RT Journal Article SR Electronic(1) A1 Vannini, Claudia A1 Rosati, Giovanna A1 Verni, Franco A1 Petroni, GiulioYR 2004 T1 Identification of the bacterial endosymbionts of the marine ciliate Euplotes magnicirratus (Ciliophora, Hypotrichia) and proposal of ‘Candidatus Devosia euplotis’ JF International Journal of Systematic and Evolutionary Microbiology, VO 54 IS 4 SP 1151 OP 1156 DO https://doi.org/10.1099/ijs.0.02759-0 PB Microbiology Society, SN 1466-5034, AB This paper reports the identification of bacterial endosymbionts that inhabit the cytoplasm of the marine ciliated protozoon Euplotes magnicirratus. Ultrastructural and full-cycle rRNA approaches were used to reveal the identity of these bacteria. Based on analysis of 16S rRNA gene sequences, evolutionary trees were constructed; these placed the endosymbiont in the genus Devosia in the α-Proteobacteria. The validity of this finding was also shown by fluorescence in situ hybridization with a Devosia-specific oligonucleotide probe. Differences at the 16S rRNA gene level (which allowed the construction of a species-specific oligonucleotide probe) and the peculiar habitat indicate that the endosymbiont represents a novel species. As its cultivation has not been successful to date, the provisional name ‘Candidatus Devosia euplotis' is proposed. The species- and group-specific probes designed in this study could represent convenient tools for the detection of ‘Candidatus Devosia euplotis' and Devosia-like bacteria in the environment., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.02759-0