Enhancing biodegradation of vegetable oil-contaminated soil with soybean texturized waste, spent mushroom substrate, and stabilized poultry litter in microcosm systems.

Industrial activities contribute to environmental pollution, particularly through unregulated effluent discharges, causing adverse effects on ecosystems. Vegetable oils, as insoluble substances, exacerbate this pollution, forming impermeable films and affecting the oxygen transfer, leading to serious habitat disruption. Organic wastes, such as soybean texturized waste, spent mushroom substrate, and stabilized poultry litter, were assessed for their efficacy in enhancing the degradation of vegetable oil in contaminated soil. For this purpose, contaminated soil was amended with each of the wastes (10% w/w) using microcosm systems, which were monitored physico-chemically, microbiologically and toxicologically. Results indicate that the wastes promoted significant oil degradation, achieving 83.1, 90.7, and 86.2% removal for soybean texturized waste, spent mushroom substrate, and stabilized poultry litter, respectively, within a 90-day period. Additionally, they positively influenced soil microbial activity, as evidenced by increased levels of culturable microorganisms and hydrolytic microbial activity. While bioassays indicated no phytotoxicity in most cases, soybean texturized waste exhibited inhibitory effects on seed germination and root elongation of Lactuca sativa. This study significantly enhances our comprehension of remediation techniques for sites tainted with vegetable oils, highlighting the critical role of organic waste as eco-friendly agents in soil restoration. Emphasizing the practical implications of these findings is imperative to underscore the relevance and urgency of addressing vegetable oil contamination in soil. Moving forward, tailored strategies considering both contaminant characteristics and soil ecosystem traits are vital for ensuring effective and sustainable soil remediation.

Assessment of agronomic crops-based residues for growth and nutritional profile of Pleurotus eryngii / Avaliação de resíduos de cultivos agronômicos para crescimento e perfil nutricional de Pleurotus eryngii

Among edible mushrooms, Pleurotus eryngii is unique due to its flavor, admirable medicinal and nutritional profiling. Pakistan is an agricultural country diverse in various crops. However, the residues of the horticultural and agronomic crops are wasted without utilization in the food chain. Hence, a study was performed to assess the performance of relatively low-cost, easily available crops residues i.e. cotton, rice, wheat, mustard and water chestnut for yield and nutrition enhancement of Pleurotus eryngii strains P9 (China) and P10 (PSU-USA). The results revealed that morphological attributes i.e. mycelium run, fruit development, yield and biological efficiency were significantly higher by using cotton waste as compared to other substrates. Regarding biochemical attributes i.e. total soluble solids (12.67 °Brix), phenolics (259.6 mg/100g), moisture (92.3%) and ascorbic acid contents (2.9 mg/100ml) were also significantly higher by using cotton waste. Whereas, acidity (0.30%), reducing sugar (7.67%), non-reducing (4.33%) and total sugars contents (12%) were found highest by using mustard straw. Nutrient analysis of substrates showed that nutrient levels were increased after harvesting of crop as compared to before harvesting levels. Overall results revealed that cotton waste and mustard straw are promising substrates for Pleurotus eryngii better growth and have potential in yield and nutrition enhancement. Moreover, P10 strain performed better as compared to P9.

Entre os cogumelos comestíveis, Pleurotus eryngii é único por causa de seu sabor e seu admirável perfil medicinal e nutricional. O Paquistão é um país agrícola com diversas culturas. No entanto, os resíduos das culturas hortícolas e agronômicas são desperdiçados sem aproveitamento na cadeia alimentar. Assim, um estudo foi realizado para avaliar o desempenho de resíduos de culturas com custos relativamente baixos e facilmente disponíveis, ou seja, algodão, arroz, trigo, mostarda e castanha-de-água, para o aumento da produtividade e nutrição de cepas de P. eryngii P9 (China) e P10 (PSU-EUA). Os resultados revelaram que os atributos morfológicos, ou seja, função do micélio, desenvolvimento de frutos, rendimento e eficiência biológica, foram significativamente maiores usando resíduos de algodão em comparação com outros substratos. Em relação aos atributos bioquímicos, ou seja, sólidos solúveis totais (12,67 °Brix), fenólicos (259,6 mg / 100 g), umidade (92,3%) e teores de ácido ascórbico (2,9 mg / 100 ml), também foram significativamente maiores usando resíduos de algodão. Já os teores de acidez (0,30%), açúcares redutores (7,67%), não redutores (4,33%) e açúcares totais (12%) foram os mais elevados na palha de mostarda. A análise de nutrientes dos substratos mostrou que os níveis de nutrientes aumentaram após a colheita da cultura em comparação com os níveis antes da colheita. Os resultados gerais revelaram que os resíduos de algodão e a palha de mostarda são substratos promissores para o melhor crescimento de P. eryngii e têm potencial na melhoria da produtividade e nutrição. Além disso, a cepa P10 apresentou melhor desempenho em comparação com a P9.

Second world record for two Calvatia species (Agaricaceae: Basidiomycota) / Segundo registro mundial para duas espécies de Calvatia (Agaricaceae: Basidiomycota)

Calvatia is a genus of gasteroid fungi, comprising about 47 species worldwide. In this paper we report the second worldwide occurrence of two poorly known species of Calvatia, recorded in the Cerrado biome of Brazil: C. oblongispora and C. nodulata. Detailed morphological descriptions and illustrations, including scanning electron micrographs of hyphae and basidiospores are provided, as well a discussion on their taxonomy and geographic distribution.(AU)

Calvatia é um gênero de fungos gasteroides que compreende cerca de 47 espécies em todo o mundo. Neste artigo relatamos a segunda ocorrência de duas espécies pouco conhecidas de Calvatia, registradas no bioma Cerrado do Brasil: C. oblongispora e C. nodulata. Descrições morfológicas detalhadas e ilustrações são fornecidas, incluindo micrografias eletrônicas de varredura de hifas e basidiósporos, bem como uma discussão sobre sua taxonomia e distribuição geográfica.(AU)

Second world record for two Calvatia species (Agaricaceae: Basidiomycota) / Segundo registro mundial para duas espécies de Calvatia (Agaricaceae: Basidiomycota)

Calvatia is a genus of gasteroid fungi, comprising about 47 species worldwide. In this paper we report the second worldwide occurrence of two poorly known species of Calvatia, recorded in the Cerrado biome of Brazil: C. oblongispora and C. nodulata. Detailed morphological descriptions and illustrations, including scanning electron micrographs of hyphae and basidiospores are provided, as well a discussion on their taxonomy and geographic distribution.

Calvatia é um gênero de fungos gasteroides que compreende cerca de 47 espécies em todo o mundo. Neste artigo relatamos a segunda ocorrência de duas espécies pouco conhecidas de Calvatia, registradas no bioma Cerrado do Brasil: C. oblongispora e C. nodulata. Descrições morfológicas detalhadas e ilustrações são fornecidas, incluindo micrografias eletrônicas de varredura de hifas e basidiósporos, bem como uma discussão sobre sua taxonomia e distribuição geográfica.

TcTI, a Kunitz-type trypsin inhibitor from cocoa associated with defense against pathogens.

Protease inhibitors (PIs) are important biotechnological tools of interest in agriculture. Usually they are the first proteins to be activated in plant-induced resistance against pathogens. Therefore, the aim of this study was to characterize a Theobroma cacao trypsin inhibitor called TcTI. The ORF has 740 bp encoding a protein with 219 amino acids, molecular weight of approximately 23 kDa. rTcTI was expressed in the soluble fraction of Escherichia coli strain Rosetta [DE3]. The purified His-Tag rTcTI showed inhibitory activity against commercial porcine trypsin. The kinetic model demonstrated that rTcTI is a competitive inhibitor, with a Ki value of 4.08 × 10-7 mol L-1. The thermostability analysis of rTcTI showed that 100% inhibitory activity was retained up to 60 °C and that at 70-80 °C, inhibitory activity remained above 50%. Circular dichroism analysis indicated that the protein is rich in loop structures and ß-conformations. Furthermore, in vivo assays against Helicoverpa armigera larvae were also performed with rTcTI in 0.1 mg mL-1 spray solutions on leaf surfaces, which reduced larval growth by 70% compared to the control treatment. Trials with cocoa plants infected with Mp showed a greater accumulation of TcTI in resistant varieties of T. cacao, so this regulation may be associated with different isoforms of TcTI. This inhibitor has biochemical characteristics suitable for biotechnological applications as well as in resistance studies of T. cacao and other crops.

Grassland fairy rings of Leucocalocybe mongolica represent the center of a rich soil microbial community.

BACKGROUND: The ecological phenomenon of fungal fairy rings is usually found in grasslands and caused by the growth of specific fairy ring fungi in soil. The fairy rings are classified into three zones (DARK, DEAD, and OUT), and they have the potential to increase crop yield. Among these fairy rings, distinct characteristics of type I fairy rings can be seen in the rings formed by Leucocalocybe mongolica (LM). Our studies addressed changes in the soil microbial structure due to LM fairy rings to enhance understand of this ecological phenomenon. METHODS: In the present study, we report the soil microbial analysis results (fungi and bacteria), including those of metabarcoding (16s rRNA, ITS), microbial quantity, and metagenomics surveys of soils collected from various fairy ring zones, of 6 LM fairy rings. All sampling sites cover the grasslands of Mongolian Plateau in China. RESULTS: First, we found through metabarcoding surveys that the difference in microbial diversity is relatively less in bacteria and that the abundance of fairy ring fungi (LM) is relatively high in DEAD zones. We also identified eight bacterial and fungal families, including Sphingobacteriaceae and Sphingomonadaceae that were enriched within the soils of fairy ring zones. Second, we found that the abundance of soil bacteria in the DEAD zones is sharply increased along with the growth of fairy ring fungi (LM). Third, we found through shotgun sequencing that fairy ring-infected zones, DARK and DEAD, exhibit greater genetic diversity than OUT zones. Finally, we showed that the fairy ring ecosystem is the center for a rich grassland microbial community. CONCLUSIONS: The reported data can improve our understanding of type I fairy rings and will be further insightful to the research on crop production.

Growth of Leucoagaricus gongylophorus Möller (Singer) and production of key enzymes in submerged and solid-state cultures with lignocellulosic substrates.

The aim of this study was to characterize the growth of the fungus Leucoagaricus gongylophorus LEU18496, isolated from the fungus garden of the nest of leaf cutter ants Atta mexicana. The fungus garden was cultivated in an artificial laboratory nest and the fungus further grown in submerged (SmC) and solid state (SSC) cultures with sugarcane bagasse, grass or model substrates containing CM-cellulose, xylan or lignin. The CO2 production rate with grass in SmC (Vmax 34.76 mg CO2 Lgas-1 day- 1) was almost four times than SSC (Vmax 9.49 mg CO2 Lgas-1 day- 1), while the production rate obtained in sugarcane bagasse in SmC (Vmax 16.02 mg CO2 Lgas-1 day- 1) was almost three times than that for SSC (Vmax 5.42 mg CO2 Lgas-1 day- 1). In addition, the fungus grew with defined carbon substrates mixtures in SmC, but at different rates, first xylan, followed by CM-cellulose and lignin. Endoglucanase and xylanase activities (U mgprotein-1) were detected in all cultures, the specific activity was higher in the fungus-garden, 5.2 and 1.8; followed by SSC-grass, 1.5 and 0.8, and SSC-bagasse, 0.9 and 0.8, respectively. Laccase activity in the fungus-garden was 44.8 U L- 1 and 10.9 U L- 1 in the SSC-grass. The gongylidia structures observed by environmental scanning electron microscopy were ca. 40 µm and the hyphae width ca. 5 µm. The results show that L. gongylophorus from A. mexicana have promising applications for the treatment of plant residues to release fermentable sugars and the production of high value lignocellulolytic enzymes such as endoglucanase, xylanase or laccases.

Biological activity of aqueous extracts of Southern Brazilian mushrooms.

This study aims to perform a bioactive analysis of five mushrooms collected in south of Brazil. The total phenol content of the extracts was equivalent to the antioxidant activity by ACAP assay. All extracts were able to inhibit the growth of Acinetobacter baumanni, and Auricularia auricula and Lactarius deliciosus extract showed the best antibacterial activity. In addition, no extract showed cytotoxic activity against VERO cells at the highest concentration evaluated (2500 µg/mL). Our results showed better antioxidant activity through the inhibition of the oxidation via peroxyl radical. It can be observed that all extracts were active against A. baumanni, and even moderately, all extracts could be inhibited of at least one of the bacteria used in the study. Added for these, the aqueous extracts showed no toxicity in VERO cells, highlighting the importance of research about the active compounds of mushrooms of the region.

Edible mushrooms as a novel protein source for functional foods.

Fast demographic growth has led to increasing interest in low-cost alternative protein sources to meet population needs. Consequently, scientific researchers have been focused on finding under-exploited sources of protein, alternative to those of animal origin. Usually plant proteins have been used for this purpose; however, most of them are not considered to be high quality due to their lack of some essential amino acids. Mushroom proteins usually have a complete essential amino acid profile, which may cover the dietetic requirements, as well as may have certain economic advantages as compared to animal and plant sources. Many mushrooms also have the ability to grow in agro-industrial waste, as submerged cultures, reaching high yields in a short period of time. Edible mushrooms can be processed to obtain a wide variety of food products enriched with high quality protein, which may have as well improved functional properties, giving them an added value. This review discusses the use of mushrooms as sustainable functional food.

Iron biofortification and availability in the mycelial biomass of edible and medicinal basidiomycetes cultivated in sugarcane molasses.

Basidiomycetes can bioaccumulate high iron contents, but there are few studies on iron availability from the mycelial biomass in order to support their use as an iron-enriched fungal food. This study aimed to evaluate the in vitro iron bioaccumulation and availability in the mycelial biomass of edible and medicinal basidiomycetes grown in two distinct culture media. Lentinus crinitus, Ganoderma lucidum, Schizophyllum commune, Pleurotus ostreatus, Pleurotus eryngii, Lentinula edodes, and Agaricus subrufescens were grown in liquid culture medium of malt extract or sugarcane molasses to obtain iron-bioaccumulated mycelial biomass. P. ostreatus was the fungus that most bioaccumulated iron, followed by S. commune, and P. eryngii; they also had the highest mycelial biomass growth and iron transfer from the culture medium to the mycelial biomass. Mycelial iron availability is species-specific, regardless of the culture medium and the iron bioaccumulation capacity of the fungus in the mycelial biomass. Mycelial biomass of S. commune, followed by G. lucidum, P. ostreatus, and P. eryngii, associated with molasses culture medium, are the best choice for the production of iron-enriched mycelial biomass.

Biodegradation of atrazine and ligninolytic enzyme production by basidiomycete strains.

BACKGROUND: Atrazine is one of the most widespread chlorinated herbicides, leaving large bulks in soils and groundwater. The biodegradation of atrazine by bacteria is well described, but many aspects of the fungal metabolism of this compound remain unclear. Thus, we investigated the toxicity and degradation of atrazine by 13 rainforest basidiomycete strains. RESULTS: In liquid medium, Pluteus cubensis SXS320, Gloelophyllum striatum MCA7, and Agaricales MCA17 removed 30, 37, and 38%, respectively, of initial 25 mg L- 1 of the herbicide within 20 days. Deficiency of nitrogen drove atrazine degradation by Pluteus cubensis SXS320; this strain removed 30% of atrazine within 20 days in a culture medium with 2.5 mM of N, raising three metabolites; in a medium with 25 mM of N, only 21% of initial atrazine were removed after 40 days, and two metabolites appeared in culture extracts. This is the first report of such different outcomes linked to nitrogen availability during the biodegradation of atrazine by basidiomycetes. The herbicide also induced synthesis and secretion of extracellular laccases by Datronia caperata MCA5, Pycnoporus sanguineus MCA16, and Polyporus tenuiculus MCA11. Laccase levels produced by of P. tenuiculus MCA11 were 13.3-fold superior in the contaminated medium than in control; the possible role of this enzyme on atrazine biodegradation was evaluated, considering the strong induction and the removal of 13.9% of the herbicide in vivo. Although 88% of initial laccase activity remained after 6 h, no evidence of in vitro degradation was observed, even though ABTS was present as mediator. CONCLUSIONS: This study revealed a high potential for atrazine biodegradation among tropical basidiomycete strains. Further investigations, focusing on less explored ligninolytic enzymes and cell-bound mechanisms, could enlighten key aspects of the atrazine fungal metabolism and the role of the nitrogen in the process.

The Possible Biotechnological Use of Edible Mushroom Bioproducts for Controlling Plant and Animal Parasitic Nematodes.

The present paper reviewed publications on the nematocidal activity of edible mushrooms (EM) and their potential use as sustainable tools for the control of parasitic nematodes affecting agriculture and livestock industry. Nematodes are organisms living in the soil and animals' guts where they may live as parasites severely affecting economically important crops and farm animals, thus causing economic losses to worldwide agriculture. Traditionally, parasitic nematodes have been controlled using commercial pesticides and anthelmintic (AH) drugs. Over the years, nematodes developed resistance to the AH drugs, reducing the usefulness of many commercial drugs. Also, the use of pesticides/anthelmintic drugs to control nematodes can have important negative impacts on the environment. Different EM have been not only used as food but also studied as alternative methods for controlling several diseases including parasitic nematodes. The present paper reviewed publications from the last decades about the nematocidal activity of EM and assessed their potential use as sustainable tools for the control of nematodes affecting agriculture and livestock industry. A reduced number of reports on the effect of EM against nematodes were found, and an even smaller number of reports regarding the potential AH activity of chemical compounds isolated from EM products were found. However, those studies have produced promising results that certainly deserve further investigation. It is concluded that EM, their fractions and extracts, and some compounds contained in them may have biotechnological application for the control of animal and plant parasitic nematodes.

Actualización del conocimiento del género Cyttaria Berk. (Cyttariales, Ascomycota) en Chile / Update of the knowledge of the genus Cyttaria Berk (Cyttariales, Ascomycota) in Chile

El género Cyttaria pertenece a la familia Cyttariaceae y sus especies son parásitos obligados de árboles del género Nothofagus. Se distribuye naturalmente en el hemisferio sur, encontrándose siete especies de Cyttaria presentes en nuestro país: C. berteroi, C. darwinii, C. espinosae, C. hariotii, C. hookeri, C. johowii y C. exigua, que comúnmente se conocen como "Digüeñes" y que tienen una gran importancia desde el punto de vista alimenticio, ya que han sido consumidos desde la prehistoria por pueblos originarios. En Chile se han realizado estudios sobre la taxonomía, ecología y propiedades medicinales de algunas especies del género Cyttaria y en esta revisión, se describen los caracteres macro y microscópicos e información relevante de las siete especies de este género presentes en nuestro país, de acuerdo a la literatura disponible y observaciones personales de la autora. Además, se presenta un resumen sobre los resultados de un estudio reciente de las propiedades bioactivas de las especies más consumidas en nuestro país. (AU)

The genus Cyttariabelongs to the family Cyttariaceae; its species are obligate parasites of trees of the genus Nothofagus. It is naturally distributed in the Southern Hemisphere, with seven species of Cyttariapresent in Chile: C. berteroi, C. darwinii, C. espinosae, C. hariotii, C. hookeri, C. johowiiand C. exigua, which are commonly known as "Digüeñes" and are of great nutritional importance, since they have been consumed from prehistory by native people. Studies have been carried out in Chile on the taxonomy, ecology and medicinal properties of some species of the genus Cyttaria. In this review, the macro and microscopic characteristics and relevant information of the seven species of this genus present in our country are described, according to the available literature and personal observations of the author. A summary of the results of a recent study of the bioactive properties of the most consumed species in our country is also presented. (AU)

Escovopsis kreiselii specialization to its native hosts in the fungiculture of the lower attine ant Mycetophylax morschi.

Parasite-host associations are widespread in nature and the fungus-growing ants are considered model organisms to study such interactions. These insects cultivate basidiomycetous fungi for food, which are threatened by mycotrophic fungi in the genus Escovopsis. Although recently described from colonies of the lower attine ant Mycetophylax morschi, the biology and pathogenicity of Escovopsis kreiselii are unknown. Herein, we evaluated the interaction of E. kreiselii with fungi cultivated by M. morschi (native hosts) and with a fungus cultivated by another attine ant species (non-native host). In addition, we examined the physical interactions between hypha of E. kreiselii and hypha from its native hosts using scanning electron microscopy. Escovopsis kreiselii inhibited the growth of fungal cultivars by 24% or more (with exception of one isolate), when compared to the fungal cultivars growing alone. Escovopsis kreiselii is attracted towards its native hosts through chemotaxis and inhibition occurs when there is physical contact with the hyphae of the fungal cultivar. As reported for Escovopsis parasites associated with leafcutter ants (higher attines), E. kreiselii growth increased in the presence of its native hosts, even before contact between both fungi occurred. In interactions with the fungal cultivar that is not naturally infected by E. kreiselii (non-native host), it caused inhibition but not at the same magnitude as in native hosts. Multiple lines of evidence suggest that E. kreiselii is an antagonist of the fungus cultivated by M. morschi and can chemically recognize such fungus.

Taxonomy and phylogeny of Macrolepiota: two new species from Brazil.

Macrolepiota is a poorly known genus in the Neotropics. In order to increase knowledge about this group, we collected specimens from the Atlantic Forest in southern and northeastern Brazil. Macrolepiota cyanolamellata and M. sabulosa from subtropical and tropical regions, respectively, are proposed as new species. We performed molecular phylogenetic analyses of the nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and the combined data set ITS + nuclear large subunit rDNA (28S) + RNA polymerase II second largest (RPB2), as well as morphological analyses. Two lineages with unique morphotypes were found. The species proposed were strongly supported as the sister lineage closely related to M. clelandii and M. subcitrophylla. Detailed descriptions and illustrations of their macro- and microscopic characters are provided.

Genetic characterization, evaluation of growth and production of biomass of strains from wild edible mushrooms of Lyophyllum of Central Mexico

The present study conducted a genetic characterization and determined growth rate and biomass production in solid and liquid media, using strains obtained from wild edible sporomes of Lyophyllum that grow in high mountains. Vegetative isolation was used to obtain a total of four strains, which were divided into two clades within the section Difformia: Lyophyllum sp. and Lyophyllum aff. shimeji. Growth rate and biomass production were influenced by both the culture media and the strains. In a potato dextrose agar medium, the strains presented a higher growth rate, while in a malt extract-peptone and yeast agar medium, the growth rate was lower, but with a higher biomass production that was equal to that in the malt extract-peptone and yeast liquid medium.(AU)

Genetic characterization, evaluation of growth and production of biomass of strains from wild edible mushrooms of Lyophyllum of Central Mexico

Abstract The present study conducted a genetic characterization and determined growth rate and biomass production in solid and liquid media, using strains obtained from wild edible sporomes of Lyophyllum that grow in high mountains. Vegetative isolation was used to obtain a total of four strains, which were divided into two clades within the section Difformia: Lyophyllum sp. and Lyophyllum aff. shimeji. Growth rate and biomass production were influenced by both the culture media and the strains. In a potato dextrose agar medium, the strains presented a higher growth rate, while in a malt extract-peptone and yeast agar medium, the growth rate was lower, but with a higher biomass production that was equal to that in the malt extract-peptone and yeast liquid medium.

Genetic characterization, evaluation of growth and production of biomass of strains from wild edible mushrooms of Lyophyllum of Central Mexico.

The present study conducted a genetic characterization and determined growth rate and biomass production in solid and liquid media, using strains obtained from wild edible sporomes of Lyophyllum that grow in high mountains. Vegetative isolation was used to obtain a total of four strains, which were divided into two clades within the section Difformia: Lyophyllum sp. and Lyophyllum aff. shimeji. Growth rate and biomass production were influenced by both the culture media and the strains. In a potato dextrose agar medium, the strains presented a higher growth rate, while in a malt extract-peptone and yeast agar medium, the growth rate was lower, but with a higher biomass production that was equal to that in the malt extract-peptone and yeast liquid medium.

A systematic overview of Descolea (Agaricales) in the Nothofagaceae forests of Patagonia.

The descolea clade includes species of ectomycorrhizal basidiomycetes in the genera Descolea, Setchelliogaster, Descomyces, and Timgrovea that are known primarily from the Southern Hemisphere. Taxa in this group produce basidiomes that range in morphology from typical epigeous mushrooms (Descolea) and secotioid taxa (Setchelliogaster) to fully gasteroid species (Descomyces and Timgrovea). High intraspecific morphological variation has been reported in several species within this clade, suggesting that careful morphological and molecular studies are needed to refine species concepts. Molecular analyses of fresh Patagonian collections in conjunction with taxonomic studies have confirmed high variability in key morphological features, including overall sporocarp form, spore shape and dimensions, universal veil remnants, and cuticle configuration. Based on our synthesis, we emend the genus Descolea to include sequestrate species. We describe the new sequestrate taxon Descolea inferna sp. nov. from Nothofagaceae forests in Patagonia and we propose Cortinarius squamatus as a synonym of our new combination Descolea brunnea. We also formalize the identity of Descolea pallida as a synonym of Descolea antarctica and provide new specimens of Cortinarius archeuretus, a species that has not been encountered since the original discovery during the expeditions of Roland Thaxter in 1905-1906. Here we re-describe and transfer this species to Descolea as D. archeureta. We also discuss diagnostic features that can be used to delimitate the four known South American taxa in the descolea clade.