Evidence of phylogenetic heterogeneity within the genus Rhodococcus: Revival of the genus Gordona (Tsukamura).

Abstract

Reverse transcriptase sequencing of 16S ribosomal ribonucleic acids of some representatives of the genus Rhodococcus were performed in an attempt to clarify their intra- and inter-generic relationships. The results indicate that the genus Rhodococcus as presently constituted is phylogenetically heterogeneous. On the basis of the 16S ribosomal-RNA sequence and earlier chemical data it is proposed that the genus Gordona (Tsukamura) be revived to accommodate those rhodococcal species containing relatively long-chain mycolic acids (48 to 66 carbon atoms) and MK-9(H2) as the predominant menaquinone type.