Saccharomycomorphapsychra n. g., n. sp., a Novel Member of Glissmonadida (Cercozoa) Isolated from Arctic and Antarctica

Abstract

A novel genus and species within the order Glissmonadida (Cercozoa, Rhizaria), Saccharomycomorpha psychra n. g., n. sp., is described from lichen in the Ny-Alesund region (High Arctic) and moss in the Fildes peninsula of King George Island (Maritime Antarctica). Cells were spherical and did not appear to present flagella in organic-rich Potato Dextrose Agar medium where they were able to feed osmotrophically. Molecular phylogenetic analyses based on 18S rRNA gene sequence demonstrated that Saccharomycomorpha psychra belong to "clade T" within the order Glissmonadida (Cercozoa, Rhizaria). All three investigated strains could grow at 4°C and had an optimum growth temperature of 12°C, 20°C, and 20°C, while a maximum growth temperature of 20°C, 20°C, and 25°C, respectively. In conclusion, we established the phenotypic identity of "clade T," which until now was exclusively detected by environmental sequences, and erect a new family Saccharomycomorphidae for "clade T." Nomenclatural, morphological and ecological aspects of this novel species are discussed.CERCOZOA is a large assemblage of unicellular eukaryotic microorganisms with highly variable morphological features, mainly identified by molecular phylogenetic methods (Cavalier-Smith 1998). Cercozoan species have adapted to different niches and have been isolated from various habitats, for example freshwater (Dumack et al. 2017b), marine biotopes (Shiratori and Ishida 2016), soils, plant roots, and leaves (Dumack et al. 2017a).The order Glissomonadida is established to solve the confusion pertaining to the family Heteromitidae (Cercozoa), which was not appropriate due to the misuse of "Heteromita globosa" in the gliding biflagellates. Species in Glissomonadida are predominantly biflagellate gliding bacterivores found largely in soil and freshwater (Howe et al. 2009(Howe et al. , 2011. Glissomonadida initially incorporates four families (Sandonidae, Bodomorphidae, Proleptomonadidae, Allapsidae) and eight genera (Sandona, Flectomonas, Neoheteromita, Bodomorpha, Proleptomonas, Allapsa, Allantion, Teretomonas). It further comprises seven distinct lineages that were identified by environmental sequences only and provisionally labeled as clades T, U, W, X, Y, Z, and "Group Te" (Howe et al. 2009). These clades are essential for the reconstruction of character evolution within Glissomonadida. Although the mysteries of Clade W [= Dujardina sp./= Dujardinidae] and Clade X [=Orciraptor sp. and Viridiraptor sp./= Viridiraptoridae] were uncovered and the genus Mollimonas (Mollimonadinae, Sandonidae) was established in previous studies (Hess and Melkonian 2013;Howe et al. 2011), the morphological entities for the remaining five clades (clades T, U, Y, Z, and Group Te) remained unexplored.

Soil filtration‐sedimentation improves shelled protist recovery in eukaryotic eDNA surveys

“…Among Sarcomonadea, only one (Glissomonadida_X) out of 28 genera was depleted in filtered samples. The most abundant ASV in this genus has an exact match (Megablast, E ‐value = 0) with a newly described species, Saccharomycomorpha psychra (accession MH791032), likely parasitising mosses and lichens (Feng et al, 2021), so that thalli retention by the filter may also explain their reduction.…”

Mrakia polaris sp. nov. and Mrakia amundsenii sp. nov. (Mrakiaceae, Cystofilobasidiales), two novel psychrophilic yeast species isolated from Arctic habitats

“…Cultures were incubated in YM broth (Difco) at 15°C for 7 days for scanning electron microscopy (SEM) analysis. For SEM, yeast cells were processed following the protocol outlined by Feng et al [20] and were examined using a cold field-emission scanning electron microscope (Hitachi SU8010).…”

“…For SEM, yeast cells were processed following the protocol outlined by Feng et al . [20] and were examined using a cold field-emission scanning electron microscope (Hitachi SU8010).…”

Freeze Substitution Accelerated via Agitation: New Prospects for Ultrastructural Studies of Lichen Symbionts and Their Extracellular Matrix

“…Highpressure freezing (HPF) and FS for 68 h were also applied to the protists Saccharomycomorpha psychra n. g., n. sp., isolated from the Arctic lichens Cladonia pocillum [32].…”