillus neapolitanus have been added to the online List of Prokaryotic Names with Standing in Nomenclature. Comparison of the 16S rRNA gene sequences available for strains of Thiobacillus denitriWcans indicated that the sequence for the type strain (NCIMB 9548T) should always be used