Phylloplane yeasts from Portugal: Seven new anamorphic species in the Tremellales lineage of Hymenomycetes (Basidiomycota) producing orange colonies (2023)

Endophytic yeasts are yeasts that can colonize healthy plant tissue without causing any harm to the host plant. This work aimed to explore endophytic yeast diversity in leaf tissue of major agricultural crops (rice, maize, and sugarcane) in Thailand, using a culture-dependent approach. A total of 311 leaf samples, consisting of rice (n= 100), corn (n= 109) and sugarcane (n= 102). From tissue samples of rice (n= 92), maize (n= 76) and sugarcane (n= 78) leaves, 117, 118 and 123 region-based yeast strains were isolated and identified, respectively. Large subunit (LSU) D1/D2 rRNA gene sequence analysis for yeast species in both the phyla Basidiomycota and Ascomycota. Higher amounts of basidiomycete yeast than ascomycete yeast were detected in the leaf tissue of all three cultures. Pseudozyma (Dirkmeia) churashimaensis (Ustilaginales) was the most prevalent yeast species in rice and corn leaves with relative frequencies (RF) of 35.9 % and 17.8 %, respectively. While the predominant species in the sugarcane leaves was Meyerozyma caribbica (Saccharomycetales) with an RF of 14.6 %. In addition, six new yeast species and one new yeast genus were proposed. Our findings suggest that these plant species are good sources from which new yeast species can be isolated.

Epiphytic yeast diversity from sugarcane (Saccharum officinarum Linn.) phyllospheres in Thailand was investigated by a culture-independent method based on analysis of the D1/D2 domains of large subunit rRNA gene sequences. . Forty-five samples of sugarcane leaves from ten provinces of Thailand were randomly collected. A total of 1342 clones from 45 clone libraries were obtained. 426 clones (31.7%) were closely related to yeast strains in the GenBank database and clustered into 31 operational taxonomic units (OTUs) with a similarity threshold of 99%. All OTU sequences were classified in the phylum Basidiomycota, which were closely related to 11 yeast species in seven genera, including Cryptococcus flavus, Hannaella coprosmaensis, Rhodotorula taiwanensis, Jaminaea angkoreiensis, Malassezia restricta, Pseudozyma antarctica, Pseudozyma aphidis, Pseudozyma hubeiensis, Pseudozyma prolifica, Pseudozyma shanxiensis, and Sporobolomyces vermiculatus. The most predominant yeasts detected belonged to Ustilaginales with a relative frequency of 89.4% and the predominant yeast genus was Pseudozyma. However, most could not be identified as known yeast species and these sequences may represent the sequences of new yeast taxa. Furthermore, the OTU which is closely related to P. prolifica was commonly detected in the sugarcane phyllosphere.

The Tremellomycetes (Basidiomycota) contain a large number of unicellular and dimorphic fungi with stable free-living unicellular states in their life cycles. These fungi have been conventionally classified as basidiomycete yeasts based on their physiological and biochemical characteristics. Many currently recognized genera of these yeasts are defined primarily on the basis of phenotypic characters and are highly polyphyletic. Here we reconstruct the phylogeny of most described anamorphic and teleomorphic tremellomycete yeasts using Bayesian inference, maximum likelihood, and neighbor joining analysis based on the sequences of seven genes, including three rRNA genes, namely the small subunit of the Ribosomal DNA (rDNA), the D1/D2 domains of the large subunit of rDNA, and the internal transcribed spacer regions (ITS 1 and 2) of rDNA, including rDNA 5.8S; and four protein-encoding genes, namely the two RNA polymerase II subunits (RPB1 and RPB2), translation elongation factor 1-α (TEF1), and the mitochondrial cytochrome b (CYTB) gene. With consideration of morphological, physiological, and chemotaxonomic characters and the congruence of phylogenies inferred from analyzes using different algorithms based on different data sets consisting of the seven genes combined, the three rRNA genes, and the coding genes From individual proteins, five corresponding major lineages were resolved into the orders Cystofilobasidiales, Filobasidiales, Holtermanniales, Tremellales, and Trichosporonales. A total of 45 strongly supported monophyletic clades with multiple species and 23 single-species clades were recognized. This phylogenetic framework will be the basis for the proposal of an updated taxonomic system of tremellomycete yeasts that will be compatible with the current taxonomic system of filamentous basidiomycetes that conform to the "one fungus, one name" principle.

The families and genera assigned to Tremellomycetes have been circumscribed mainly by morphology and, for yeasts, also by biochemical and physiological characteristics. This phenotype-based classification is largely in conflict with molecular phylogenetic analyses. Here we propose a phylogenetic classification framework for the Tremellomycetes based on the results of phylogenetic analyzes of a seven-gene dataset covering most tremellomycete yeasts and closely related filamentous taxa. Constituencies of taxonomic units at recognized order, family, and genus levels were quantitatively assessed using phylogenetic range boundary optimization (PRBO) and modified General Yule Mixed Coalescing (GMYC) tests. In addition, a comprehensive phylogenetic analysis was performed on an expanded LSU rRNA gene sequence dataset (D1/D2 domains) encompassing as many teleomorphic and filamentous taxa as were available within Tremellomycetes to investigate relationships between yeast and filamentous taxa and to examine the stability of subsamples. clades. Based on the results inferred from the molecular data and the morphological and physicochemical characteristics, we propose an updated classification for the Tremellomycetes. We accept five orders, 17 families and 54 genera, including seven new families and 18 new genera. In addition, seven families and 17 genera are modified and a new species name and 185 new combinations are proposed. We propose to use the term pro tempore or pro tem. in abbreviation to indicate the names of the species that are temporarily maintained.

European Journal of Protistology, Volumen 50, Número 3, 2014, pp. 270-313

We describe 11 new species of Thaumatomonadida using light and electron microscopy and rDNA gene sequences (18S, ITS1, 5.8S, ITS2). We found clear distinctions between the major clades in molecular and morphological traits that now support the division of Thaumatomastix into three genera: new marine genera Ovaloplaca (oval plate scales) and Thaumatospina (triangular plate scales), both with a distinctive coil-based spine. radially symmetric. -scales, restricting Thaumatomastix to freshwater species with putatively non-homologous eccentric column scales and thicker triangular plate scales. The new genus Scutellomonas lacks spinal scales, has oval plate scales with a deeply depressed upper level as in Ovaloplaca, with which it forms a clade having a short/absent anterior cilium. Cowlomonas gene. north. maybe he's naked. We describe two new Allas species, two new Thaumatomonas, and one new Reckertia species, and transfer R. hindoni to Thaumatomonas. Triangular-scaled Reckertia has variegated plate scales and ciliary scales. Thaumatomonas rDNA trees reveal two clades: zhukovi/seravini (predominantly triangular scales); coloniensis/oxoniensis/lauterborni/constricta/solis (scales mostly oval). We hypothesize that the ancestor of Thaumatomonadidae had radially symmetric coil-based spine scales and triangular plate scales, coil-based spine scales were lost in a lineage, and eccentric spine scales evolved in Thaumatomastix. Coil-based spine scales arguably evolved from triangular plate scales and single-level ciliary scales (Ovaloplate and Reckertia only) from plate scale rudiments. We present a unified scheme for the evolution and development of scales in Imbricatea.

Protista, Volume 165, Number 5, 2014, pp. 605-635

The family Viridiraptoridae represents a morphologically and ecologically distinct lineage of flagellate glissomonads (Cercozoa, Rhizaria). It currently comprises two highly specialized algivorous genera that inhabit freshwater ecosystems, Orciraptor and Viridiraptor, for which ultrastructural data were lacking. In this study, the ultrastructure of Viridiraptor invadesHess y Melkonian, the only described species of the viridiraptorid type genus, has been studied by transmission and scanning electron microscopy. In particular, the flagellar transition region and basal apparatus, both reconstructed from serial sections, revealed ultrastructural features consistent with the phylogenetic placement of viridiraptorids within Glissomonadida: the transition region contains a distal plate/collar complex and the basal apparatus comprises two roots and an anterior root, all known from other glissomonads. However, two additional small microtubular roots, two conspicuous rhizoplasts, and probasal bodies present during interphase represent novel features. In addition, an acorn/V-shaped system of filaments was discovered at the proximal end of the flagellar transition region and used to establish a basal body triplet numbering system for Rhizaria flagellate cells. Finally, ultrastructural data on perforated algal cell walls suggest that the Viridiraptor reticulocyst described above represents a mesh-like covering derived from an extrusome that supports the invasion/feeding process.

Bioorganic and Medicinal Chemistry Letters, Volume 24, Number 7, 2014, pp. 1707-1710

Trypanosoma brucei and Trypanosoma cruzi are the etiological agents of sleeping sickness and Chagas disease, respectively, two of the 17 preventable tropical infectious diseases (NTDs) that have been neglected by governments and organizations working in the health sector, as well as as by the pharmaceutical industries. The high toxicity and resistance are problems of the conventional drugs used against trypanosomiasis, hence the need to develop new drugs with trypanocidal activity. In this work we have evaluated the trypanocidal activity of a series of N1,N2-dibenzylethane-1,2-diamine hydrochlorides (benzyldiamines) and N1-benzyl,N2-methylferrocenylethane-1,2-diamine hydrochlorides (ferrocenyldiamines) against T parasite strains T. brucei and T. cruzi. We show that the incorporation of the ferrocenyl group in benzyldiamines increases trypanocidal activity. The molecules exhibit potential in vitro trypanocidal activity against all parasite strains. A cytotoxicity assay was also carried out to assess toxicity in HepG2 cells.

European Journal of Protistology, Volumen 56, 2016, pp. 41-50

A new Diplophrys-like organism, Fibrophrys columna, was isolated from the Hiuchigaike pond in Japan. F. columna showed a nearly orbicular or broadly elliptical cell shape and has fine filamentous branching ectoplasmic elements emanating from both polar ends of the cell. Cells also contain orange, amber, or colorless lipid bodies. Although its entire cell morphology resembles that of the genus Diplophrys, Fibrophrys is clearly differentiated from Diplophrys on the basis of 18S rDNA sequences. Molecular phylogenetic analysis showed a close relationship of F. columna to Amphifila marina, and its sequence is similar to many environmental stramenopile sequences. F. columna cells measured 5.0–8.3 × 5.6–10.3 μm and sometimes possessed hernia-like teeth instead of filamentous ectoplasmic elements. A shaft-like electron-dense body was observed in the mitochondria. We also studied the ultrastructure of another Fibrophrys strain, Fibrophrys sp. E-1, which is different from the type strain of F. columna. A ladder-shaped pattern was recognized on the outer part of the unidentified cytoplasmic membranes connected with the mitochondria. Unidentified cytoplasmic membranes were connected to the outer nuclear, lipid body, and mitochondrial membranes. We propose a new genus, Fibrophrys, and a new species, F. columna, based on these ultrastructural and molecular features.

Protista, Volume 166, Number 5, 2015, pp. 585-597

The phylum Haptophyta (Diaphoratickes) contains marine algae that perform biomineralization, extruding large, distinctive calcium carbonate scales (coccoliths) that completely cover the cell. Coccolith production is an important part of the global carbon cycle; however, the membrane trafficking pathway by which they are secreted remains to be elucidated. In most eukaryotes, downstream Golgi membrane trafficking involves five heterotetrameric adapter protein (AP) complexes, which impart cargo selection specificity. To better understand coccolith secretion, we performed comparative genomic, phylogenetic, and transcriptomic analyzes of AP complexes in Emiliania huxleyi strains 92A, Van556, EH2, and CCMP1516, and the related haptophytes Gephyrocapsa oceanica and Isochrysis galbana; the latter has lost the ability to biomineralize. We show that haptophytes have a modified membrane trafficking system (MTS), as we found losses and duplications of AP subunits. Furthermore, we identified a single conserved subunit of the AP-related TSET complex, the expression of which suggests a functional role in membrane trafficking. Finally, we detected novel ear adaptin alpha and ear adaptin gamma proteins, the first of their kind described outside of opisthokonts. These new MTS ear and sculpting proteins may support the biomineralization capacity in haptophytes, enhancing their ability to perform this highly specialized form of secretion.

Harmful Algae, Volume 36, 2014, pp. 11-21

The feeding ecology of the newly described heterotrophic dinoflagellate Stoeckeria changwonensis was explored. The feeding behavior of S. changwonensis and the types of prey species it feeds on were investigated with several different types of microscopes and high-resolution video microscopy. In addition, growth and ingestion rates of S. changwonensis were measured as a function of prey concentration for the blood cells of the perch (Lateolabrax japonicus), the raphidophyte Heterosigma akashiwo, the cryptophytes Rhodomonas salina and Teleaulax sp., and the dinoflagellate. phototrophic Amphidinium carterae. S. changwonensis feeds on prey via a stalk, after anchoring the prey using a bast filament. This type of feeding behavior is similar to that of Stoeckeria algicida, Pfiesteria piscicida and Luciella masanensis in the family Pfiesteriaceae; however, S. changwonensis feeds on several different types of prey than the other heterotrophic dinoflagellates. S. changwonensis ingested globules of perch and various species of algae, in particular the large teak dinoflagellate Lingulodinium polyedrum, which is not consumed by the other stem feeders. H. akashiwo and perch globules supported the positive growth of S. changwonensis, but R. salina, Teleaulax sp. and A. carterae, which support the positive growth of P. piscicida and L. masanensis, did not support the positive growth of S. changwonensis. . With increasing mean prey concentration, the growth rates of S. changwonensis in H. akashiwo and perch blood cells increased rapidly and then slowly or became saturated. The maximum growth rates of S. changwonensis in H. akashiwo and perch blood cells were 0.376 and 0.354d⁻¹, respectively. In addition, the maximum ingestion rates of S. changwonensis in H. akashiwo and perch blood cells were 0.35 ngCpredator⁻¹d⁻¹(3.5cellspredator⁻¹d⁻¹) and 0.27 ngCpredator⁻¹d⁻¹(29predator cells⁻¹d⁻¹), respectively. These maximum growth and ingestion rates of S. changwonensis in H. akashiwo, the blood cells of perch, R. salina, Teleaulax sp. and A. carterae differed considerably from those of S. algicida, P. piscicida and L. masanensis in the same prey species. Therefore, the feeding behavior of S. changwonensis may differ from that of other species in the family Pfiesteriaceae.