Symbioses between marine nematodes and sulfur-oxidizing chemoautotrophic bacteria

Autor(en)

Jörg Ott, Monika Bright, Silvia Bulgheresi

Abstrakt

Over the course of evolutionary history nematodes and sulfur-oxidizing chemoautotrophic bacteria have formed symbiotic relationships in marine sediments on at least two independent occasions. Mouthless worms of the genus Astomonema have endosymbionts which live intracellularly or extracellularly in the gut rudiment of their host. The ultrastructure of the bacteria and the ecology of the symbiosis are strong indications for a chemoautotrophic nature of the microorganisms; the lack of feeding structures in the host suggests a nutritive dependence on the microbes. In the Stilbonematinae, bacteria cover the outside of the body in a characteristic, species-specific pattern. Ultrastructure, incorporation of inorganic carbon and the presence of RuBisCo and key enzymes of sulfide oxidation pathways show the bacteria to be sulfur-oxidizing chemolithoautotrophs. Stable isotope analysis suggests that the worms depend on the bacteria for their nutrition. In turn, they provide the microorganisms with sulfide and oxygen by repeatedly migrating through the chemocline in sheltered sediments.

Organisation(en)

Journal

Symbiosis

Band

36

Seiten

103-126

Anzahl der Seiten

24

ISSN

0334-5114

Publikationsdatum

2004

Peer-reviewed

Ja

ÖFOS 2012

1060 Biologie

Sustainable Development Goals

SDG 14 – Leben unter Wasser

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/fb1d5fc8-ce35-4d8a-8c95-2cdcbba08d14