Morphological,Physiological, and Molecular Characterization of a Newly Isolated Steroid-Degrading Actinomycete,Identified as <Emphasis Type="Italic">Rhodococcus ruber</Emphasis> Strain Chol-4 |
| |
Authors: | Laura Fernández de las Heras Esther García Fernández J María Navarro Llorens Julián Perera Oliver Drzyzga |
| |
Institution: | 1.Departamento de Bioquímica y Biología Molecular I,Universidad Complutense de Madrid,Madrid,Spain |
| |
Abstract: | The aerobic degradation of cholesterol, testosterone, androsterone, progesterone, and further steroid compounds as sole carbon
source has been observed in the newly isolated bacterial Gram-positive strain Chol-4. The 16S rRNA gene sequence shares the
greatest similarity with members of the genus Rhodococcus, with the closest shared nucleotide identities of 98–99% with Rhodococcus
ruber (DSM 43338T) and Rhodococcus
aetherivorans (DSM 44752T). Phylogenetic analysis of Rhodococcus 16S rRNA gene sequences consistently places strain Chol-4 in a clade shared with those both type strains within the Rhodococcus rhodochrous subclade. The results of DNA–DNA hybridization against its two phylogenetically closest neighbors as well as the results
of morphological, physiological, and biochemical tests allowed genotypic and phenotypic differentiation of strain Chol-4 from
Rhodococcus
ruber (DSM 43338T) on the species level and from the other validly described Rhodococcus species on the genus level. Strain Chol-4 therefore merits recognition as a novel strain of the species Rhodococcus
ruber and demonstrates for the first time the capability of this species to utilize a great variety of steroid compounds as growth
substrates never shown for other species of this genus so far. The genome of strain Chol-4 harbors at least one gene cluster
that may be responsible for the degradation of steroid compounds. This gene cluster was identified in a cloned 5458 bp BamHI–EcoRV DNA fragment and compared to similar genes from other Gram-positive and Gram-negative bacteria described so far. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|