The genus Tetrahymena (Ciliophora, Oligohymenophorea) probably represents the best studied ciliate genus. At present, more than forty species have been described. All are colorless, i.e. they do not harbor symbiotic algae, and as aerobes they need at least microaerobic habitats. Here, we present the morphological and molecular description of the first green representative, Tetrahymena utriculariae n. sp., living in symbiosis with endosymbiotic algae identified as Micractinium sp. (Chlorophyta). The full life cycle of the ciliate species is documented, including trophonts and theronts, conjugating cells, resting cysts and dividers. This species has been discovered in an exotic habitat, namely in traps of the carnivorous aquatic plant Utricularia reflexa (originating from Okavango Delta, Botswana). Green ciliates live as commensals of the plant in this anoxic habitat. Ciliates are bacterivorous, however, symbiosis with algae is needed to satisfy cell metabolism but also to gain oxygen from symbionts. When ciliates are cultivated outside their natural habitat under aerobic conditions and fed with saturating bacterial food, they gradually become aposymbiotic. Based on phylogenetic analyses of 18S rRNA and mitochondrial cox1 genes T. utriculariae forms a sister group to Tetrahymena thermophila.

• MeSH
• cévnaté rostliny parazitologie   MeSH
• Chlorophyta parazitologie   MeSH
• Ciliophora klasifikace   metabolismus   fyziologie   MeSH
• ekologie MeSH
• ekosystém MeSH
• fylogeneze * MeSH
• kyslík metabolismus   MeSH
• mitochondrie genetika   MeSH
• Oligohymenophorea klasifikace   MeSH
• protozoální DNA MeSH
• RNA ribozomální 18S genetika   MeSH
• rostliny parazitologie   MeSH
• sekvence nukleotidů MeSH
• stadia vývoje MeSH
• symbióza fyziologie   MeSH
• Tetrahymena thermophila klasifikace   genetika   MeSH
• Tetrahymena klasifikace   cytologie   izolace a purifikace   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Trap fluid of aquatic carnivorous plants of the genus Utricularia hosts specific microbiomes consisting of commensal pro- and eukaryotes of largely unknown ecology. We examined the characteristics and dynamics of bacteria and the three dominant eukaryotes, i.e. the algae-bearing ciliate Tetrahymena utriculariae (Ciliophora), a green flagellate Euglena agilis (Euglenophyta), and the alga Scenedesmus alternans (Chlorophyta), associated with the traps of Utricularia reflexa. Our study focused on ecological traits and life strategies of the highly abundant ciliate whose biomass by far exceeds that of other eukaryotes and bacteria independent of the trap age. The ciliate was the only bacterivore in the traps, driving rapid turnover of bacterial standing stock. However, given the large size of the ciliate and the cell-specific uptake rates of bacteria we estimated that bacterivory alone would likely be insufficient to support its apparent rapid growth in traps. We suggest that mixotrophy based on algal symbionts contributes significantly to the diet and survival strategy of the ciliate in the extreme (anaerobic, low pH) trap-fluid environment. We propose a revised concept of major microbial interactions in the trap fluid where ciliate bacterivory plays a central role in regeneration of nutrients bound in rapidly growing bacterial biomass.

• MeSH
• anaerobióza MeSH
• Bacteria MeSH
• biomasa MeSH
• Chlorophyta MeSH
• Ciliophora fyziologie   MeSH
• ekologie * MeSH
• koncentrace vodíkových iontů MeSH
• Magnoliopsida chemie   růst a vývoj   mikrobiologie   parazitologie   MeSH
• mikrobiální společenstva MeSH
• stadia vývoje MeSH
• symbióza fyziologie   MeSH
• Tetrahymena růst a vývoj   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH