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In the context of the virosphere, viral particles can compete for host cells. In this scenario, some viruses block the entry of exogenous virions upon infecting a cell, a phenomenon known as superinfection inhibition. The molecular mechanisms associated with superinfection inhibition vary depending on the viral species and the host, but generally, blocking superinfection ensures the genetic supremacy of the virus's progeny that first infects the cell. Giant amoeba-infecting viruses have attracted the scientific community's attention due to the complexity of their particles and genomes. However, there are no studies on the occurrence of superinfection and its inhibition induced by giant viruses. This study shows that mimivirus, moumouvirus, and megavirus, exhibit different strategies related to the infection of Acanthamoeba. For the first time, we have reported that mimivirus and moumouvirus induce superinfection inhibition in amoebas. Interestingly, megaviruses do not exhibit this ability, allowing continuous entry of exogenous virions into infected amoebas. Our investigation into the mechanisms behind superinfection blockage reveals that mimivirus and moumouvirus inhibit amoebic phagocytosis, leading to significant changes in the morphology and activity of the host cells. In contrast, megavirus-infected amoebas continue incorporating newly formed virions, negatively affecting the available viral progeny. This effect, however, is reversible with chemical inhibition of phagocytosis. This work contributes to the understanding of superinfection and its inhibition in mimivirus, moumouvirus, and megavirus, demonstrating that despite their evolutionary relatedness, these viruses exhibit profound differences in their interactions with their hosts.IMPORTANCESome viruses block the entry of new virions upon infecting a cell, a phenomenon known as superinfection inhibition. Superinfection inhibition in giant viruses has yet to be studied. This study reveals that even closely related viruses, such as mimivirus, moumouvirus, and megavirus, have different infection strategies for Acanthamoeba. For the first time, we have reported that mimivirus and moumouvirus induce superinfection inhibition in amoebas. In contrast, megaviruses do not exhibit this ability, allowing continuous entry of exogenous virions into infected amoebas. Our investigation shows that mimivirus and moumouvirus inhibit amoebic phagocytosis, causing significant changes in host cell morphology and activity. Megavirus-infected amoebas, however, continue incorporating newly formed viruses, affecting viral progeny. This research enhances our understanding of superinfection inhibition in these viruses, highlighting their differences in host interactions.

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The discovery of mimivirus in 2003 prompted the search for novel giant viruses worldwide. Despite increasing interest, the diversity and distribution of giant viruses is barely known. Here, we present data from a 2012-2022 study aimed at prospecting for amoebal viruses in water, soil, mud, and sewage samples across Brazilian biomes, using Acanthamoeba castellanii for isolation. A total of 881 aliquots from 187 samples covering terrestrial and marine Brazilian biomes were processed. Electron microscopy and PCR were used to identify the obtained isolates. Sixty-seven amoebal viruses were isolated, including mimiviruses, marseilleviruses, pandoraviruses, cedratviruses, and yaraviruses. Viruses were isolated from all tested sample types and almost all biomes. In comparison to other similar studies, our work isolated a substantial number of Marseillevirus and cedratvirus representatives. Taken together, our results used a combination of isolation techniques with microscopy, PCR, and sequencing and put highlight on richness of giant virus present in different terrestrial and marine Brazilian biomes.

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This study characterized cultivable fungi present in sediments obtained from Boeckella Lake, Hope Bay, in the north-east of the Antarctic Peninsula, and evaluated their production of enzymes and biosurfactants of potential industrial interest. A total of 116 fungal isolates were obtained, which were classified into 16 genera within the phyla Ascomycota, Basidiomycota and Mortierellomycota, in rank. The most abundant genera of filamentous fungi included Pseudogymnoascus, Pseudeurotium and Antarctomyces; for yeasts, Thelebolales and Naganishia taxa were dominant. Overall, the lake sediments exhibited high fungal diversity and moderate richness and dominance. The enzymes esterase, cellulase and protease were the most abundantly produced by these fungi. Ramgea cf. ozimecii, Holtermanniella wattica, Leucosporidium creatinivorum, Leucosporidium sp., Mrakia blollopis, Naganishia sp. and Phenoliferia sp. displayed enzymatic index > 2. Fourteen isolates of filamentous fungi demonstrated an Emulsification Index 24% (EI24%) ≥ 50%; among them, three isolates of A. psychrotrophicus showed an EI24% > 80%. Boeckella Lake itself is in the process of drying out due to the impact of regional climate change, and may be lost completely in approaching decades, therefore hosts a threatened community of cultivable fungi that produce important biomolecules with potential application in biotechnological processes.

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In this study, we evaluated the fungal diversity present associated with cores of Oligocene rocks using a DNA metabarcoding approach. We detected 940,969 DNA reads grouped into 198 amplicon sequence variants (ASVs) representing the phyla Ascomycota, Basidiomycota, Mortierellomycota, Chytridiomycota, Mucoromycota, Rozellomycota, Blastocladiomycota, Monoblepharomycota, Zoopagomycota, Aphelidiomycota (Fungi) and the fungal-like Oomycota (Stramenopila), in rank abundance order. Pseudogymnoascus pannorum, Penicillium sp., Aspergillus sp., Cladosporium sp., Aspergillaceae sp. and Diaporthaceae sp. were assessed to be dominant taxa, with 22 fungal ASVs displaying intermediate abundance and 170 being minor components of the assigned fungal diversity. The data obtained displayed high diversity indices, while rarefaction indicated that the majority of the diversity was detected. However, the diversity indices varied between the cores analysed. The endolithic fungal community detected using a metabarcoding approach in the Oligocene rock samples examined contains a rich and complex mycobiome comprising taxa with different lifestyles, comparable with the diversity reported in recent studies of a range of Antarctic habitats. Due to the high fungal diversity detected, our results suggest the necessity of further research to develop strategies to isolate these fungi in culture for evolutionary, physiological, and biogeochemical studies, and to assess their potential role in biotechnological applications.

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Aspergillus fumigatus is a common opportunistic pathogen in different animals, including birds such as penguins. For the first time, a fungal strain identified as A. fumigatus was isolated from soil in the nests of gentoo penguins, Pygoscelis papua, on Livingston Island, South Shetland Islands (maritime Antarctica). This isolate (A. fumigatus UFMGCB 11829) displayed a series of potentially pathogenic characteristics in vitro. We evaluated its detailed molecular taxonomy and submitted the A. fumigatus UFMGCB 11829 Antarctic strain to in vivo pathogenic modelling. The isolate was confirmed to represent A. fumigatus morphological and phylogenetic analysis showed that it was closely related to A. fumigatus sequences reported from animals, immunosuppressed humans, storage grains, plants and soils. The strain displayed the best mycelial growth and conidia production at 37 ºC; however, it was also able to grow and produce conidia at 15º, demonstrating its capability to survive and colonize penguin nest at least in the summer season in maritime Antarctica. In pathogenicity tests, healthy mice did not showed symptoms of infection; however, 50% lethality was observed in immunosuppressed mice that were inoculated with 106 and 107 spores. Lethality increased to 100% when inoculated with 108 spores. Our data highlight the potential pathogenicity of opportunistic A. fumigatus that may be present in the Antarctic, and the risks of both their further transfer within Antarctica and outwards to other continents, risks which may be exacerbated due global climatic changes.

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We assessed the fungal diversity present in snow sampled during summer in the north-west Antarctic Peninsula and the South Shetland Islands, maritime Antarctica using a metabarcoding approach. A total of 586,693 fungal DNA reads were obtained and assigned to 203 amplicon sequence variants (ASVs). The dominant phylum was Ascomycota, followed by Basidiomycota, Mortierellomycota, Chytridiomycota and Mucoromycota. Penicillium sp., Pseudogymnoascus pannorum, Coniochaeta sp., Aspergillus sp., Antarctomyces sp., Phenoliferia sp., Cryolevonia sp., Camptobasidiaceae sp., Rhodotorula mucilaginosa and Bannozyma yamatoana were assessed as abundant taxa. The snow fungal diversity indices were high but varied across the different locations sampled. Of the fungal ASVs detected, only 28 were present all sampling locations. The 116 fungal genera detected in the snow were dominated by saprotrophic taxa, followed by symbiotrophic and pathotrophic. Our data indicate that, despite the low temperature and oligotrophic conditions, snow can host a richer mycobiome than previously reported through traditional culturing studies. The snow mycobiome includes a complex diversity dominated by cosmopolitan, cold-adapted, psychrophilic and endemic taxa. While saprophytes dominate this community, a range of other functional groups are present.

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Consultations with children and their families are complex and require soft skills. However, there is a gap in the medical curriculum concerning these skills, especially as encounter training is often adult-centered. We developed, validated, and applied simulation scenarios that prioritize active participation of children to train soft skills in child-centered care for undergraduate medical students. This is a methodological study to develop three scenarios and a checklist of what is expected. The content was validated by 18 experts. A pre-test was carried out for adjustments. Then, the simulations were applied and evaluated by 18 medical undergraduate students. They included the participation of 6 pediatric simulated patients aged 9-12 years trained by a drama teacher. According to the results, the scenarios and checklist proved to be valid instruments in content terms (ICV-I > 0.8). The scripts were followed by the simulated pediatric patients, but they had difficulty mimicking a hypoactive state. Some were anxious, but everyone enjoyed participating in the feedback. The simulated parents had difficulty participating and giving space to the child's speech. Participants assessed that the simulations performed as they were proposed and, after experimenting them, felt more prepared. The simulations provided an opportunity for students to practice soft skills by interacting with children in a safe environment. Using children as simulated patients is feasible but presents some challenges. Our study has expanded the ways in which children's health content can be taught. We are investigating whether this training leads to better patient outcomes in real clinical settings.

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We studied the culturable fungal community recovered from deep marine sediments in the maritime Antarctic, and assessed their capabilities to produce exoenzymes, emulsifiers and metabolites with phytotoxic activity. Sixty-eight Ascomycota fungal isolates were recovered and identified. The most abundant taxon recovered was the yeast Meyerozyma guilliermondii, followed by the filamentous fungi Penicillium chrysogenum, P. cf. palitans, Pseudeurotium cf. bakeri, Thelebolus balaustiformis, Antarctomyces psychrotrophicus and Cladosporium sp. Diversity indices displayed low values overall, with the highest values obtained at shallow depth, decreasing to the deepest location sampled. Only M. guilliermondii and P. cf. palitans were detected in the sediments at all depths sampled, and were the most abundant taxa at all sample sites. The most abundant enzymes detected were proteases, followed by invertases, cellulases, lipases, carrageenases, agarases, pectinases and esterases. Four isolates showed good biosurfactant activity, particularly the endemic species A. psychrotrophicus. Twenty-four isolates of P. cf. palitans displayed strong phytotoxic activities against the models Lactuca sativa and Allium schoenoprasum. The cultivable fungi recovered demonstrated good biosynthetic activity in the production of hydrolytic exoenzymes, biosurfactant molecules and metabolites with phytotoxic activity, reinforcing the importance of documenting the taxonomic, ecological and biotechnological properties of fungi present in deep oceanic sediments of the Southern Ocean.

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Antarctica harbors a microbial diversity still poorly explored and of inestimable biotechnological value. Cold-adapted microorganisms can produce a diverse range of metabolites stable at low temperatures, making these compounds industrially interesting for biotechnological use. The present work investigated the biotechnological potential for antimicrobial and antitumor activity of filamentous fungi and bacteria isolated from marine sediment samples collected at Deception Island, Antarctica. A total of 89 microbial isolates were recovered from marine sediments and submitted to an initial screening for L-glutaminase with antitumoral activity and for antimicrobial metabolites. The isolates Pseudogymnoascus sp. FDG01, Pseudogymnoascus sp. FDG02, and Penicillium sp. FAD33 showed potential antiproliferative action against human pancreatic carcinoma cells while showing no toxic effect on non-tumor cells. The microbial extracts from unidentified three bacteria and four filamentous fungi showed antibacterial activity against at least one tested pathogenic bacterial strain. The isolate FDG01 inhibited four bacterial species, while the isolate FDG01 was active against Micrococcus luteus in the minimal inhibitory concentration of 0.015625 µg mL -1. The results pave the way for further optimization of enzyme production and characterization of enzymes and metabolites found and reaffirm Antarctic marine environments as a wealthy source of compounds potentially applicable in the healthcare and pharmaceutical industry.

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We assessed soil fungal and fungal-like diversity using metabarcoding in ornithogenically influenced soils around nests of the bird species Phalacrocorax atriceps, Macronectes giganteus, Pygoscelis antarcticus, and Pygoscelis adelie on the South Shetland Islands, maritime Antarctic. A total of 1,392,784 fungal DNA reads was obtained and assigned to 186 amplicon sequence variants (ASVs). The dominant fungal phylum was Ascomycota, followed by Basidiomycota, Chytridiomycota, Blastocladiomycota, Rozellomycota, Mortierellomycota, Monoblepharomycota, Aphelidiomycota, Basidiobolomycota, Mucoromycota, and the fungal-like Oomycota (Stramenopila), in rank order. Antarctomyces sp., Blastocladiomycota sp., Pseudogymnoascus pannorum, Microascaceae sp., Mortierella sp., Lobulomycetales sp., Sordariomycetes sp., Fungal sp., Rhizophydiales sp., Pseudeurotiaceae sp., Chytridiomycota sp. 1, Filobasidiella sp., Tausonia pullulans, Betamyces sp., and Leucosporidium sp. were the most abundant assigned taxa. The fungal assemblages present in the different ornithogenically influenced soils displayed different diversity indices. However, in general, we detected high fungal diversity and few taxa shared between the samples. Despite the polyextreme environmental conditions experienced in these Antarctic soils, the metabarcoding approach detected a rich and complex fungal community dominated by saprophytes, but with some pathogenic taxa also present. The community was dominated by psychrophilic and psychrotolerant taxa, some apparently endemic to Antarctica, and those identified only at higher taxonomic levels, which may represent currently undescribed fungi. The mycobiome detected included taxa characterized by different ecological roles, including saprotrophic, human- and animal-associated, phytopathogenic, mutualistic, and cosmopolitan. These fungi may potentially be dispersed by birds or in the air column over great distances, including between different regions within Antarctica and from South America, Africa, and Oceania.

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Microorganisms that inhabit the cold Antarctic environment can produce ligninolytic enzymes potentially useful in bioremediation. Our study focused on characterizing Antarctic bacteria and fungi from marine sediment samples of King George and Deception Islands, maritime Antarctica, potentially affected by hydrocarbon influence, able to produce enzymes for use in bioremediation processes in environments impacted with petroleum derivatives. A total of 168 microorganism isolates were obtained: 56 from sediments of King George Island and 112 from Deception Island. Among them, five bacterial isolates were tolerant to cell growth in the presence of diesel oil and gasoline and seven fungal were able to discolor RBBR dye. In addition, 16 isolates (15 bacterial and one fungal) displayed enzymatic emulsifying activities. Two isolates were characterized taxonomically by showing better biotechnological results. Psychrobacter sp. BAD17 and Cladosporium sp. FAR18 showed pyrene tolerance (cell growth of 0.03 g mL-1 and 0.2 g mL-1) and laccase enzymatic activity (0.006 UL-1 and 0.10 UL-1), respectively. Our results indicate that bacteria and fungi living in sediments under potential effect of hydrocarbon pollution may represent a promising alternative to bioremediate cold environments contaminated with polluting compounds derived from petroleum such as polycyclic aromatic hydrocarbons and dyes.

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Introduction Pituitary tumors account for 25% of all primary brain tumors and for 15% of overall intracranial expansive masses. Pituitary metastases, in contrast, are a rare condition, estimated as 1.8% of all resected sellar lesions. We present here a rare case of clear cell renal carcinoma metastasis to the pituitary gland. Case Report A 65-year-old patient with holocranial headache and diplopia, whose physical examination showed right eye abduction palsy and ipsilateral anisocoria. Magnetic resonance imaging (MRI) of the pituitary revealed a heterogeneous mass in T1 weighted imaging with mild peripheral contrast enhancement and considerable growth during follow-up. Prolactin levels were high and dropped to normal after use of cabergoline, but remained normal even after the medication was halted. Biopsy was compatible with clear cell renal carcinoma. After surgery, the patient underwent radiotherapy, which was effective in reducing the volume of the lesion. Discussion Only 25 cases of pituitary metastasis arising from the kidney were reported in the literature between the years of 1957 and 2018. Metastases can reach the pituitary through hematogenous spread, cerebrospinal fluid, and contiguous bony lesions. Clinical presentation varies from vague complaints such as fatigue or headache to more specific signs like polyuria and polydipsia, and 60% of cases have clinical manifestations. Conclusion Case reports of pituitary metastases are low worldwide, with only 25 case reports of kidney metastases in over a 60-year period. The rarity of the lesions and hormonal alterations due to pituitary stalk compression can mislead diagnosis, and some patients may even never be diagnosed regarding their lower life span. In this report, radiotherapy was effective postresection, and accounts for a treatment option. All these issues account for the relevance of these case reports.

Introdução Os tumores hipofisários representam 25% de todos os tumores cerebrais primários e 15% das massas expansivas intracranianas totais. As metástases hipofisárias, por outro lado, são uma condição rara, estimada em 1,8% de todas as lesões selares ressecadas. Apresentamos aqui um caso raro de metástase de carcinoma renal de células claras para a glândula pituitária. Relato de caso Paciente de 65 anos com cefaleia holocraniana e diplopia, cujo exame físico mostrou paralisia de abdução do olho direito e anisocoria ipsilateral. A ressonância magnética (RM) da hipófise revelou uma massa heterogênea na imagem ponderada em T1 com leve realce periférico de contraste e crescimento considerável durante o acompanhamento. Os níveis de prolactina estavam altos e caíram para o normal após o uso de cabergolina, mas permaneceram normais mesmo após a interrupção da medicação. A biópsia foi compatível com carcinoma renal de células claras. Após a cirurgia, o paciente foi submetido à radioterapia, que foi eficaz na redução do volume da lesão. Discussão Apenas 25 casos de metástase hipofisária originada do rim foram relatados na literatura entre os anos de 1957 e 2018. As metástases podem atingir a hipófise por meio de disseminação hematogênica, líquido cefalorraquidiano e lesões ósseas contíguas. A apresentação clínica varia de queixas vagas, como fadiga ou dor de cabeça, a sinais mais específicos, como poliúria e polidipsia, e 60% dos casos têm manifestações clínicas. Conclusão Os relatos de casos de metástases hipofisárias são baixos em todo o mundo, com apenas 25 relatos de casos de metástases renais em um período de mais de 60 anos. A raridade das lesões e alterações hormonais devido à compressão do pedúnculo hipofisário podem enganar o diagnóstico, e alguns pacientes podem nunca ser diagnosticados em relação à sua menor expectativa de vida. Neste relato, a radioterapia foi eficaz após a ressecção e representa uma opção de tratamento. Todas essas questões são responsáveis pela relevância desses relatos de caso.

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This study aimed to evaluate the genomic profile of the Antarctic marine Curtobacterium sp. CBMAI 2942, as well as to optimize the conditions for chitinase production and antifungal potential for biological control. Assembly and annotation of the genome confirmed the genomic potential for chitinase synthesis, revealing two ChBDs of chitin binding (Chi C). The optimization enzyme production using an experimental design resulted in a 3.7-fold increase in chitinase production. The chitinase enzyme was identified by SDS-PAGE and confirmed through mass spectrometry analysis. The enzymatic extract obtained using acetone showed antifungal activity against the phytopathogenic fungus Aspergillus sp. series Nigri CBMAI 1846. The genetic capability of Curtobacterium sp. CBMAI 2942 for chitin degradation was confirmed through genomic analysis. The basal culture medium was adjusted, and the chitinase produced by this isolate from Antarctica showed significant inhibition against Aspergillus sp. Nigri series CBMAI 1846, which is a tomato phytopathogenic fungus. This suggests that this marine bacterium could potentially be used as a biological control of agricultural pests.

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Snow is a unique microhabitat, despite being a harsh environment, multiple life forms have adapted to survive in it. While algae, bacteria and fungi are dominant microorganisms in Antarctic snow, little is known about other organisms that may be present in this habitat. We used metabarcoding to investigate DNA sequence diversity of non-fungal eukaryotes present in snow obtained from six different sites across the Maritime Antarctica. A total of 20 taxa were assigned to obtained sequences, representing five Kingdoms (Chromista, Protozoa, Viridiplantae and Metazoa) and four phyla (Ciliophora, Cercozoa, Chlorophyta and Cnidaria). The highest diversity indices were detected in Trinity Peninsula followed by Robert Island, Arctowski Peninsula, Deception Island, King George Island and Snow Island. The most abundant assignments were to Trebouxiophyceae, followed by Chlamydomonas nivalis and Chlamidomonadales. No taxa were detected at all sites. Three potentially new records for Antarctica were detected: two Ciliophora (Aspidisca magna and Stokesia sp.) and the green algae Trebouxia potteri. Our data suggested that similarities found between the sites may be more related with snow physicochemical properties rather than geographic proximity or latitude. This study provides new insights into the diversity and distribution of eukaryotic organisms in Antarctic snow.

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Ten yeast isolates representing four candidate novel species of the genus Teunomyces were obtained from different species of mushrooms and drosophilids collected in an Amazonian Forest biome in Brazil. Sequence analyses of the ITS 5.8S region and the D1/D2 domains of the large subunit rRNA gene showed that four isolates were phylogenetically related to Teunomyces stri, two isolates related to Teunomyces atbi, two isolates related to Teunomyces aglyptinius, and another two isolates related to Teunomyces aglyptinius, Teunomyces barrocoloradensis, Teunomyces gatunensis and Teunomyces stri. The four novel species differ by 3 % or more of sequence divergence in D1/D2 domains from their closest relatives. These species were isolated from basidiocarps of the mushrooms Marasmiellus volvatus, Tricholomopsis aurea, Hydropus sp. and Favolus tenuiculus, or drosophilids feeding on these substrates. The names Teunomyces gombertii f.a., sp. nov. (holotype CBS 16168T; Mycobank MB849065), Teunomyces landelliae f.a., sp. nov. (holotype =CBS 16169T; Mycobank MB 849066), Teunomyces ledahaglerae f.a., sp. nov. (holotype CBS 16170T; Mycobank MB 849067) and Teunomyces paulamoraisiae f.a., sp. nov. (holotype CBS 16120T; Mycobank MB 849068) are proposed for these species.

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The postharvest disease popularly known as gray mold is considered one of the most limiting factors strawberry fruit production. The most effective way to control this disease is still the use of chemical fungicides. However, other alternative sources of control are being explored. Among these, psychrophilic yeasts adapted to extreme conditions, such as those found in the Antarctic region, may have great potential for use as biocontrol agents. Thus, the present study aimed to select psychrotolerant yeasts obtained from Antarctic region and to evaluate their potential for biocontrol under gray mold, caused by Botrytis cinerea in strawberries stored at low temperature. For this, 20 potential antagonist yeasts were evaluated in vitro (thermotolerance and enzymatic) assays. Debaryomyces hansenii, Rhodotorula mucilaginosa and Dioszegia hungarica were selected for growing in strawberry juice. However, only D. hansenii was selected for in vivo studies and showed a reduction in the incidence of gray mold by 82% for the tests performed on injury and 86% for the tests on non-injured fruits treated by immersion bath. Thus, demonstrating that the selection of this cold-adapted Antarctic yeast can be a promising strategy as a biocontrol agent used to curb the development of gray mold in strawberry fruits.

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Four isolates of Spathaspora species were recovered from rotting wood collected in two Brazilian Amazonian biomes. The isolates produced unconjugated allantoid asci with a single elongated ascospore with curved ends. Sequence analysis of the ITS-5.8S region and the D1/D2 domains of the large subunit rRNA gene showed that the isolates represent two different novel Spathaspora species, phylogenetically related to Sp. boniae. Two isolates were obtained from rotting wood collected in two different sites of the Amazonian forest in the state of Pará. The name Spathaspora brunopereirae sp. nov. is proposed to accommodate these isolates. The holotype of Spathaspora brunopereirae sp. nov. is CBS 16119T (MycoBank MB846672). The other two isolates were obtained from a region of transition between the Amazonian forest and the Cerrado ecosystem in the state of Tocantins. The name Spathaspora domphillipsii sp. nov. is proposed for this novel species. The holotype of Spathaspora domphillipsii sp. nov. is CBS 14229T (MycoBank MB846697). Both species are able to convert d-xylose into ethanol and xylitol, a trait with biotechnological applications.

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We studied the fungal diversity present in soils sampled along a deglaciated chronosequence from para- to periglacial conditions on James Ross Island, north-east Antarctic Peninsula, using DNA metabarcoding. A total of 88 amplicon sequence variants (ASVs) were detected, dominated by the phyla Ascomycota, Basidiomycota and Mortierellomycota. The uncommon phyla Chytridiomycota, Rozellomycota, Monoblepharomycota, Zoopagomycota and Basidiobolomycota were detected. Unknown fungi identified at higher hierarchical taxonomic levels (Fungal sp. 1, Fungal sp. 2, Spizellomycetales sp. and Rozellomycotina sp.) and taxa identified at generic and specific levels (Mortierella sp., Pseudogymnoascus sp., Mortierella alpina, M. turficola, Neoascochyta paspali, Penicillium sp. and Betamyces sp.) dominated the assemblages. In general, the assemblages displayed high diversity and richness, and moderate dominance. Only 12 of the fungal ASVs were detected in all chronosequence soils sampled. Sequences representing saprophytic, pathogenic and symbiotic fungi were detected. Based on the sequence diversity obtained, Clearwater Mesa soils contain a complex fungal community, including the presence of fungal groups generally considered rare in Antarctica, with dominant taxa recognized as cold-adapted cosmopolitan, endemic, saprotrophic and phytopathogenic fungi. Clearwater Mesa ecosystems are impacted by the effects of regional climatic changes, and may provide a natural observatory to understand climate change effects over time.

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Rupestrian grasslands are vegetation complexes of the Cerrado biome (Brazilian savanna), exhibiting simultaneously great biodiversity and important open-pit mining areas. There is a strong demand for the conservation of remaining areas and restoration of degraded. This study evaluated, using next-generation sequencing, the diversity and ecological aspects of soil fungal communities in ferruginous rupestrian grassland areas preserved and degraded by bauxite mining in Brazil. In the preserved and degraded area, respectively, 565 and 478 amplicon sequence variants (ASVs) were detected. Basidiomycota and Ascomycota comprised nearly 72% of the DNA, but Ascomycota showed greater abundance than Basidiomycota in the degraded area (64% and 10%, respectively). In the preserved area, taxa of different hierarchical levels (Agaromycetes, Agaricales, Mortierelaceae, and Mortierella) associated with symbiosis and decomposition were predominant. However, taxa that colonize environments under extreme conditions and pathogens (Dothideomycetes, Pleoporales, Pleosporaceae, and Curvularia) prevailed in the degraded area. The degradation reduced the diversity, and modified the composition of taxa and predominant ecological functions in the community. The lack of fungi that facilitate plant establishment and development in the degraded area suggests the importance of seeking the restoration of this community to ensure the success of the ecological restoration of the environment. The topsoil of preserved area can be a source of inocula of several groups of fungi important for the restoration process but which occur in low abundance or are absent in the degraded area.

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Located 1140 km from the South American coastline in the South Atlantic Ocean and with an age of 4 million years, Trindade Island is the most recent volcanic component of Brazilian territory. Its original native vegetation has been severely damaged by human influence, in particular through the introduction of exotic grazing animals such as goats. However, since the complete eradication of goats and other feral animals in the late 1990s, the island's vegetation has been recovering, and even some endemic species that had been considered extinct have been rediscovered. In this study, we set out to characterize the contemporary cryptic diversity in soils of the recovering native forest of Trindade Island using metabarcoding by high throughput sequencing (HTS). The sequence diversity obtained was dominated by microorganisms, including three domains (Bacteria, Archaea, and Eukarya) and five kingdoms (Fungi, Metazoa, Protozoa, Chromista, and Viridiplantae). Bacteria were represented by 20 phyla and 116 taxa, with Archaea by only one taxon. Fungi were represented by seven phyla and 250 taxa, Viridiplantae by five phyla and six taxa, Protozoa by five phyla and six taxa, Metazoa by three phyla and four taxa and Chromista by two phyla and two taxa. Even after the considerable anthropogenic impacts and devastation of the island's natural forest, our sequence data reveal the presence of a rich and complex diversity of microorganisms, invertebrates, and plants and provide important baseline biodiversity information that will contribute to ecological restoration efforts on the island.

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