Morphology and Ecology of Two New Amoebae, Isolated From a Thalassohaline Lake, Dziani Dzaha

Aucher, Willy; Delafont, Vincent; Ponlaitiac, Elodie; Alafaci, Aurélien; Agogué, Hélène; Leboulanger, Christophe; Bouvy, Marc; Héchard, Yann

doi:10.1016/j.protis.2020.125770

Cited by 6 publications

(20 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Dziani Dzaha ecosystem hosts an atypical biological assemblage, almost exclusively composed of microorganisms, with biomass dominated by two phytoplanktonic species (the picoeukaryote, Picocystis salinarum, and the large filamentous cyanobacterium, Arthrospira fusiformis; [Bernard et al, 2019, Cellamare et al, 2018. A diverse heterotrophic prokaryotic community of Archaea and Bacteria complement the microbial community, accompanied with scarce eukaryotic protists [Aucher et al, 2020, Hugoni et al, 2018; no aquatic metazoans have been detected to date [Hugoni et al, 2018]. By contrast with other tropical saline-alkaline ecosystems where Arthrospira profusely develops seasonally (for example in Rift Valley lakes, Krienitz and Schagerl, 2016), no grazing control of planktonic biomass by macroorganisms or drastic seasonal successions in plankton community's composition was identified.…”

Section: Introductionmentioning

confidence: 99%

Geochemistry of an endorheic thalassohaline ecosystem: the Dziani Dzaha crater lake (Mayotte Archipelago, Indian Ocean)

Sarazin¹,

Jézéquel²,

Leboulanger³

et al. 2021

Comptes Rendus. Géoscience

Self Cite

View full text Add to dashboard Cite

Dziani Dzaha is a maar the age of which is close to 4000 years. While its water is thought to have originated from seawater it is now considered as an extreme environment due to its hypersaline and alkaline characteristics. Those extreme features have led to the simplification of the trophic network. Cyanobacteria account for up to 95% of the photosynthetic biomass. The main biogeochemical processes, i.e. photosynthesis, bacterial sulfate reduction and methanogenesis could explain the current water composition. As far as we know, this ecosystem could be unique on Earth, extending the nature and chemical limits of aquatic inland ecosystems.

show abstract

Section: Introductionmentioning

confidence: 99%

Geochemistry of an endorheic thalassohaline ecosystem: the Dziani Dzaha crater lake (Mayotte Archipelago, Indian Ocean)

Sarazin¹,

Jézéquel²,

Leboulanger³

et al. 2021

Comptes Rendus. Géoscience

Self Cite

View full text Add to dashboard Cite

show abstract

“…Additionally, some obligate predators of other eukaryotes are known to exist (e.g., Colpodella and Palustrimonas), even though they have not been isolated under stable predator-prey culture [12,13]. Heterotrophic isolates from hypersaline environments were assigned to Heterolobosea in Discoba (Euplaesiobystra, Pharyngomonas, Pleurostomum, Tulamoeba, Selenaion, Percolomonas, and Aurem), Ciliophora in Alveolata (Trimyema, Fabrea, Schmidingerothrix, and Platynematum), Stramenopila (Aladia, Halocafeteria, and Haloplacidia), Colpodella in Alveolata, and Palustrimonas in Alveolata [1,[14][15][16][17]. Many of these genera are restricted to hypersaline environments, proved to be mostly novel species in these systems.…”

Section: Introductionmentioning

confidence: 99%

The Diversity Patterns of Rare to Abundant Microbial Eukaryotes Across a Broad Range of Salinities in a Solar Saltern

et al. 2021

View full text Add to dashboard Cite

Solar salterns are excellent artificial systems for examining species diversity and succession along salinity gradients. Here, the eukaryotic community in surface water of a Korean solar saltern (30 to 380 practical salinity units) was investigated from April 2019 to October 2020 using Illumina sequencing targeting the V4 and V9 regions of 18S rDNA. A total of 926 operational taxonomic units (OTUs) and 1,999 OTUs were obtained with the V4 and V9 regions, respectively. Notably, most of the OTUs were microbial eukaryotes, and the high-abundance groups (> 5% relative abundance (RA), Alveolata, Stramenopila, Archaeplastida, and Opisthokonta) usually accounted for > 90% of the total cumulative read counts and > 80% of all OTUs. Moreover, the high-abundance Alveolata (larger forms) and Stramenopila (smaller forms) groups displayed a significant inverse relationship, probably due to predator–prey interactions. Most of the low-abundance (0.1–5% RA) and rare (< 0.1% RA) groups remained small portion during the field surveys. Taxonomic novelty (at < 90% sequence identity) was high in the Amoebozoa, Cryptista, Haptista, Rhizaria, and Stramenopila groups (69.8% of all novel OTUs), suggesting the presence of a large number of hidden species in hypersaline environments. Remarkably, the high-abundance groups had little overlap with the other groups, implying the weakness of rare-to-prevalent community dynamics. The low-abundance Discoba group alone temporarily became the high-abundance group, suggesting that it is an opportunistic group. Overall, the composition and diversity of the eukaryotic community in hypersaline environments may be persistently stabilized, despite diverse disturbance events.

show abstract

“…A related 18S rDNA sequence has also been obtained from Hutt Lagoon, Australia (Park and Simpson, 2015). The more recently described Euplaesiobystra dzianiensis is a halotolerant species isolated from 52 PSU saline water in Dziani Dzaha, a small crater lake on a Caribbean Island (Aucher et al, 2020). Thus, the genus Euplaesiobystra is present in hypersaline waters worldwide.…”

Section: Introductionmentioning

confidence: 99%

“…Heterolobosea is regarded as a crucial group to better understand adaptation in halophilic/ halotolerant eukaryotes because it includes several contrasting clades of these organisms (Kirby et al, 2015;Harding and Simpson, 2018;Jhin and Park, 2019). Recently, several studies have demonstrated that many halophilic/halotolerant eukaryotes (e.g., Aurem, Euplaesiobystra, Percolomonas, Pharyngomonas, Pleurostomum, Selenaion, and Tulameoba) are novel genera belonging to Heterolobosea (Park et al, 2007(Park et al, , 2009(Park et al, , 2012Park and Simpson, 2011;Jhin and Park, 2019;Tikhonenkov et al, 2019;Aucher et al, 2020;Carduck et al, 2021). In addition to expanding the known diversity of halophilic eukaryotes, these studies suggest that a more complex food web than previously thought may function in hypersaline environments (Lee et al, 2022a).…”

Section: Introductionmentioning

confidence: 99%

“…At least four clades in Heterolobosea are largely or exclusively halophilic, with Euplaesiobystra representing one of these clades (Park et al, 2009;Harding and Simpson, 2018;Jhin and Park, 2019;Aucher et al, 2020). Like many heteroloboseids, Euplaesiobystra hypersalinica is an amoeboflagellate that can change from an amoeboid form to a flagellate one (or vice versa) during its life cycle (Pánek et al, 2017;Harding and Simpson, 2018), whereas the second species, Euplaesiobystra dzianiensis, has not been observed in a flagellate form (Aucher et al, 2020). Park et al (2009) formally described Euplaesiobystra hypersalinica based on an isolate from 293 PSU saline water in a Korean solar saltern, with the same species having been isolated by different researchers from ~140 PSU saline water in Portugal (T.A.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Accumulation patterns of intracellular salts in a new halophilic amoeboflagellate, Euplaesiobystra salpumilio sp. nov., (Heterolobosea; Discoba) under hypersaline conditions

2022

View full text Add to dashboard Cite

Halophilic microbial eukaryotes are present in many eukaryotic lineages and major groups; however, our knowledge of their diversity is still limited. Furthermore, almost nothing is known about the intracellular accumulation of salts in most halophilic eukaryotes. Here, we isolate a novel halophilic microbial eukaryote from hypersaline water of 134 practical salinity units (PSU) in a solar saltern. This species is an amoeboflagellate (capable of the amoeba-flagellate-cyst transformation) in the heterolobosean group and belongs to the genus Euplaesiobystra based on morphological data and 18S rDNA sequences. However, the isolate is distinct from any of the described Euplaesiobystra species. Especially, it is the smallest Euplaesiobystra to date, has a distinct cytostome, and grows optimally at 75–100 PSU. Furthermore, the phylogenetic tree of the 18S rDNA sequences demonstrates that the isolate forms a strongly supported group, sister to Euplaesiobystra hypersalinica. Thus, we propose that the isolate, Euplaesiobystra salpumilio, is a novel species. E. salpumilio displays a significantly increased influx of the intracellular Na+ and K+ at 50, 100, and 150 PSU, compared to freshwater species. However, the intracellular retention of the Na+ and K+ at 150 PSU does not significantly differ from 100 PSU, suggesting that E. salpumilio can extrude the Na+ and K+ from cells under high-salinity conditions. Interestingly, actively growing E. salpumilio at 100 and 150 PSU may require more intracellular accumulation of Na+ than the no-growth but-viable state at 50 PSU. It seems that our isolate displays two salt metabolisms depending on the tested salinities. E. salpumilio shows a salt-in strategy for Na+ at lower salinity of 100 PSU, while it displays a salt-out strategy for Na+ at higher salinity of 150 PSU. Our results suggest that the novel halophilic E. salpumilio fundamentally uses a salt-out strategy at higher salinities, and the accumulation patterns of intracellular salts in this species are different from those in other halophilic microbial eukaryotes.

show abstract

Morphology and Ecology of Two New Amoebae, Isolated From a Thalassohaline Lake, Dziani Dzaha

Cited by 6 publications

References 30 publications

Geochemistry of an endorheic thalassohaline ecosystem: the Dziani Dzaha crater lake (Mayotte Archipelago, Indian Ocean)

Geochemistry of an endorheic thalassohaline ecosystem: the Dziani Dzaha crater lake (Mayotte Archipelago, Indian Ocean)

The Diversity Patterns of Rare to Abundant Microbial Eukaryotes Across a Broad Range of Salinities in a Solar Saltern

Accumulation patterns of intracellular salts in a new halophilic amoeboflagellate, Euplaesiobystra salpumilio sp. nov., (Heterolobosea; Discoba) under hypersaline conditions

Contact Info

Product

Resources

About