Abstract
The 16S rDNA sequences of nine strains of green sulfur bacteria (Chlorobiaceae) were determined and compared to the four known sequences of Chlorobiaceae and to sequences representative for all eubacterial phyla. The sequences of the Chlorobiaceae strains were consistent with the secondary structure model proposed earlier for Chlorobium vibrioforme strain 6030. Similarity values > 90.1% and Knuc values < 0.11 indicate a close phylogenetic relatedness among the green sulfur bacteria. As a group, these bacteria represent an isolated branch within the eubacterial radiation. In Chlorobiaceae, a similar morphology does not always reflect a close phylogenetic relatedness. While ternary fission is a morphological trait of phylogenetic significance, gas vesicle formation occurs also in distantly related species. Pigment composition is not an indicator of phylogenetic relatedness since very closely related species contain different bacteriochlorophylls and carotenoids. Two different molecular fingerprinting techniques for the rapid differentiation of Chlorobiaceae species were investigated. The 16S rDNA fragments of several species could not be separated by denaturing gradient gel electrophoresis. In contrast, all strains investigated during the present work gave distinct banding patterns when dispersed repetitive DNA sequences were used as targets in PCR. The latter technique is, therefore, well suited for the rapid screening of isolated pure cultures of green sulfur bacteria.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.