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 intea-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.

Gordonia cholesterolivorans sp. nov., a cholesterol-degrading actinomycete isolated from sewage sludge

“…Most of the morphological, physiological and chemotaxonomic characteristics of strain Chol-3 T were consistent with the diagnostic properties of the type strains of the genus Gordonia (Stackebrandt et al, 1988;Goodfellow & Maldonado, 2006). Strain Chol-3 T shows an elementary branching rod-coccus growth cycle that is commonly found among strains of the genus Gordonia.…”

Transfer of Rhodococcus aichiensis Tsukamura 1982 and Nocardia amarae Lechevalier and Lechevalier 1974 to the Genus Gordona as Gordona aichiensis comb. nov. and Gordona amarae comb. nov.

“…Furthermore, the sizes of the mycolic acids of R. aichiensis DSM 43978T and N. amarae DSM 43392T are similar to the sizes of the mycolic acids found in members of the genus Gordona (3, 29) (Table l), although pyrolytic cleavage of methyl mycolates of N. amarae DSM 43392T releases unusual monounsaturated esters (5,16) that are unique to this species within the family Nocardiuceae. Nevertheless, as shown in Table 1, the combined chemotaxonomic characteristics of R. aichiensis DSM 43978T and N. arnarae DSM 43392T suggest that these organisms are closely related to the genus Gordona (25). Therefore, almost complete 16s rDNA sequences (>1,500 nucleotides) were determined for N. amarae DSM 43392T, R. aichiensis DSM 43978T, G. bronchialis DSM 43247T, Fig.…”

“…Although such investigations have revealed several morphological and chemical markers that distinguish members of this suprageneric group (18,(24)(25)(26), which comprises the genera C o y ebacterium, Gordona, Mycobacterium, Nocardia, Rhodococcus, and Tsukamurella, there are still a few taxa whose classification is uncertain. Two such taxa, Nocardia amarae (16) and Rhodococcus aichiensis (27), have been retained in the genera Nocardia and Rhodococcus, respectively; however, the current affiliations of these species are in some respects contradictory to the diagnostic characteristics of the respective type species.…”

Biodegradation of melamine and its hydroxy derivatives by a bacterial consortium containing a novel Nocardioides species

“…Another melamine-degrading isolate, Rhodococcus corallinus strain 11 (NRRL B-15444R), was obtained from soils that had been experimentally exposed to s-triazine herbicides for a long time (Cook and Hütter 1984;Cook 1987). R. corallinus was originally considered to be a junior synonym of Rhodococcus rubropertinctus in a DNA homology study (Mordarski et al 1980), and has since been reclassified as Gordonia rubripertincta (Stackebrandt et al 1988;Euzeby 1998). Genes encoding enzymes for melamine deamination, trzA for s-triazine hydrolase (TrzA) and triA for melamine deaminase (TriA), were cloned from G. rubripertincta strain NRRL B-15444R and A. citrulli strain NRRL B-12227, respectively (Shao et al 1995;Seffernick et al 2001).…”