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We surveyed the diversity, distribution and ecology of non-lichenised fungal communities associated with the Antarctic lichens Usnea antarctica and Usnea aurantiaco - atra across Antarctica. The phylogenetic study of the 438 fungi isolates identified 74 taxa from 21 genera of Ascomycota , Basidiomycota and Zygomycota . The most abundant taxa were Pseudogymnoascus sp., Thelebolus sp., Antarctomyces psychrotrophicus and Cryptococcus victoriae , which are considered endemic and/or highly adapted to Antarctica. Thirty-five fungi may represent new and/or endemic species. The fungal communities displayed high diversity, richness and dominance indices; however, the similarity among the communities was variable. After discovering rich and diverse fungal communities composed of symbionts, decomposers, parasites and endemic and cold-adapted cosmopolitan taxa, we introduced the term “lichensphere”. We hypothesised that the lichensphere may represent a protected natural microhabitat with favourable conditions able to help non-lichenised fungi and other Antarctic life forms survive and disperse in the extreme environments of Antarctica.

We surveyed the diversity and capability of producing bioactive compounds from a cultivable fungal community isolated from the cold-arid, oligotrophic soil of continental Antarctica. A total of 115 fungal isolates were obtained and identified in 11 taxa of Aspergillus, Debaryomyces, Cladosporium, Pseudogymnoascus, Penicillium and Hypocreales. The phylogenetic analysis suggests that taxa of the genera Cladosporium, Pseudogymnoascus and Hypocreales may represent three new fungal species. The fungal community showed low diversity and richness, and high dominance indices. All fungal isolates were cultured, and extracts of Aspergillus sydowii, Penicillium allii-sativi, Penicillium brevicompactum, Penicillium chrysogenum and Penicillium rubens possessed antiviral, antibacterial, antifungal, antitumoral, herbicidal and antiprotozoal activities. Bioactive extracts were examined using 1H NMR detected the presence of secondary metabolites with interesting chemical shifts. Our results show that the fungi present in cold-oligotrophic soil from Antarctica included few dominant species, which may have important implications for understanding eukaryotic survival in cold-arid oligotrophic soils. We hypothesize that detailed further investigations may provide a greater understanding of the evolution of Antarctic fungi and their relationships with other organisms described in that region. Monitoring these unique fungal communities over time might also be useful as a model of climate changes in Antarctica. Additionally, different wild pristine bioactive fungal isolates found in continental Antarctic soil may represent a unique source to discover prototype molecules for use in drug and biopesticide discovery studies.

Fungi are generally easily dispersed, able to colonise a wide variety of substrata and can tolerate diverse environmental conditions. However, despite these abilities, the diversity of fungi in the Atacama Desert is practically unknown. Most of the resident fungi in desert regions are ubiquitous. Some of them, however, seem to display specific adaptations that enable them to survive under the variety of extreme conditions of these regions, such as high temperature, low availability of water, osmotic stress, desiccation, low availability of nutrients, and exposure to high levels of UV radiation. For these reasons, fungal communities living in the Atacama Desert represent an unknown part of global fungal diversity and, consequently, may be source of new species that could be potential sources for new biotechnological products. In this review, we focus on the current knowledge of the diversity, ecology, adaptive strategies, and biotechnological potential of the fungi reported in the different ecosystems of the Atacama Desert.

Fungal diversity in Antarctic seems to be greater than what is known and remains largely unexplored. In this study, we identified the endophytic symbiont yeasts associated with leaves of the angiosperms Deschampsia antarctica and Colobanthus quitensis living on King George Island, Antarctica using a culture-based approach. One hundred and twelve yeast isolates were obtained from the tissue of the different plants sampled. These yeasts were identified using sequencing of the D1/D2 domains of the LSU region of the rRNA gene as Cryptococcus victoriae , Cystobasidium laryngis , Rhodotorula mucilaginosa , Sporidiobolus ruineniae and Leucosporidium aff. golubevii . The psychrophilic yeast C. victoriae was the most abundant species associated with the two angiosperms. Cystobasidium laryngis occurs only in the leaves of D. antarctica . In contrast, R. mucilaginosa , S. ruineniae and L. aff. golubevii occurred only in C. quitensis . Phylogenetic analysis indicates the Antarctic endophytic yeast strains are closely related to taxa obtained from substrates located in different habitats of the world. However, the endophytic yeast C. victoriae was closely related to psychrophilic taxa isolated from Antarctica, but also from the Arctic, Alpine and Himalayan environments. The abundance of endophytic yeasts associated with Antarctic angiosperms suggests a possible symbiotic relationship with their plant hosts, which may provide shelter and growing conditions suitable for the yeasts’ survival, dispersal and colonization other Antarctic environments. In contrast, the endophytic yeasts might directly or indirectly promote the fitness of their host plants by producing metabolites beneficial to plant survival in the extreme environments of Antarctica.

We surveyed the distribution and diversity of fungi associated with eight macroalgae from Antarctica and their capability to produce bioactive compounds. The collections yielded 148 fungal isolates, which were identified using molecular methods as belonging to 21 genera and 50 taxa. The most frequent taxa were Geomyces species (sp.), Penicillium sp. and Metschnikowia australis . Seven fungal isolates associated with the endemic Antarctic macroalgae Monostroma hariotii (Chlorophyte) displayed high internal transcribed spacer sequences similarities with the psychrophilic pathogenic fungus Geomyces destructans . Thirty-three fungal singletons (66%) were identified, representing rare components of the fungal communities. The fungal communities displayed high diversity, richness and dominance indices; however, rarefaction curves indicated that not all of the fungal diversity present was recovered. Penicillium sp. UFMGCB 6034 and Penicillium sp. UFMGCB 6120, recovered from the endemic species Palmaria decipiens (Rhodophyte) and M. hariotii , respectively, yielded extracts with high and selective antifungal and/or trypanocidal activities, in which a preliminary spectral analysis using proton nuclear magnetic resonance spectroscopy indicated the presence of highly functionalised aromatic compounds. These results suggest that the endemic and cold-adapted macroalgae of Antarctica shelter a rich, diversity and complex fungal communities consisting of a few dominant indigenous or mesophilic cold-adapted species, and a large number of rare and/or endemic taxa, which may provide an interesting model of algal–fungal interactions under extreme conditions as well as a potential source of bioactive compounds.

We surveyed diversity patterns and engaged in bioprospecting for bioactive compounds of fungi associated with the endemic macroalgae, Monostroma hariotii and Pyropia endiviifolia, in Antarctica. A total of 239 fungal isolates were obtained, which were identified to represent 48 taxa and 18 genera using molecular methods. The fungal communities consisted of endemic, indigenous and cold-adapted cosmopolitan taxa, which displayed high diversity and richness, but low dominance indices. The extracts of endemic and cold-adapted fungi displayed biological activities and may represent sources of promising prototype molecules to develop drugs. Our results suggest that macroalgae along the marine Antarctic Peninsula provide additional niches where fungal taxa can survive and coexist with their host in the extreme conditions. We hypothesise that the dynamics of richness and dominance among endemic, indigenous and cold-adapted cosmopolitan fungal taxa might be used to understand and model the influence of climate change on the maritime Antarctic mycota.

The Sairecabur volcano (5971 m), in the Atacama Desert, is a high‐altitude extreme environment with high daily temperature variations, acidic soils, intense UV radiation, and low availability of water. Four different species of yeasts were isolated from this region using oligotrophic media, identified and characterized for their tolerance to extreme conditions. rRNA sequencing revealed high identity (>98%) to Cryptococcus friedmannii, Exophiala sp., Holtermanniella watticus, and Rhodosporidium toruloides. To our knowledge, this is the first report of these yeasts in the Atacama Desert. All isolates showed high resistance to UV‐C, UV‐B and environmental‐UV radiation, capacity to grow at moderate saline media (0.75–2.25 mol/L NaCl) and at moderate to cold temperatures, being C. friedmannii and H. watticus able to grow in temperatures down to −6.5°C. The presence of pigments, analyzed by Raman spectroscopy, correlated with UV resistance in some cases, but there is evidence that, on the natural environment, other molecular mechanisms may be as important as pigmentation, which has implications for the search of spectroscopic biosignatures on planetary surfaces. Due to the extreme tolerances of the isolated yeasts, these organisms represent interesting eukaryotic models for astrobiological purposes. In this work, yeasts were isolated from a high‐altitude volcano in the Atacama region. Tested for radiation resistance, cold‐tolerance and halophily, the isolates demonstrated a potential to be used as eukaryotic models of extremophiles.

A total of 564 isolates of endophytic fungi were recovered from the plants Deschampsia antarctica and Colobanthus quitensis collected from Antarctica. The isolates were screened against parasites Leishmania amazonensis and Trypanosoma cruzi and against the human tumour cell lines. Of the 313 fungal isolates obtained from D. antarctica and 251 from C. quitensis , 25 displayed biological activity. Nineteen extracts displayed leishmanicidal activity, and six inhibited the growth of at least one tumour cell line. These fungi belong to 19 taxa of the genera Alternaria , Antarctomyces , Cadophora , Davidiella , Helgardia , Herpotrichia , Microdochium , Oculimacula , Phaeosphaeria and one unidentified fungus. Extracts of 12 fungal isolates inhibited the proliferation of L. amazonesis at a low IC 50 of between 0.2 and 12.5 μg ml −1 . The fungus Phaeosphaeria herpotrichoides displayed only leishmanicidal activity with an IC 50 of 0.2 μg ml −1 , which is equivalent to the inhibitory value of amphotericin B. The extract of Microdochium phragmitis displayed specific cytotoxic activity against the UACC-62 cell line with an IC 50 value of 12.5 μg ml −1 . Our results indicate that the unique angiosperms living in Antarctica shelter an interesting bioactive fungal community that is able to produce antiprotozoal and antitumoral molecules. These molecules may be used to develop new leishmanicidal and anticancer drugs.

The emergence of open ocean global-scale studies provided important information about the genomics of oceanic microbial communities. Metagenomic analyses shed light on the structure of marine habitats, unraveling the biodiversity of different water masses. Many biological and environmental factors can contribute to marine organism composition, such as depth. However, much remains unknown about microbial communities’ taxonomic and functional features in different water layer depths. Here, we performed a metagenomic analysis of 76 publicly available samples from the Tara Ocean Project, distributed in 8 collection stations located in tropical or subtropical regions, and sampled from three layers of depth (surface water layer—SRF, deep chlorophyll maximum layer—DCM, and mesopelagic zone—MES). The SRF and DCM depth layers are similar in abundance and diversity, while the MES layer presents greater diversity than the other layers. Diversity clustering analysis shows differences regarding the taxonomic content of samples. At the domain level, bacteria prevail in most samples, and the MES layer presents the highest proportion of archaea among all samples. Taken together, our results indicate that the depth layer influences microbial sample composition and diversity.