| Abstract | Amoebae play an important ecological role as predators in microbial communities. They also serve as niche for bacterial replication, harbor endosymbiotic bacteria and have contributed to the evolution of major human pathogens. Despite their high diversity, marine amoebae and their association with bacteria are poorly understood. Here we describe the isolation and characterization of two novel marine amoebae together with their bacterial endosymbionts, tentatively named 'Candidatus Occultobacter vannellae' and 'Candidatus Nucleophilum amoebae'. While one amoeba strain is related to Vannella, a genus common in marine habitats, the other represents a novel lineage in the Amoebozoa. The endosymbionts showed only low similarity to known bacteria (85-88% 16S rRNA sequence similarity) but together with other uncultured marine bacteria form a sister clade to the Coxiellaceae. Using fluorescence in situ hybridization and transmission electron microscopy, identity and intracellular location of both symbionts were confirmed; one was replicating in host-derived vacuoles, whereas the other was located in the perinuclear space of its amoeba host. This study sheds for the first time light on a so far neglected group of protists and their bacterial symbionts. The newly isolated strains represent easily maintainable model systems and pave the way for further studies on marine associations between amoebae and bacterial symbionts. |
| Text | 339912 2015 10.1038/srep13381 ISI Web of Science WOS 000360035600002 Scopus 2 s2.0 84940056585 RITMARE Gammaproteobacteria Coastal lakes Marine amoebae with cytoplasmic and perinuclear symbionts deeply branching in the Gammaproteobacteria Schulz Frederik; Tyml Tomas; Pizzetti Ilaria; Dykova Iva; Fazi Stefano; Kostka Martin; Horn Matthias 1Department of Microbiology and Ecosystem Sience, University of Vienna, Althanstraße 14, A 1090 Vienna, Austria. 2Faculty of Science, University of South Bohemia, Brani ovska 31, 370 05 eske Bud jovice, Czech Republic. 3Institute of Parasitology, Biology Centre CAS, Brani ovska 31, 370 05 eske Bud jovice, Czech Republic. 4Department of Botany and Zoology, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic. 5Water Research Institute, National Research Council of Italy IRSA CNR , Via Salaria Km 29,300, 00015 Monterotondo Roma, Italy. Amoebae play an important ecological role as predators in microbial communities. They also serve as niche for bacterial replication, harbor endosymbiotic bacteria and have contributed to the evolution of major human pathogens. Despite their high diversity, marine amoebae and their association with bacteria are poorly understood. Here we describe the isolation and characterization of two novel marine amoebae together with their bacterial endosymbionts, tentatively named Candidatus Occultobacter vannellae and Candidatus Nucleophilum amoebae . While one amoeba strain is related to Vannella, a genus common in marine habitats, the other represents a novel lineage in the Amoebozoa. The endosymbionts showed only low similarity to known bacteria 85 88% 16S rRNA sequence similarity but together with other uncultured marine bacteria form a sister clade to the Coxiellaceae. Using fluorescence in situ hybridization and transmission electron microscopy, identity and intracellular location of both symbionts were confirmed; one was replicating in host derived vacuoles, whereas the other was located in the perinuclear space of its amoeba host. This study sheds for the first time light on a so far neglected group of protists and their bacterial symbionts. The newly isolated strains represent easily maintainable model systems and pave the way for further studies on marine associations between amoebae and bacterial symbionts. 5 Published version https //www.scopus.com/record/display.uri eid=2 s2.0 84940056585 origin=inward txGid=18245da433b1a41fed42cb869c4ba058 Marine amoebae with cytoplasmic and perinuclear symbionts deeply branching in the Gammaproteobacteria Schulz et al_2015_SREP.pdf Articolo in rivista Nature Publishing Group 2045 2322 Scientific reports Nature Publishing Group Scientific reports Nature Publishing Group Scientific reports Nature Publishing Group PIZZETTI ILARIA stefano.fazi FAZI STEFANO PB.P02.001.010 Progetto RITMARE IRSA CNR |
