Abstract Antarctica contains most of the glacial ice on the planet, a habitat that is largely unexplored by biologists. Recent warming in parts of Antarctica, particularly the Antarctic Peninsula region, is leading to widespread glacial retreat, releasing melt water and, potentially, contained biological material and propagules. In this study, we used a DNA metabarcoding approach to characterize Viridiplantae DNA present in Antarctic glacial ice. Ice samples from six glaciers in the South Shetland Islands and Antarctic Peninsula were analysed, detecting the presence of DNA representing a total of 16 taxa including 11 Chlorophyta (green algae) and five Magnoliophyta (flowering plants). The green algae may indicate the presence of a viable algal community in the ice or simply of preserved DNA, and the sequence diversity assigned included representatives of Chlorophyta not previously recorded in Antarctica. The presence of flowering plant DNA is most likely to be associated with pollen or tissue fragments introduced by humans.

Abstract We identified cultivable fungi present on the surface of five archaeological sealers’ artifacts from the beginning of the 19th century collected on Livingston Island, Antarctica. Twenty fungal isolates were recovered and identified using biology molecular methods as taxa of Antarctomyces, Linnemannia, Penicillium, Mortierella, Talaromyces, and Trichoderma. Penicillium was dominant on artifacts stored at 10 and 25 °C. In contrast, Antarctomyces, Linnemania, Mortierella, and Trichoderma occurred only on artifacts stored between 8 °C and 10 °C. Our results showed that the Antarctic artifacts harboured cosmopolitan mesophilic, cold-tolerant, and endemic psychrophilic fungal taxa. The mesophilic fungi might have contaminated the artifacts in situ, during sampling, transport, and/or storage in the laboratory collection or represent dormant but viable form capable to grow on the objects. However, the detection of cold-tolerant and endemic fungi shows that these fungi, when stored between 8 ° and 10 °C, continue growing on the objects, which may supply them with organic nutrients; this may accelerate degradation of artifacts in the collection. Preventive steps should be adopted to avoid further microbial contamination. Sterilised microbiological conditions can be followed during fieldwork and transportation to Brazil. The preventive protocol may represent a better alternative to avoid artifact microbial proliferation to preserve rare Antarctic archaeological heritage.

BACKGROUND Endophytic fungi, present mainly in the Ascomycota and Basidiomycota phyla, are associated with different plants and represent important producers of bioactive natural products. Brazil has a rich biodiversity of plant species, including those reported as being endemic. Among the endemic Brazilian plant species, Vellozia gigantea (Velloziaceae) is threatened by extinction and is a promising target to recover endophytic fungi. OBJECTIVE The present study focused on bioprospecting of bioactive compounds of the endophytic fungi associated with V. gigantea, an endemic, ancient, and endangered plant species that occurs only in the rupestrian grasslands of Brazil. METHODS The capability of 285 fungal isolates to produce antimicrobial and antimalarial activities was examined. Fungi were grown at solid-state fermentation to recover their crude extracts in dichloromethane. Bioactive extracts were analysed by chromatographic fractionation and NMR and displayed compounds with antimicrobial, antimycobacterial, and antimalarial activities. FINDINGS Five fungi produced antimicrobial and antimalarial compounds. Extracts of Diaporthe miriciae showed antifungal, antibacterial, and antimalarial activities; Trichoderma effusum displayed selective antibacterial activity against methicillin-resistant Staphylococcus aureus and Mycobacterium intracellulare; and three Penicillium species showed antibacterial activity. D. miriciae extract contained highly functionalised secondary metabolites, yielding the compound epoxycytochalasin H with high antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum, with an IC50 approximately 3.5-fold lower than that with chloroquine. MAIN CONCLUSION Our results indicate that V. gigantea may represent a microhabitat repository hotspot of potential fungi producers of bioactive compounds and suggest that endophytic fungal communities might be an important biological component contributing to the fitness of the plants living in the rupestrian grassland.

Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.

The diversity of yeasts collected from different sites in Antarctica (Admiralty Bay, King George Island and Port Foster Bay and Deception Island) and their ability to produce extracellular enzymes and mycosporines were studied. Samples were collected during the austral summer season, between November 2006 and January 2007, from the rhizosphere of Deschampsia antarctica, ornithogenic (penguin guano) soil, soil, marine and lake sediments, marine water and freshwater from lakes. A total of 89 isolates belonging to the following genera were recovered: Bensingtonia, Candida, Cryptococcus, Debaryomyces, Dioszegia, Exophiala, Filobasidium, Issatchenkia (Pichia), Kodamaea, Leucosporidium, Leucosporidiella, Metschnikowia, Nadsonia, Pichia, Rhodotorula, and Sporidiobolus, and the yeast-like fungi Aureobasidium, Leuconeurospora and Microglossum. Cryptococcus victoriae was the most frequently identified species. Several species isolated in our study have been previously reported to be Antarctic psychophilic yeasts, including Cr. antarcticus, Cr. victoriae, Dioszegia hungarica and Leucosporidium scottii. The cosmopolitan yeast species A. pullulans, C. zeylanoides, D. hansenii, I. orientalis, K. ohmeri, P. guilliermondii, Rh. mucilaginosa, and S. salmonicolor were also isolated. Five possible new species were identified. Sixty percent of the yeasts had at least one detectable extracellular enzymatic activity. Cryptococcus antarcticus, D. aurantiaca, D. crocea, D. hungarica, Dioszegia sp., E. xenobiotica, Rh. glaciales, Rh. laryngis, Microglossum sp. 1 and Microglossum sp. 2 produced mycosporines. Of the yeast isolates, 41.7% produced pigments and/or mycosporines and could be considered adapted to survive in Antarctica. Most of the yeasts had extracellular enzymatic activities at 4ºC and 20ºC, indicating that they could be metabolically active in the sampled substrates.

One hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive Brazilian plant species Ageratum myriadenia, Palicourea tetraphylla, Piptadenia adiantoides, and Trixis vauthieri. All fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. The crude extracts were tested in bioassay panels using Leishmania amazonensis, Trypanosoma cruzi, the enzyme trypanothione reductase (TryR) from Trypanosoma cruzi, and three human cancer cell lines. Thirty-three extracts (27.2%) exhibited at least one biological activity. Seventeen extracts (14%) were cytotoxic against one or more human cancer cell line with the IC50 values ranged of >0.2 to 25 µg/mL. Twenty-four extracts (19.8%) inhibited the activity of TryR, and three showed ability to inhibit the growth of T. cruzi above 60% and their IC50 values ranged among 1 to 10 µg/mL. Eleven extracts (9%) were able to inhibit the growth of L. amazonensis and showed with IC50 values ranged among 4.6 to 24.4 µg/mL. The endophytic fungi were identified as belonging to the genera Alternaria, Arthrinium, Cochliobolus, Colletotrichum, Penicillium, Fusarium, and Gibberella. An interesting result was obtained for the bioactive isolates UFMGCB 508, 537, 899 and 903, which were related to fungi associated with medicinal plants native to Asia, Australia, Africa, and Polynesia. These results indicate that bioactive plants living in Brazilian ecosystems are a potential host of endophytic fungi able to produce bioactive prototype molecules for drug development against neglected tropical diseases.

O potencial de Trametes villosa e Pycnoporus sanguineus de descolorir corantes têxteis reativos utilizados na manufatura de algodão no estado de Minas Gerais foi avaliado. Halos de crescimento e descoloração foram determinados em agar extrato malte (MEA) com 0,002g L-1 do corante. T. villosa descoloriu os 28 corantes testados e P. sanguineus apenas 9. A influência de condições de cultivo (agitação, concentração de corante e concentração de nitrogênio) na degradação do corante azul brilhante Drimaren foi avaliada durante crescimento dos fungos em meio líquido sintético. Agitação favoreceu a degradação e não foi observada repressão da descoloração pelo nitrogênio. Em cultura pura, T. villosa e P. sanguineus descoloriram efluente sintético constituído por uma mistura de dez corantes. Maior descoloração do efluente sintético foi observada no cultivo misto destes dois fungos. Este estudo evidenciou diferenças entre espécies de basidiomicetos tropicais na capacidade em degradar corantes reativos e reforçou o potencial deste grupo de fungos para a descoloração de efluentes têxteis.

The potential of Trametes villosa and Pycnoporus sanguineus to decolorize reactive textile dyes used for cotton manufacturing in the State of Minas Gerais, Brazil, was evaluated. Growth and decolorization halos were determined on malt extract agar containing 0.002g L-1 of the dye. T. villosa decolorized all 28 of the tested dyes while P. sanguineus decolorized only 9. The effect of culture conditions (shaking and dye and nitrogen concentration) on the degradation of Drimaren Brilliant Blue dye was evaluated during growth of the fungi in liquid synthetic medium. Shaking favored degradation and decolorization was not repressed by nitrogen. In pure culture, T. villosa and P. sanguineus decolorized synthetic effluent consisting of a mixture of 10 dyes. Higher decolorization of the synthetic effluent was observed when a mixed culture of the two fungi was used. This study demonstrated differences between tropical basidiomycete species in terms of their ability to degrade reactive dyes, and reinforces the potential of this group of fungi for the decolorization of textile effluents.

Uma cultura mixta e uma linhagem bacteriana pura foram isoladas de um bioreator para tratamento de tiocianato. As culturas removeram 5mM de tiocianato do meio em 36 horas. A cultura mixta foi capaz de tolerar concentrações superiores a 60mM. A eficiência da degradação de tiocianato diminuiu quando as células foram imobilizadas.

A mixed culture and a pure bacterial strain (BMV8) were isolated from a bioreactor for thiocyanate treatment. Both cultures removed 5 mM of thiocyanate from the medium in 36 hours. The mixed culture was able to tolerate concentrations up to 60 mM. The efficiency of thiocyanate degradation decreased when the cells were immobilized.