23 results on '"Gonçalves VN"'
Search Results
2. Biocontrol mechanisms of the Antarctic yeast Debaryomyces hansenii UFT8244 against post-harvest phytopathogenic fungi of strawberries.
- Author
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Ferreira EMS, Garmendia G, Gonçalves VN, Silva JFMD, Convey P, Rosa LH, Vero S, and Pimenta RS
- Subjects
- Rhizopus physiology, Rhizopus drug effects, Plant Diseases microbiology, Plant Diseases prevention & control, Chitinases metabolism, Pest Control, Biological methods, Antarctic Regions, Debaryomyces physiology, Biological Control Agents pharmacology, Fragaria microbiology, Botrytis drug effects, Botrytis physiology
- Abstract
The use of yeasts has been explored as an efficient alternative to fungicide application in the treatment and prevention of post-harvest fruit deterioration. Here, we evaluated the biocontrol abilities of the Antarctic yeast strain Debaryomyces hansenii UFT8244 against the post-harvest phytopathogenic fungi Botrytis cinerea and Rhizopus stolonifer for the protection and preservation of strawberry fruit. The strongest inhibition of germination of B. cinerea (57%) was observed at 0 °C, followed by 40% at 25 °C. In addition, germ tubes and hyphae of B. cinerea were strongly surrounded and colonized by D. hansenii. Production of the enzymes β-1,3-glucanase, chitinase and protease by D. hansenii was detected in the presence of phytopathogenic fungus cell walls. The activity of β-1,3-glucanase was highest on day 12 of incubation and remained high until day 15. Chitinase and protease activities reached their highest levels on the day 15 of incubation. D. hansenii additionally demonstrated the ability to resist oxidative stress. Our data demonstrated that the main biocontrol mechanisms displayed by D. hansenii were the control of phytopathogenic fungal spore germination, production of antifungal enzymes and resistance to oxidative stress. We conclude that isolate D. hansenii UFT8422 should be further investigated for use at commercial scales at low temperatures.
- Published
- 2024
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3. Fungal and fungal-like diversity present in ornithogenically influenced maritime Antarctic soils assessed using metabarcoding.
- Author
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Gonçalves VN, Pimenta RS, Lopes FAC, Santos KCR, Silva MC, Convey P, Câmara PEAS, and Rosa LH
- Subjects
- Antarctic Regions, Animals, Birds microbiology, Biodiversity, Phylogeny, Soil chemistry, Soil Microbiology, Fungi classification, Fungi genetics, Fungi isolation & purification, DNA Barcoding, Taxonomic, DNA, Fungal genetics
- Abstract
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., (© 2024 Wiley‐VCH GmbH.)
- Published
- 2024
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4. Endolithic Fungal Diversity in Antarctic Oligocene Rock Samples Explored Using DNA Metabarcoding.
- Author
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Rabelo NG, Gonçalves VN, Carvalho MA, Scheffler SM, Santiago G, Sucerquia PA, Oliveira FS, Campos LP, Lopes FAC, Santos KCR, Silva MC, Convey P, Câmara PEAS, and Rosa LH
- Abstract
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.
- Published
- 2024
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5. Pathogenic potential of an environmental Aspergillus fumigatus strain recovered from soil of Pygoscelis papua (Gentoo penguins) colony in Antarctica.
- Author
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Gonçalves VN, Amorim SS, da Costa MC, de Assis Santos D, Convey P, and Rosa LH
- Subjects
- Animals, Antarctic Regions, Mice, Bird Diseases microbiology, Virulence, Spheniscidae microbiology, Aspergillus fumigatus genetics, Aspergillus fumigatus isolation & purification, Aspergillus fumigatus classification, Aspergillus fumigatus pathogenicity, Soil Microbiology, Phylogeny, Aspergillosis microbiology, Aspergillosis veterinary
- Abstract
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 10
6 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., (© 2024. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)- Published
- 2024
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6. Selection of Antarctic yeasts as gray mold biocontrol agents in strawberry.
- Author
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Ferreira EMS, Garmendia G, Gonçalves VN, da Silva JFM, Rosa LH, Vero S, and Pimenta RS
- Subjects
- Antarctic Regions, Fungi, Yeasts, Fragaria, Fungicides, Industrial pharmacology
- Abstract
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., (© 2023. The Author(s), under exclusive licence to Springer Nature Japan KK, part of Springer Nature.)
- Published
- 2023
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7. Soil Fungal Diversity and Ecology Assessed Using DNA Metabarcoding along a Deglaciated Chronosequence at Clearwater Mesa, James Ross Island, Antarctic Peninsula.
- Author
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Gonçalves VN, Lirio JM, Coria SH, Lopes FAC, Convey P, de Oliveira FS, Carvalho-Silva M, Câmara PEAS, and Rosa LH
- Abstract
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.
- Published
- 2023
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8. Diversity and ecology of fungal assemblages present in lake sediments at Clearwater Mesa, James Ross Island, Antarctica, assessed using metabarcoding of environmental DNA.
- Author
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Gonçalves VN, de Souza LMD, Lirio JM, Coria SH, Lopes FAC, Convey P, Carvalho-Silva M, de Oliveira FS, Câmara PEAS, and Rosa LH
- Subjects
- Antarctic Regions, Ecosystem, Lakes microbiology, Chytridiomycota genetics, DNA, Environmental
- Abstract
We detected the fungal assemblages present in lake sediments on James Ross Island, Antarctica, using DNA metabarcoding. A total of 132 amplicon sequence variants (ASVs) were assigned, dominated by taxa of the phyla Ascomycota, Basidiomycota, Mortierellomycota and Mucoromycota. The less common phyla Chytridiomycota, Rozellomycota, Monoblepharomycota, Basidiobolomycota, Aphelidiomycota and the fungus-like Straminopila were also detected. Fungal sp. 1, Fungal sp. 2, Spizellomycetales sp. 1, Rozellomycotina sp. 1, Talaromyces rubicundus and Betamyces sp. dominated the assemblages. In general, the assemblages displayed high diversity and richness, and moderate dominance. Saprophytic, pathogenic and symbiotic fungi were detected. The metabarcoding data indicated that Antarctic lakes may represent a hotspot of fungal diversity in Antarctica. The sediments of these lakes may accumulate different fungal fragments and active fungal mycelia and their propagules, deposited over long periods of time. Lakes in the Antarctic Peninsula region are sensitive environments threatened by the effects of regional climatic changes. The abundance of sequences of little-known Rozellomycota and Chytridiomycota (Spizellomycetales) taxa in these ecosystems highlights the need for further studies to identify if they are metabolically active in the sediments and whether they have potentially pathogenic capabilities., (Copyright © 2022 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2022
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9. Does maritime Antarctic permafrost harbor environmental fungi with pathogenic potential?
- Author
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da Silva TH, Queres Gomes EC, Gonçalves VN, da Costa MC, Valério AD, de Assis Santos D, Johann S, Convey P, Rosa CA, and Rosa LH
- Subjects
- Antarctic Regions, Antifungal Agents, Fungi, Humans, Rhodotorula, Penicillium, Permafrost
- Abstract
We assessed the potentially pathogenic fungi present in Antarctic permafrost and the overlying active layer on King George, Robert, Livingston and Deception Islands in the South Shetland Islands archipelago, maritime Antarctica. Permafrost and active layer sub-samples were incubated at 37 °C to select fungi able to grow inside the human body. A total of 67 fungal isolates were obtained, 27 from the permafrost and 40 from the active layer. These represented 18 taxa of the genera Alternaria, Aspergillus, Curvularia, Penicillium, Rhodotorula and Talaromyces. The majority of fungi detected occurred exclusively either in the permafrost or the active layer at each site. Only Aspergillus thermomutatus, Penicillium cf. chrysogenum and Rhodotorula cf. mucilaginosa were present in both permafrost and active layer samples from the same site. The yeast R. cf. mucilaginosa was recovered from both in at least two sites. The genus Penicillium was the most abundant and widely distributed genus in both permafrost and active layer samples across the sites sampled. All fungal isolates were screened using enzymatic, pH and antifungal assays to identify their virulence potential. Aspergillus hiratsukae, A. thermomutatus and R. cf. mucilaginosa, known human opportunistic fungi, were identified, displayed phospholipase, esterase, proteinase and hemolytic activities. All three also displayed the ability to grow at 40°, 45° and/or 50 °C and resistance to fluconazole and itraconazole; additionally, R. cf. mucilaginosa showed resistance to amphotericin B and viability after 100 d at -80 °C. A. thermomutatus UFMGCB 17415 killed the entire larvae of Tenebrio molitor in six days and R. cf. mucilaginosa UFMGCB 17448 and 17473 in three and four days, respectively. The melting of maritime Antarctic permafrost as a result of climate change may threaten the release of wild strains of pathogenic fungi geographically isolated for long time, which may in turn be transported within and beyond Antarctica by different biological and non-biological vectors., Competing Interests: Declaration of competing interest All of the authors contributed substantially to the present research, which was prepared as an original article (Does maritime Antarctic permafrost harbor environmental fungi with pathogenic potential?) as a submission for publication in Fungal Biology. There is no conflict of interest among the authors., (Copyright © 2022 British Mycological Society. All rights reserved.)
- Published
- 2022
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10. Diversity and ecology of cultivable fungi isolated from the thermal soil gradients in Deception Island, Antarctica.
- Author
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Figueredo HM, Gonçalves VN, Godinho VM, Lopes DV, Oliveira FS, and Rosa LH
- Subjects
- Aged, Antarctic Regions, Ascomycota, Fungi, Humans, Islands, Soil Microbiology, Soil
- Abstract
We surveyed the diversity of cultivable fungi isolated from cold and hot volcanic soils of Deception Island, Antarctica. Seventy-four fungal isolates were identified; these belonged to 17 taxa in the genera Aspergillus, Penicillium, Pseudogymnoascus, Purpureocillium, and Mortierella. The fungal assemblages showed low diversity, richness, and dominance indices. The Aspergillus taxa were dominant in the soils at 0 °C, 50 °C, and 100 °C. Aspergillus lacticoffeatus, Aspergillus cf. ruber, Penicillium citrinun, and Purpureocillium sodanum were present only in soils having a temperature of 100 °C. Aspergillus calidoustus was present in all thermal soils and displayed the highest densities. The majority of fungi displayed mesophilic behavior; however, different isolates of Aspergillus lacticoffeatus and Aspergillus niger were able to grow at 50 °C; these are phylogenetically close to the causative agents of aspergillosis in immunocompromised individuals. Deception Island perhaps represents one of the most visited regions in Antarctica and the tourism there has increased over the last 20 years, especially by elderly tourists, probably with weak immune systems, come in contact with the resident microorganisms, including the thermo-resistant opportunistic Aspergillus species.
- Published
- 2020
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11. Diversity, Distribution, and Ecology of Fungi in the Seasonal Snow of Antarctica.
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de Menezes GCA, Amorim SS, Gonçalves VN, Godinho VM, Simões JC, Rosa CA, and Rosa LH
- Abstract
We characterized the fungal community found in the winter seasonal snow of the Antarctic Peninsula. From the samples of snow, 234 fungal isolates were obtained and could be assigned to 51 taxa of 26 genera. Eleven yeast species displayed the highest densities; among them, Phenoliferia glacialis showed a broad distribution and was detected at all sites that were sampled. Fungi known to be opportunistic in humans were subjected to antifungal minimal inhibition concentration. Debaryomyces hansenii , Rhodotorula mucilaginosa , Penicillium chrysogenum , Penicillium sp. 3, and Penicillium sp. 4 displayed resistance against the antifungals benomyl and fluconazole. Among them, R. mucilaginosa isolates were able to grow at 37 °C. Our results show that the winter seasonal snow of the Antarctic Peninsula contains a diverse fungal community dominated by cosmopolitan ubiquitous fungal species previously found in tropical, temperate, and polar ecosystems. The high densities of these cosmopolitan fungi suggest that they could be present in the air that arrives at the Antarctic Peninsula by air masses from outside Antarctica. Additionally, we detected environmental fungal isolates that were resistant to agricultural and clinical antifungals and able to grow at 37 °C. Further studies will be needed to characterize the virulence potential of these fungi in humans and animals.
- Published
- 2019
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12. The diversity, distribution, and pathogenic potential of cultivable fungi present in rocks from the South Shetlands archipelago, Maritime Antarctica.
- Author
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Alves IMS, Gonçalves VN, Oliveira FS, Schaefer CEGR, Rosa CA, and Rosa LH
- Subjects
- Antarctic Regions, Climate Change, Biodiversity, Fungi classification, Fungi genetics, Fungi isolation & purification, Fungi metabolism, Phylogeny, Soil Microbiology
- Abstract
We studied the molecular taxonomy and diversity of cultivable rock fungi from Antarctic islands. From 50 rock samples, 386 fungal isolates were obtained and identified as 33 taxa of 20 genera. The genera Cladophialophora, Cladosporium, Cyphellophora, Eichleriella, Paracladophialophora, and Penicillium displayed the highest densities. Ecological diversity indices showed that the fungal assemblages are diverse and rich with low dominance. The genera Cladophialophora, Cladosporium, and Penicillium showed a broad distribution from rocks of the various islands. One hundred and fifty-nine fungi, grown at 37 °C, were identified as Penicillium chrysogenum, Fusarium sp., and Rhodotorula mucilaginosa. One hundred and three fungi displayed haemolytic activity, 81 produced proteinase, 9 produced phospholipase, and 25 presented dimorphism and a spore diameter ≤ 4 µm. The Antarctic Peninsula region appears to be under the effects of global climate changes, which may expose and accelerate the rock's weathering processes, and expose and release cryptic fungi and other microbes, especially those with innate pathogenic potential, previously arrested in rocks. Consequently, these rocks and their particles may represent a vehicle for the dispersal of microbial propagules, including those able to spread pathogens, along, across, and out of Antarctica.
- Published
- 2019
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13. Fungal diversity in the Atacama Desert.
- Author
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Santiago IF, Gonçalves VN, Gómez-Silva B, Galetovic A, and Rosa LH
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- Adaptation, Physiological, Chile, Ecology, Ecosystem, Fungi isolation & purification, Fungi metabolism, Models, Biological, Biodiversity, Desert Climate, Fungi classification, Soil Microbiology
- Abstract
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.
- Published
- 2018
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14. Pathogenic potential of environmental resident fungi from ornithogenic soils of Antarctica.
- Author
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de Sousa JRP, Gonçalves VN, de Holanda RA, Santos DA, Bueloni CFLG, Costa AO, Petry MV, Rosa CA, and Rosa LH
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- Amphotericin B pharmacology, Animals, Antarctic Regions, Antifungal Agents pharmacology, Fungi growth & development, Humans, Microbial Sensitivity Tests, Temperature, Virulence Factors analysis, Fungi isolation & purification, Fungi pathogenicity, Soil Microbiology
- Abstract
We assessed the diversity of cultivable fungi in the ornithogenic soil nests of bird species like Phalacrocorax atriceps, Macronectes giganteus, Pygoscelis antarcticus, and Pygoscelis papua in the Antarctic islands. From 481 fungi isolated at 15 °C, only 50 displayed growth at 37 °C, and were identified as 14 species of 15 genera. Aspergillus fumigatus, Penicillium chrysogenum, and Rhodotorula mucilaginosa were the most abundant species obtained. Fifty taxa grew at 40 °C; displayed haemolytic and phospholipase activities; produced tiny spores, capsule, and melanin; showed growth at different pH; and showed resistance to amphotericin B. Interestingly, the minimum inhibitory concentration of amphotericin B increased by 5-10 fold for some A. fumigatus isolates after phagocytosis by amoeba. Our results show relations among fungal community compositions present in Antarctic ornithogenic soil and their pathogenic risk to humans in vitro. As the Antarctica Peninsula is a major region of the planet affected by global climate changes, our results, though preliminary, raise concerns about the dispersal of potential pathogenic microbes present in Antarctic substrates by wild birds, which can fly great distances and spread potential pathogens mainly to South America and Oceania., (Copyright © 2017 British Mycological Society. All rights reserved.)
- Published
- 2017
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15. Taxonomy, phylogeny and ecology of cultivable fungi present in seawater gradients across the Northern Antarctica Peninsula.
- Author
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Gonçalves VN, Vitoreli GA, de Menezes GCA, Mendes CRB, Secchi ER, Rosa CA, and Rosa LH
- Subjects
- Acclimatization, Antarctic Regions, Fungi classification, Fungi genetics, Extreme Cold, Mycobiome, Phylogeny, Seawater microbiology
- Abstract
Thirty-six seawater samples collected at different depths of the Gerlache and Bransfield Straits in the Northern Antarctic Peninsula were analyzed, and the average of the total fungal counts ranged from 0.3 to >300 colony forming units per liter (CFU/L) in density. The fungal were purified and identified as 15 taxa belonged to the genera Acremonium, Aspergillus, Cladosporium, Cystobasidium, Exophiala, Glaciozyma, Graphium, Lecanicillium, Metschnikowia, Penicillium, Purpureocillium and Simplicillium. Penicillium chrysogenum, Cladosporium sphaerospermum, and Graphium rubrum were found at high densities in at least two different sites and depths. Our results show at the first time that in the seawater of Antarctic Ocean occur diverse fungal assemblages despite extreme conditions, which suggests the presence of a complex aquatic fungi food web, including species reported as barophiles, symbionts, weak and strong saprobes, parasites and pathogens, as well as those found in the polluted environments of the world. Additionally, some taxa were found in different sites, suggesting that the underwater current might contribute to fungal (and microbial) dispersal across the Antarctic Ocean, and nearby areas such as South America and Australia.
- Published
- 2017
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16. Antimycobacterial and antimalarial activities of endophytic fungi associated with the ancient and narrowly endemic neotropical plant Vellozia gigantea from Brazil.
- Author
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Ferreira MC, Cantrell CL, Wedge DE, Gonçalves VN, Jacob MR, Khan S, Rosa CA, and Rosa LH
- Subjects
- Anti-Bacterial Agents isolation & purification, Antifungal Agents isolation & purification, Antimalarials isolation & purification, Biological Assay, Candida drug effects, Gram-Negative Bacteria drug effects, Gram-Positive Bacteria drug effects, Magnoliopsida classification, Microbial Sensitivity Tests, Mitosporic Fungi drug effects, Plasmodium drug effects, Tropical Climate, Anti-Bacterial Agents pharmacology, Antifungal Agents pharmacology, Antimalarials pharmacology, Endophytes chemistry, Magnoliopsida microbiology
- Abstract
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.
- Published
- 2017
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17. Antarctic rocks from continental Antarctica as source of potential human opportunistic fungi.
- Author
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Gonçalves VN, Oliveira FS, Carvalho CR, Schaefer CEGR, Rosa CA, and Rosa LH
- Subjects
- Acremonium isolation & purification, Animals, Antarctic Regions, Blood Cells microbiology, Byssochlamys isolation & purification, Cladosporium isolation & purification, Cold Temperature, Penicillium isolation & purification, Phylogeny, Rhodotorula isolation & purification, Sheep, Spores cytology, Extreme Environments, Geologic Sediments microbiology, Hemolysis, Mycobiome
- Abstract
We assessed the diversity of culturable fungi associated with rocks of continental Antarctica to evaluate their physiological opportunistic virulence potential in vitro. The seventy fungal isolates obtained were identified as nine species of Acremonium, Byssochlamys, Cladosporium, Debaryomyces, Penicillium, and Rhodotorula. Acremonium sp., D. hansenii, P. chrysogenum, P. citrinum, P. tardochrysogenum, and R. mucilaginosa were able to grow at 37 °C; in addition, B. spectabilis displayed a high level of growth at 37 and 45 °C. Thirty-one isolates of P. chrysogenum, P. citrinum, and P. tardochrysogenum were able to produce partial haemolysis on blood agar at 37 °C. Acremonium sp., P. citrinum, and P. tardochrysogenum showed spore sizes ranging from 2.81 to 5.13 µm diameters at 37 °C. Of these, P. chrysogenum and P. tardochrysogenum displayed macro- and micro morphological polymorphism. Our results suggest that rocks of the ultra-extreme cold and dry environment of Antarctica harbour cryptic fungi phylogenetically close to opportunistic pathogenic and mycotoxigenic taxa with physiologic virulence characteristics in vitro.
- Published
- 2017
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18. Antarctomyces pellizariae sp. nov., a new, endemic, blue, snow resident psychrophilic ascomycete fungus from Antarctica.
- Author
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de Menezes GC, Godinho VM, Porto BA, Gonçalves VN, and Rosa LH
- Subjects
- Antarctic Regions, Climate Change, DNA, Fungal genetics, Ascomycota classification, Ascomycota genetics, Ascomycota growth & development, Phylogeny
- Abstract
In the present study, we have identified and characterised a new snow resident ascomycete blue stain fungus from Antarctica named Antarctomyces pellizariae sp. nov. Menezes, Godinho, Porto, Gonçalves and Rosa, using polyphasic taxonomy techniques. This fungal species was recovered from the seasonal snow of the Antarctic Peninsula. Antarctomyces pellizariae displayed different macro- and micromorphology when compared with A. psychrotrophicus Stchigel and Guarro, the only other Antarctomyces species reported until date. Antarctomyces pellizariae showed psychrophilic behavior and very low growth rate at 22-25 °C, quite different from A. psychrotrophicus that has a higher growth rate at mesophilic temperatures. In addition, micromorphological characteristics and the analysis of the nuclear rDNA internal transcribed spacer, β-tubulin, and RNA polymerase II regions revealed that A. pellizariae is a new species that is related to A. psychrotrophicus and Thelebolus species. Since the Antarctic Peninsula is reported to be one of the main regions of the earth experiencing the effects of global change in climate, species, such as A. pellizariae, might provide information about these effects on the endemic Antarctic biota. In addition, A. pellizariae displayed psychrophilic behavior and might be a source of interesting anti-freeze compounds that might prove useful in biotechnological processes.
- Published
- 2017
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19. Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds.
- Author
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Mendes G, Gonçalves VN, Souza-Fagundes EM, Kohlhoff M, Rosa CA, Zani CL, Cota BB, Rosa LH, and Johann S
- Subjects
- Animals, Cell Survival drug effects, Chlorocebus aethiops, Chromatography, Reverse-Phase, Cytochalasins analysis, Mass Spectrometry, Methylene Chloride, Microbial Sensitivity Tests, Phylogeny, Sequence Analysis, DNA, Solid Phase Extraction, Vero Cells drug effects, Antifungal Agents pharmacology, Aspergillus chemistry, DNA, Fungal isolation & purification, Desert Climate, Paracoccidioides drug effects
- Abstract
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.
- Published
- 2016
- Full Text
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20. Fungi associated with rocks of the Atacama Desert: taxonomy, distribution, diversity, ecology and bioprospection for bioactive compounds.
- Author
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Gonçalves VN, Cantrell CL, Wedge DE, Ferreira MC, Soares MA, Jacob MR, Oliveira FS, Galante D, Rodrigues F, Alves TM, Zani CL, Junior PA, Murta S, Romanha AJ, Barbosa EC, Kroon EG, Oliveira JG, Gomez-Silva B, Galetovic A, Rosa CA, and Rosa LH
- Subjects
- Ascomycota classification, Ascomycota genetics, Ascomycota isolation & purification, Chile, Cladosporium classification, Cladosporium genetics, Cladosporium isolation & purification, Desert Climate, Ecology, Ecosystem, Molecular Sequence Data, Penicillium classification, Penicillium genetics, Penicillium isolation & purification, Ascomycota metabolism, Cladosporium metabolism, Cryptococcus neoformans drug effects, Geologic Sediments microbiology, Methicillin-Resistant Staphylococcus aureus drug effects, Penicillium metabolism
- Abstract
This study assessed the diversity of cultivable rock-associated fungi from Atacama Desert. A total of 81 fungal isolates obtained were identified as 29 Ascomycota taxa by sequencing different regions of DNA. Cladosporium halotolerans, Penicillium chrysogenum and Penicillium cf. citrinum were the most frequent species, which occur at least in four different altitudes. The diversity and similarity indices ranged in the fungal communities across the latitudinal gradient. The Fisher-α index displayed the higher values for the fungal communities obtained from the siltstone and fine matrix of pyroclastic rocks with finer grain size, which are more degraded. A total of 23 fungal extracts displayed activity against the different targets screened. The extract of P. chrysogenum afforded the compounds α-linolenic acid and ergosterol endoperoxide, which were active against Cryptococcus neoformans and methicillin-resistance Staphylococcus aureus respectively. Our study represents the first report of a new habitat of fungi associated with rocks of the Atacama Desert and indicated the presence of interesting fungal community, including species related with saprobes, parasite/pathogen and mycotoxigenic taxa. The geological characteristics of the rocks, associated with the presence of rich resident/resilient fungal communities suggests that the rocks may provide a favourable microenvironment fungal colonization, survival and dispersal in extreme conditions., (© 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.)
- Published
- 2016
- Full Text
- View/download PDF
21. Diversity and bioprospection of fungal community present in oligotrophic soil of continental Antarctica.
- Author
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Godinho VM, Gonçalves VN, Santiago IF, Figueredo HM, Vitoreli GA, Schaefer CE, Barbosa EC, Oliveira JG, Alves TM, Zani CL, Junior PA, Murta SM, Romanha AJ, Kroon EG, Cantrell CL, Wedge DE, Duke SO, Ali A, Rosa CA, and Rosa LH
- Subjects
- Aedes drug effects, Animals, Antarctic Regions, Anti-Infective Agents isolation & purification, Anti-Infective Agents toxicity, Biological Products isolation & purification, Biological Products toxicity, Cytotoxins isolation & purification, Cytotoxins toxicity, Fungi chemistry, Fungi classification, Humans, Insecticides isolation & purification, Insecticides toxicity, Lactuca drug effects, MCF-7 Cells, Bioprospecting, Extreme Cold, Fungi isolation & purification, Microbiota, Soil Microbiology
- Abstract
We surveyed the diversity and capability of producing bioactive compounds from a cultivable fungal community isolated from 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 fungal community showed low diversity and richness, and high dominance indices. The extracts of Aspergillus sydowii, Penicillium allii-sativi, Penicillium brevicompactum, Penicillium chrysogenum and Penicillium rubens possess antiviral, antibacterial, antifungal, antitumoral, herbicidal and antiprotozoal activities. Bioactive extracts were examined using (1)H NMR spectroscopy and detected the presence of secondary metabolites with 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. 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.
- Published
- 2015
- Full Text
- View/download PDF
22. Diversity and distribution of fungal communities in lakes of Antarctica.
- Author
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Gonçalves VN, Vaz AB, Rosa CA, and Rosa LH
- Subjects
- Antarctic Regions, DNA, Fungal genetics, DNA, Ribosomal Spacer genetics, Fungi genetics, Fungi isolation & purification, Lakes chemistry, Biodiversity, Fungi classification, Lakes microbiology, Phylogeny
- Abstract
This study assessed the diversity and distribution of filamentous fungi obtained from water sampled from six lakes in the Antarctic Peninsula. One hundred and twenty-eight fungal isolates were purified and identified by analysis of nuclear rDNA ITS region sequences as belonging to 31 fungal different operational taxonomic units (OTUs). The most frequently isolated fungi were Geomyces pannorum and Mortierella sp.; these species occurred in six and three of the lakes sampled, respectively, and displayed the highest total colony-forming unit per L. Different species that have not been found to these lakes and/or had adapted to cold conditions were found. In general, the fungal community displayed low richness and high dominance indices. The species Cadophora cf. luteo-olivacea, Cadophora malorum, Davidiella tassiana, G. pannorum, Mortierella cf. alpina and Thelebolus cf. microsporus that were found in the lakes in question were also previously found in other cold ecosystems, such as Arctic, temperate and Alpine regions. The results of this study suggest the presence of an interesting aquatic fungal web, including symbionts, weak and strong saprophytes and parasite/pathogen fungal species. This aquatic web fungal may be a useful community model for further ecological and evolutionary studies of extreme habitats., (© 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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23. Leishmanicidal, trypanocidal, and cytotoxic activities of endophytic fungi associated with bioactive plants in Brazil.
- Author
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Rosa LH, Gonçalves VN, Caligiorne RB, Alves TM, Rabello A, Sales PA, Romanha AJ, Sobral ME, Rosa CA, and Zani CL
- Abstract
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.
- Published
- 2010
- Full Text
- View/download PDF
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