Phylogenetic Evidence for the Transfer of Caseobacter polymorphus (Crombach) to the Genus Corynebacterium

Reverse transcriptase sequencing of 16S ribosomal ribonucleic acid of Caseobacter polymorphus was performed in order to determine the relationship of this organism to other mycolic acid-containing actinomycetes and coryneform bacteria. The sequence data clearly demonstrate that Caseobacter polymorphus is a member of the genus Corynebacterium. Furthermore, Caseobacter polymorphus showed 100% sequence homology in a large stretch of 1,458 nucleotides with Corynebacterium variabilis. On the basis of the present and previous data we formally propose that Caseobacter polymorphus be considered a subjective synonym of Corynebacterium variabilis.