Marine Biology

, Volume 115, Issue 2, pp 179–185

Sulfide-oxidizing bacteria in the burrowing echinoid, Echinocardium cordatum (Echinodermata)

Authors

  • A. Temara
    • Laboratoire de Biologie marineUniversité Libre de Bruxelles
  • C. de Ridder
    • Laboratoire de Biologie marineUniversité Libre de Bruxelles
  • J. G. Kuenen
    • Kluyver Laboratory of BiotechnologyDelft University of Technology
  • L. A. Robertson
    • Kluyver Laboratory of BiotechnologyDelft University of Technology
Article

DOI: 10.1007/BF00346333

Cite this article as:
Temara, A., de Ridder, C., Kuenen, J.G. et al. Marine Biology (1993) 115: 179. doi:10.1007/BF00346333

Abstract

Symbiotic filamentous bacteria thrive in the intestinal caecum of the deposit-feeding echinoid Echinocardium cordatum. Specimens of E. cordatum were collected at Wimereux (Nord Pas-de-Calais, France) in 1991. Their symbiotic bacteria build nodules by forming multilayered mats around detrital particles that enter the caecum. The morphological features of the bacteria are those of Thiothrix, a sulfide-oxidizing genus. The filaments, which may form rosettes, are sheathed and made by a succession of hundreds of rod-shaped bacteria which store elemental sulfur in the presence of external sulfide. Live bacteria are restricted to the outer layers of the nodules. Their sulfide-oxidizing activity was investigated, using a Biological Oxygen Monitor, by measuring the O2-consumption when reduced sulfur compounds are provided. They oxidize thiosulfate and sulfide. Optimal sulfide oxidation occurs at intermediary pO2 (100 to 160 μM O2l-1). Spectrophotometry has confirmed that the sulfur content of the filamentous symbiotic sulfideoxidizing bacteria depends on the presence of external sulfide. This is the first report of symbiotic intradigestive Thiothrixspp.-like bacteria; it lengthens the list of symbioses between sulfide-oxidizing bacteria and invertebrates from sulfide-rich habitats.

Copyright information

© Springer-Verlag 1993