Archives of Microbiology

, Volume 169, Issue 2, pp 129–135

Physiology and tactic response of the phototrophic consortium “Chlorochromatium aggregatum”

  • Jürgen M. Fröstl
  • J. Overmann
Original paper

DOI: 10.1007/s002030050552

Cite this article as:
Fröstl, J. & Overmann, J. Arch Microbiol (1998) 169: 129. doi:10.1007/s002030050552

Abstract

The phototrophic consortium “Chlorochromatium aggregatum” was enriched from sediment samples of a eutrophic freshwater lake and was maintained at high numbers in anoxic sulfide-reduced medium. Growth of intact consortia was observed only in the light and in the presence of 2-oxoglutarate as an organic carbon source. Consortia of “C. aggregatum” reached maximum growth rates at light intensities ≥ 5 μmol quanta m–2 s–1. Of ten compounds tested, sulfide, thiosulfate, 2-oxoglutarate, and citrate served as a chemoattractant for “C. aggregatum”. When incubated in the presence of sulfide and in the light, epibionts reduced the fluorochrome 5-cyano-2,3-di-4-tolyl-tetrazolium chloride (CTC). Reduction of CTC was not observed in the presence of the uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) or in the dark, indicating that sulfide serves as an electron donor for the phototrophic epibiont. Motile consortia accumulated scotophobically in microcuvettes at a wavelength of 740 nm. Since this wavelength corresponds to the position of the absorption maximum of bacteriochlorophylls c or d, the photosynthetic pigments are most likely the photoreceptors of the scotophobic response. It is concluded that, within the consortia, a rapid interspecies signal transfer occurs between the nonmotile, green-colored epibiont and the motile, colorless central bacterium.

Key words Phototrophic consortia “Chlorochromatium” Syntrophy Phototaxis Chemotaxis 

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Jürgen M. Fröstl
    • 1
  • J. Overmann
    • 1
  1. 1.Paläomikrobiologie, Institut für Chemie und Biologie des Meeres, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg, Germany Tel. +49-441-970-6376; Fax +49-441-798-3583 e-mail: j.overmann@palmikro.icbm.uni-oldenburg.deDE