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[Generic interrelations of purple bacteria in the genus Rhodopseudomonas]
Mikrobiologiia
|March 1, 1984
Summary
DNA-DNA hybridization reveals genetic relationships among purple nonsulfur bacteria. Rhodospirillum and Rhodopseudomonas species show moderate homology, while Rhodomicrobium is distantly related, indicating significant strain divergence within R. sphaeroides.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Purple nonsulfur bacteria (family Rhodospirillaceae) are ecologically significant phototrophs.
- Understanding their evolutionary relationships is crucial for bacterial taxonomy and phylogeny.
Purpose of the Study:
- To investigate the phylogenetic relationships among genera within the Rhodospirillaceae family.
- To assess the intraspecific genetic diversity of Rhodopseudomonas sphaeroides strains.
Main Methods:
- DNA-DNA hybridization was employed to quantify genetic relatedness.
- Thermal stability analysis of hybrid DNA duplexes was used to assess sequence divergence.
Main Results:
- Moderate DNA-DNA homology (8-17%) was observed between Rhodopseudomonas species and Rhodospirillum rubrum (13%) when compared to Rhodopseudomonas sphaeroides 8259.
- Rhodomicrobium vannielli exhibited low homology (3%) to R. sphaeroides 8259, suggesting a distant relationship.
- Analysis of thermal stability indicated significant divergence among different R. sphaeroides strains (delta T50 = 2.1-11.6).
Conclusions:
- The study provides insights into the evolutionary divergence within the Rhodospirillaceae family.
- Significant genetic heterogeneity exists among strains of Rhodopseudomonas sphaeroides, impacting their classification.