Rhodococcus phenolicus sp. nov., a novel bioprocessor isolated actinomycete with the ability to degrade chlorobenzene, dichlorobenzene and phenol as sole carbon sources

Abstract

The aerobic degradation of phenol, chlorobenzene and dichlorobenzene as a sole carbon source has been observed in bacterial Gram-positive strain G2P T isolated from a wastewater bioprocessor. Cells display branching mycelia fragmenting into rod and coccoid elements when grown on TSA. Aerial hyphae formation occurs when grown on phenol and chlorinated aromatics as the sole carbon source. Growth was observed at up to 0.75% phenol as a sole carbon source, indicating a strong tolerance for the compound. The 16S rRNA gene sequence shares the greatest similarity with members of the Rhodococcus genus, with the closest shared nucleotide identity of 98% with the aromatic toxin degrading bacteria Rhodococcus zopfii DSM 44108 T. Neighbor-joining and parsimony analysis of Corynebacterineae 16S rRNA gene sequences consistently places strain G2P T in a clade shared with R. zopfii within the Rhodococcus rhodochrous subclade. Based on a unique polyphasic profile involving phenotypic, ribosomal DNA sequence analysis, DNA–DNA hybridization, mol% DNA G+C content and fatty acid composition, G2P T is proposed to represent a previously uncharacterized, novel species in the genus Rhodococcus. The name Rhodococcus phenolicus is proposed for the isolate with the type strain G2P T (=DSM 44812) (=NRL B-24343).