Solirubrobacter pauli gen. nov., sp nov., a mesophilic bacterium within the Rubrobacteridae related to common soil clones

A novel bacterium, strain B33D1(T), isolated from agricultural soil, was characterized taxonomically and phylogenetically. Strain B33D1(T) was a Gram-positive, aerobic rod of medium length that formed long chains on a common laboratory medium. However, B33D1(T) grew poorly on the surface of agar plates and was sensitive to desiccation. The optimal growth temperature was 30degreesC (range 19-38degreesC). The organism grew well on a variety of sugars and was capable of utilizing a few amino acids as sole carbon sources. Phylogenetically, the most closely related described species to strain B33D1(T) was Rubrobacter xylanophilus, which possessed 86% 16S rRNA sequence similarity. However, a number of 16S rRNA gene clones derived from soil samples possessed up to 93% sequence similarity. These results placed strain B33D1(T) within the subclass Rubrobacteridae of the phylum Actinobacteria. The novel genus and species Solirubrobacter pauli gen. nov., sp. nov. is proposed, with strain B33D1(T) (=ATCC BAA-492(T) = DSM 14954(T)) as the type strain.