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Basidiomycetous yeasts remain an almost unexplored source of enzymes with great potential in several industries. Tausonia pullulans (Tremellomycetes) is a psychrotolerant yeast with several extracellular enzymatic activities reported, although the responsible genes are not known. We performed the genomic sequencing, assembly and annotation of T. pullulans strain CRUB 1754 (Perito Moreno glacier, Argentina), a gene survey of carbohydrate-active enzymes (CAZymes), and analyzed its secretome by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) after growth in glucose (GLU) or starch (STA) as main carbon sources. T. pullulans has 7210 predicted genes, 3.6% being CAZymes. When compared to other Tremellomycetes, it contains a high number of CAZy domains, and in particular higher quantities of glucoamylases (GH15), pectinolytic enzymes (GH28) and lignocellulose decay enzymes (GH7). When the secretome of T. pullulans was analyzed experimentally after growth in starch or glucose, 98 proteins were identified. The 60% of total spectral counts belonged to GHs, oxidoreductases and to other CAZymes. A 65 kDa glucoamylase of family GH15 (TpGA1) showed the highest fold change (tenfold increase in starch). This enzyme contains a conserved active site and showed extensive N-glycosylation. This study increases the knowledge on the extracellular hydrolytic enzymes of basidiomycetous yeasts and, in particular, establishes T. pullulans as a potential source of carbohydrate-active enzymes. Key points: • Tausonia pullulans genome harbors a high number of genes coding for CAZymes. • Among CAZy domains/families, the glycoside hydrolases are the most abundant. • Secretome analysis in glucose or starch as main C sources identified 98 proteins. • A 65 kDa GH15 glucoamylase showed the highest fold increase upon culture in starch. [ABSTRACT FROM AUTHOR]

We studied degradation patterns and microorganisms preserved in permineralized stems of Rhexoxylon piatnitzky, Protojuniperoxylon ischigualastense, and Agathoxylon argentinum from the Valle de la Luna Member of the Ischigualasto Formation (Upper Triassic, San Juan, Argentina). All three species show loss of middle lamella, thinning, and whitening of tracheid cell walls, and detachment of the S3 layer, consistent with selective delignification by white rot. This type of rot is the product of lignin and cellulosic degradation by Basidiomycetes and Ascomycetes. Rhexoxylon piatnitzkyi also shows small cavities, more or less circular in outline, on the wall of tracheids. This is known as soft rot and can be produced by some Ascomycetes, the anamorphic phases of diverse fungi, and tunneling bacteria. Additionally, abundant and diverse microorganisms were found. Rhexoxylon piatnitzkyi shows fragments of septate hyphae, evidence of bacterial activity, and structures of unknown affinity. Protojuniperoxylon ischigualastense presents structures common to anamorphic phases of diverse fungi, such as chlamydospores and conidiophores. Lastly, Agathoxylon argentinum bears coiled and septate hyphae, and a fan-shaped mycelium, whose significance is discussed. The microbiological study was complemented by the assessment of sedimentary and taphonomic data of the fossil-bearing beds. A gradual increment in humidity for the Valle de la Luna Member is interpreted, which concludes with a humidity peak in its upper section. This contribution represents the first detailed study of xylophagous and saprophyte micro-communities for the Ischigualasto Formation. The abundance and diversity of microorganisms described illustrate the complexity of wood-inhabiting micro-communities from the Carnian-Norian interval of Argentina. • Triassic woods from Ischigualasto Formation with soft, white, and white-pocket rot. • Fossil fungi and fungi-like microorganisms are described in stem tissues. • Dark globules are interpreted as evidence of bacterial activity. • Microorganisms correspond to abundant and diverse saprophytes and parasites. • A seasonal humid to subhumid climate with periodic droughts is inferred. [ABSTRACT FROM AUTHOR]

Ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.), an ectomycorrhiza (EM) dependent species, has been widely introduced in Patagonia, Argentina. This study used morphotyping, restriction analysis, and sequencing of EM root tips from ponderosa pine seedlings in two nurseries to assess the complete EM fungus (EMF) richness, to confirm doubtful identities of commonly reported morphotypes, and to evaluate the efficiency of morphotyping compared with molecular analysis. This interdisciplinary approach together with the fact that is the first study in which Patagonian nurseries EMF are genetically evaluated contributes to the general knowledge of this important group of fungi. Sequencing revealed the presence of 11 taxa. Basidiomycetes included Thelephoraceae (Tomentella sp.), Atheliaceae (Amphinema byssoides (Pers.) J. Erikss.), Hydnangiaceae (Laccaria sp.), Rhizopogonaceae (Rhizopogon roseolus (Corda) Th. Fr.), and Cortinariaceae (Hebeloma mesophaeum (Pers.) Quel.). Ascomycetes included Pezizaceae (Wilcoxina mikolae (Chin S. Yang & H.E. Wilcox) Chin S. Yang & Korf and Wilcoxina sp.) and Tuberaceae (Tuber sp.). Morphotyping proved to be useful for certain EMF species (R. roseolus, H. mesophaeum, A. byssoides, and to a lesser extent Tuber sp.) in which some morphological features are conspicuous and unique. Our detection of W. mikolae and Wilcoxina sp. are new records for ponderosa pine in Patagonia. All of the EM taxa identified are common to pine plantations and nurseries around the world, and no indigenous EM associated with native Nothofagus spp. were found. [ABSTRACT FROM AUTHOR]

Abstract: Evidence of fungal activity expressed as typical decay patterns is described from silicified podocarpaceous wood from the Eocene of Patagonia, Argentina. Decay features consist of tracheids of the secondary xylem that are degraded, resulting in thin-celled, lignin-free, translucent, circular to elliptical areas, some of which have cells devoid of all cell wall components including lignin, hemicellulose, and cellulose, and other areas that show only partial simultaneous decay of all cell wall layers. These patterns conform to the white rot and its variant white pocket rot decay patterns produced by basidiomycetes and ascomycetes in gymnosperm and angiosperm wood in modern terrestrial ecosystems. Coagulated opaque bodies in the lumen of some cells and enlarged secondary walls may represent host reactions to infection or remains of metabolic products of fungal enzymatic activity. Similar decay patterns and reaction features have been described from fossil woods ranging in age from the Devonian to the present. This record expands the fossil record of wood rot fungi and underscores their importance as drivers of biological cycles in ancient terrestrial ecosystems. [Copyright &y& Elsevier]

A new species, Geastrum episcopale, is described from Argentina. Detailed descriptions and illustrations of fresh and dry basidiomata are provided along with photographs of microscopic elements, such as spores, capillitium, calcium oxalate crystals, and exo- and endoperidium surfaces. This fungus is typical of the genus in its morphology and ecology but clearly differs from every known species. This species can be distinguished easily by the red-violet (to magenta) exoperidium and the lilac endoperidium. Specimens were collected on wet soil composed of a superficial layer of ca. 5 cm leaf litter and 15 cm of particulate and melanized lignocellulosic material (pH 6.5) under Eugenia uruguayensis and Nectandra sp. [ABSTRACT FROM AUTHOR]

Epicoccum purpurascens, a component of the bark micromycota, was evaluated as a potential biocontrol agent for three decay-causing hymenomycetes frequently found in Buenos Aires city trees, Ganoderma platense, Inonotus rickii and Rigidoporus ulmarius. Treatments consisted of dual cultures of E. purpurascens and xylophagous fungi on box elder ( Acer negundo) wood blocks. Two inoculation sequences were tested: (i) the biocontrol agent as the first microorganism inoculated followed by the pathogen; and (ii) the xylophagous fungus as the first microorganism inoculated followed by the biocontrol agent. After 3 months of incubation, percentage dry weight loss was calculated. When E. purpurascens was allowed to colonize wood blocks before the introduction of the xylophagous fungus, dry weight loss was significantly reduced in all instances. However, as a secondary colonizer, E. purpurascens mildly reduced the weight loss caused by G. platense, had no effect on degradation by I. rickii and increased wood weight loss by R. ulmarius. [ABSTRACT FROM AUTHOR]

As part of a project aimed at the selection of cold-adapted yeasts expressing biotechnologically interesting features, the extracellular enzymatic activity (EEA) of basidiomycetous yeasts isolated from glacial and subglacial waters of northwest Patagonia (Argentina) was investigated. Ninety-one basidiomycetous yeasts (belonging to the genera Cryptococcus, Leucosporidiella, Dioszegia, Mrakia, Rhodotorula, Rhodosporidium, Sporobolomyces, Sporidiobolus, Cystofilobasidium, and Udeniomyces) were screened for extracellular amylolytic, proteolytic, lipolytic, esterasic, pectinolytic, chitinolytic, and cellulolytic activities. Over 15% of the strains exhibited three or more different EEAs at 4 °C and more than 63% had at least two EEAs at the same temperature. No chitinolytic or cellulolytic activities were detected at 4 and 20 °C. Cell-free supernatants exhibited significantly higher (P < 0.01) protease and lipase activities at ≤10 °C, or even at 4 °C. In light of these findings, cold environments of Patagonia (Argentina) may be considered a potential source of cold-adapted yeasts producing industrially relevant cold-active enzymes. [ABSTRACT FROM AUTHOR]

A new basidiomycete genus, Rhizochaete (Phanerochaetaceae, Polyporales), is described. Rhizochaete is characterized by a smooth to tuberculate, pellicular hymenophore and hyphal cords that turn red or violet in potassium hydroxide, monomitic hyphal system of simple or nodose septate hyphae, cystidia, and small, cylindrical to subglobose basidiospores. It morphologically is most similar to Phanerochaete. Analyses of nuclear ribosomal and internal-transcribed spacer region sequence data support a close relationship between Rhizochaete and Phanerochaete. The new taxon R. brunnea, from southern Argentina, is described and illustrated. In addition, the new combinations R. americana, R. borneensis, R. filamentosa, R. fouquieriae and R. radicata are proposed. A key to the species of Rhizochaete is provided. [ABSTRACT FROM AUTHOR]

Conspicuous galls and witches' brooms frequently are symptoms of rust infections on plant hosts in the ecologically diverse northwestern region of Argentina. These symptoms are caused by systemic or locally systemic spermogonial-aecial infections, although uredinial and telial infections also might be involved. Sixteen species of rust fungi are treated in this paper, most of which cause a plant response that results in enlarged growth. Ypsilospora tucumanensis J.R. Hern.& J.F. Hennen on Inga edulis is described as a species new to science. Puccinia cordiae Arthur is cited as a new record for Argentina. These rusts also are included: Chaconia ingae, Gerwasia imperialis, Kuehneola loeseneriana, Prospodium appendiculatum, Prospodium elegans, Prospodium perornatum, Puccinia bougainvilleae, Puccinia pampeana, Ravenelia argentinica, Ravenelia hieronymi, Ravenelia papillosa, Ravenelia spegazziniana, Uromyces cestri and Uropyxis rickiana. For some of the scientific names, lectotype specimens have been designated. [ABSTRACT FROM AUTHOR]

Presents information on several species of Clavariaceae from Argentina. Clavaria minima; Clavaria vermicularis; Clavicorona turgida; Clavulinopsis corniculata.