Summary auto-generated
Bacterial strain T1, isolated for its ability to degrade toluene under denitrifying conditions, was identified as Thauera aromatica through 16S rRNA sequencing, DNA-DNA hybridization, and phenotypic characterization. Strain T1 showed 76.5% DNA similarity to the type strain K172T of T. aromatica and 99.7% 16S rRNA sequence similarity. However, this study revealed important differences between T. aromatica strains and the type species T. selenatis, particularly in flagellar insertion patterns. While T. selenatis has polar monotrichous flagellation, T. aromatica strains displayed peritrichous or degenerately peritrichous flagellation. The two Thauera species also showed differences in nutritional properties and growth characteristics. Based on these findings, the authors proposed emending the genus Thauera definition to accommodate both polar and peritrichously flagellated bacteria. The authors suggest that future studies of additional aromatic-degrading denitrifiers may warrant creation of new genera, but conservatively maintained T1 and K172T within Thauera pending further analysis of related strains.
Key findings
- Strain T1 was identified as Thauera aromatica based on 16S rRNA sequencing (99.7% similarity to K172T) and DNA hybridization (76.5% similarity)
- T. aromatica strains display degenerately peritrichous or peritrichous flagellation, differing from the polar monotrichous flagellation of T. selenatis
- The genus Thauera definition was emended to include both polar monotrichous and peritrichously flagellated bacteria
- T. aromatica and T. selenatis show substantial genetic distance and differences in nutritional versatility and growth properties
- Multiple aromatic substrates were preferentially utilized by these strains under denitrifying rather than aerobic conditions
This summary was generated automatically from the article PDF and is not part of the original publication. Refer to the PDF for the authoritative text.
Abstract
Bacterial strain T1, originally isolated by P. J. Evans on the basis of its capacity for toluene degradation under denitrifying conditions, has been classified as Thauera aromatica. In a comprehensive study of strains of this species, it was found that the cells have a different type of flagellar insertion from that of cells of the type species of the genus, Thauera selenatis, suggesting the convenience of an emendation of the description of the genus Thauera. Further studies on a larger collection of strains with the above characteristics may serve in the future as the basis for the creation of a new generic designation.