0434504 - BC 2015 RIV DE eng J - Článek v odborném periodiku
Dirren, S. - Salcher, Michaela M. - Blom, J. F. - Schweikert, M. - Posch, T.
Ménage-a-trois: The amoeba Nuclearia sp. from Lake Zurich with its ecto- and endosymbiotic bacteria.
Protist. Roč. 165, č. 5 (2014), s. 745-758. ISSN 1434-4610. E-ISSN 1618-0941
Institucionální podpora: RVO:60077344
Klíčová slova: bacteria-protist symbioses * ectosymbionts * endosymbionts * feeding * Nucleariidae * Paucibacter toxinivorans
Kód oboru RIV: DA - Hydrologie a limnologie
Impakt faktor: 3.045, rok: 2014 ; AIS: 0.983, rok: 2014
DOI: https://doi.org/10.1016/j.protis.2014.08.004

We present a fascinating triad relationship between a eukaryotic amoeba and its two bacterial symbionts. The morphological characteristics of the amoeba allowed for a confident assignment to the genus Nuclearia (Opisthokonta, Nucleariidae), but species identification resulted in an ambiguous result. Sequence analysis indicated an affiliation to the species N. thermophila, however, several morphological features contradict the original description. Amoebal isolates were cultured for several years with their preferred food source, the microcystin-producing harmful cyanobacterium Planktothrix rubescens. Symbioses of the amoeba with ecto- and endosymbiotic bacteria were maintained over this period. Several thousand cells of the ectosymbiont are regularly arranged inside a layer of extracellular polymeric substances produced by the amoeba. The ectosymbiont was identified as Paucibacter toxinivorans (Betaproteobacteria), which was originally isolated by enrichment with microcystins. We found indications that our isolated ectosymbiont indeed contributed to toxin-degradation. The endosymbiont (Gammaproteobacteria, 15-20 bacteria per amoeba) is enclosed in symbiosomes inside the host cytoplasm and represents probably an obligate symbiont. We propose the name “Candidatus Endonucleariobacter rarus” for this bacterium that was neither found free-living nor in a symbiotic association. Nucleariidae are uniquely suited model organisms to study the basic principles of symbioses between opisthokonts and prokaryotes.
Trvalý link: http://hdl.handle.net/11104/0238525