Archives of Microbiology

, Volume 174, Issue 1–2, pp 50–58

Phylogenetic affiliation of the bacteria that constitute phototrophic consortia

  • Jürgen M. Fröstl
  • Jörg Overmann
Original Paper

DOI: 10.1007/s002030000172

Cite this article as:
Fröstl, J. & Overmann, J. Arch Microbiol (2000) 174: 50. doi:10.1007/s002030000172


The phylogenetic affiliation of epibionts occurring in three morphologically distinct types of green-colored phototrophic consortia was investigated. Intact consortia of the types "Chlorochromatium aggregatum", "C. glebulum", and a third previously undescribed type, tentatively named "C. magnum" were mechanically separated from accompanying bacteria by either micromanipulation or by chemotactic accumulation in sulfide-containing capillaries. A 540-base-pair-long fragment of the 16S rRNA gene of the epibionts was amplified employing PCR primers specific for green sulfur bacteria. DNA fragments were separated by denaturing gradient gel electrophoresis and subsequently sequenced. The results of this phylogenetic analysis indicated that the symbiotic epibionts, together with only a few free-living strains, form a cluster within the green sulfur bacterial radiation which is only distantly related to the majority of known representatives of this phylum. Consortia with identical morphology but different origin exhibited significant differences in their partial 16S rRNA gene sequences, which could be confirmed by analysis of the 16S rRNA secondary structure. The phylogenetic affiliation of the chemotrophic central rod-shaped bacterium of "C. aggregatum" and "C. magnum" was analyzed by fluorescent in situ hybridization. According to our results and contrary to earlier assumptions, the central bacterium is a member of the β-subgroup of the Proteobacteria.

Phototrophic consortia "Chlorochromatium" Green Sulfur bacteria β-Proteobacteria Micromanipulation Chemotaxis 

Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • Jürgen M. Fröstl
    • 1
  • Jörg Overmann
    • 1
  1. 1.Paläomikrobiologie, Institut für Chemie und Biologie des Meeres, Universität Oldenburg, Postfach 2503, 26111 Oldenburg, Germany

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