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Catanzaro I, Gerrits R, Feldmann I, Gorbushina AA, Onofri S, Schumacher J. Deletion of the polyketide synthase-encoding gene pks1 prevents melanization in the extremophilic fungus Cryomyces antarcticus. IUBMB Life 2024. [PMID: 39011777 DOI: 10.1002/iub.2895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/15/2024] [Indexed: 07/17/2024]
Abstract
Cryomyces antarcticus, a melanized cryptoendolithic fungus endemic to Antarctica, can tolerate environmental conditions as severe as those in space. Particularly, its ability to withstand ionizing radiation has been attributed to the presence of thick and highly melanized cell walls, which-according to a previous investigation-may contain both 1,8-dihydroxynaphthalene (DHN) and L-3,4 dihydroxyphenylalanine (L-DOPA) melanin. The genes putatively involved in the synthesis of DHN melanin were identified in the genome of C. antarcticus. Most important is capks1 encoding a non-reducing polyketide synthase (PKS) and being the ortholog of the functionally characterized kppks1 from the rock-inhabiting fungus Knufia petricola. The co-expression of CaPKS1 or KpPKS1 with a 4'-phosphopantetheinyl transferase in Saccharomyces cerevisiae resulted in the formation of a yellowish pigment, suggesting that CaPKS1 is the enzyme providing the precursor for DHN melanin. To dissect the composition and function of the melanin layer in the outer cell wall of C. antarcticus, non-melanized mutants were generated by CRISPR/Cas9-mediated genome editing. Notwithstanding its slow growth (up to months), three independent non-melanized Δcapks1 mutants were obtained. The mutants exhibited growth similar to the wild type and a light pinkish pigmentation, which is presumably due to carotenoids. Interestingly, visible light had an adverse effect on growth of both melanized wild-type and non-melanized Δcapks1 strains. Further evidence that light can pass the melanized cell walls derives from a mutant expressing a H2B-GFP fusion protein, which can be detected by fluorescence microscopy. In conclusion, the study reports on the first genetic manipulation of C. antarcticus, resulting in non-melanized mutants and demonstrating that the melanin is rather of the DHN type. These mutants will allow to elucidate the relevance of melanization for surviving extreme conditions found in the natural habitat as well as in space.
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Affiliation(s)
- Ilaria Catanzaro
- Department Materials and the Environment, Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
- Department of Ecological and Biological Sciences (DEB), Università degli Studi della Tuscia, Viterbo, Italy
| | - Ruben Gerrits
- Department Materials and the Environment, Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | - Ines Feldmann
- Department Materials and the Environment, Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | - Anna A Gorbushina
- Department Materials and the Environment, Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Silvano Onofri
- Department of Ecological and Biological Sciences (DEB), Università degli Studi della Tuscia, Viterbo, Italy
| | - Julia Schumacher
- Department Materials and the Environment, Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
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2
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Cassaro A, Pacelli C, Baqué M, Cavalazzi B, Gasparotto G, Saladino R, Botta L, Böttger U, Rabbow E, de Vera JP, Onofri S. Investigation of fungal biomolecules after Low Earth Orbit exposure: a testbed for the next Moon missions. Environ Microbiol 2022; 24:2938-2950. [PMID: 35437941 PMCID: PMC9540993 DOI: 10.1111/1462-2920.15995] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 03/31/2022] [Accepted: 04/02/2022] [Indexed: 11/28/2022]
Abstract
The Moon is characterized by extremely harsh conditions due to ultraviolet irradiation, wide temperature extremes, vacuum resulting from the absence of an atmosphere and high ionizing radiation. Therefore, its surface may provide a unique platform to investigate the effects of such conditions. For lunar exploration with the Lunar Gateway platform, exposure experiments in Low Earth Orbit are useful testbeds to prepare for lunar space experiments and to understand how and if potential biomarkers are influenced by extra‐terrestrial conditions. During the BIOMEX (BIOlogy and Mars EXperiment) project, dried colonies of the fungus Cryomyces antarcticus grown on Lunar Regolith Analogue (LRA) were exposed to space conditions for 16 months aboard the EXPOSE‐R2 payload outside the International Space Station. In this study, we investigated the stability/degradation of fungal biomarkers in LRA after exposure to (i) simulated space and (ii) real space conditions, using Raman spectroscopy, gas chromatography–mass spectrometry and DNA amplification. The results demonstrated that fungal biomarkers were detectable after 16 months of real space exposure. This work will contribute to the interpretation of data from future biological experiments in the Cislunar orbit with the Lunar Gateway platform and/or on the lunar surface, in preparation for the next step of human exploration.
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Affiliation(s)
- Alessia Cassaro
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, Viterbo, 01100, Italy
| | - Claudia Pacelli
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, Viterbo, 01100, Italy.,Human Spaceflight and Scientific Research Unit, Italian Space Agency, via del Politecnico, Rome, 00133, Italy
| | - Mickael Baqué
- German Aerospace Center (DLR), Institute of Planetary Research, Planetary Laboratories Department, Rutherfordstraße 2, Berlin, Germany
| | - Barbara Cavalazzi
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Zamboni 67, Bologna, 40126, Italy.,Department of Geology, University of Johannesburg, Auckland Park, Johannesburg, 2006, South Africa.,Le Studium Loire Valley Institute for Advanced Studies, Rue Dupanloup 1, Orléans, France
| | - Giorgio Gasparotto
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Zamboni 67, Bologna, 40126, Italy
| | - Raffaele Saladino
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, Viterbo, 01100, Italy
| | - Lorenzo Botta
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, Viterbo, 01100, Italy
| | - Ute Böttger
- German Aerospace Center (DLR), Institute of Optical Sensor Systems, Rutherfordstraße 2, Berlin, Germany
| | - Elke Rabbow
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology, Linder Höhe, Cologne, 51147, Germany
| | - Jean-Pierre de Vera
- Space Operations and Astronaut Training, MUSC, German Aerospace Center (DLR), Linder Höhe, Cologne, 51147, Germany
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, Viterbo, 01100, Italy
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3
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Liu B, Fu R, Wu B, Liu X, Xiang M. Rock-inhabiting fungi: terminology, diversity, evolution and adaptation mechanisms. Mycology 2022; 13:1-31. [PMID: 35186410 PMCID: PMC8856086 DOI: 10.1080/21501203.2021.2002452] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Rock-inhabiting fungi (RIF) constitute an ecological group associated with terrestrial rocks. This association is generally restricted to the persistent colonisation of rocks and peculiar morphological features based on melanisation and slow growth, which endow RIF with significance in eukaryotic biology, special status in ecology, and exotic potential in biotechnology. There is a need to achieve a better understanding of the hidden biodiversity, antistress biology, origin and convergent evolution of RIF, which will facilitate cultural relic preservation, exploitation of the biogeochemical cycle of rock elements and biotechnology applications. This review focuses on summarising the current knowledge of rock-inhabiting fungi, with particular reference to terminology, biodiversity and geographic distribution, origin and evolution, and stress adaptation mechanisms. We especially teased out the definition through summing up the terms related to rock-inhabting fungi, and also provided a checklist of rock-inhabiting fungal taxa recorded following updated classification schemes.
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Affiliation(s)
- Bingjie Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Rong Fu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Bing Wu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xingzhong Liu
- Department of Microbiology, College of Life Science, Nankai University, Tianjin, China
| | - Meichun Xiang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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4
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Understanding the way eumelanin works: A unique example of properties and skills driven by molecular heterogeneity. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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5
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Kreusch MG, Duarte RTD. Photoprotective compounds and radioresistance in pigmented and non-pigmented yeasts. Appl Microbiol Biotechnol 2021; 105:3521-3532. [PMID: 33900423 DOI: 10.1007/s00253-021-11271-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 03/28/2021] [Accepted: 04/05/2021] [Indexed: 10/21/2022]
Abstract
Ultraviolet radiation, continuously reaching our planet's surface, is a type of electromagnetic energy within the wavelength range of 10 to 400 nm. Despite essential for all life on Earth, ultraviolet radiation may have severe adverse cellular effects, including DNA dimerization and production of reactive oxygen species. Radioresistant microorganisms can survive under high doses of ultraviolet radiation, enduring the direct and indirect effects on nucleic acids and other biomolecules. The synthesis and accumulation of photoprotective compounds are among the main strategies employed by radioresistant yeast species to bear the harmful effects of ultraviolet radiation. A correlation between pigments and resistance to ultraviolet radiation has been widely recognized in these microorganisms; however, there is still some debate on this topic, with non-pigmented strains sometimes being more resistant than their pigmented counterparts. In this review, we explore the role of photoprotective compounds-specifically, melanin, carotenoids, and mycosporines-and compare the differences found in resistance between pigmented and non-pigmented yeasts. We also discuss the biotechnological potential of these photoprotective compounds, with special emphasis on those produced by non-pigmented yeast strains, such as phytoene and phytofluene. The use of "-omics" approaches should further unveil the radioresistance mechanisms of non-pigmented yeasts, opening new opportunities for both research and commercial applications. KEY POINTS: • Updated knowledge on photoprotective compounds from radioresistant yeasts. • Differences on radioresistance between pigmented and non-pigmented yeasts. • Future prospects over the study of non-pigmented photoprotective compounds.
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Affiliation(s)
- Marianne Gabi Kreusch
- Laboratory of Molecular Ecology and Extremophiles, Department of Microbiology, Immunology and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Rubens Tadeu Delgado Duarte
- Laboratory of Molecular Ecology and Extremophiles, Department of Microbiology, Immunology and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
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6
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Tesei D, Chiang AJ, Kalkum M, Stajich JE, Mohan GBM, Sterflinger K, Venkateswaran K. Effects of Simulated Microgravity on the Proteome and Secretome of the Polyextremotolerant Black Fungus Knufia chersonesos. Front Genet 2021; 12:638708. [PMID: 33815472 PMCID: PMC8012687 DOI: 10.3389/fgene.2021.638708] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/19/2021] [Indexed: 11/13/2022] Open
Abstract
Black fungi are a group of melanotic microfungi characterized by remarkable polyextremotolerance. Due to a broad ecological plasticity and adaptations at the cellular level, it is predicted that they may survive in a variety of extreme environments, including harsh niches on Earth and Mars, and in outer space. However, the molecular mechanisms aiding survival, especially in space, are yet to be fully elucidated. Based on these premises, the rock-inhabiting black fungus Knufia chersonesos (Wt) and its non-melanized mutant (Mut) were exposed to simulated microgravity-one of the prevalent features characterizing space conditions-by growing the cultures in high-aspect-ratio vessels (HARVs). Qualitative and quantitative proteomic analyses were performed on the mycelia and supernatant of culture medium (secretome) to assess alterations in cell physiology in response to low-shear simulated microgravity (LSSMG) and to ultimately evaluate the role of cell-wall melanization in stress survival. Differential expression was observed for proteins involved in carbohydrate and lipid metabolic processes, transport, and ribosome biogenesis and translation via ribosomal translational machinery. However, no evidence of significant activation of stress components or starvation response was detected, except for the scytalone dehydratase, enzyme involved in the synthesis of dihydroxynaphthalene (DNH) melanin, which was found to be upregulated in the secretome of the wild type and downregulated in the mutant. Differences in protein modulation were observed between K. chersonesos Wt and Mut, with several proteins being downregulated under LSSMG in the Mut when compared to the Wt. Lastly, no major morphological alterations were observed following exposure to LSSMG. Similarly, the strains' survivability was not negatively affected. This study is the first to characterize the response to simulated microgravity in black fungi, which might have implications on future astrobiological missions.
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Affiliation(s)
- Donatella Tesei
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
| | - Abby J. Chiang
- Department of Molecular Imaging and Therapy, Beckman Research Institute of City of Hope, Duarte, CA, United States
| | - Markus Kalkum
- Department of Molecular Imaging and Therapy, Beckman Research Institute of City of Hope, Duarte, CA, United States
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Ganesh Babu Malli Mohan
- Department of Biotechnology, Centre for Research and Infectious Diseases, SASTRA Deemed University, Thanjavur, India
| | - Katja Sterflinger
- Institute for Natural Sciences and Technology in the Arts, Academy of Fine Arts Vienna, Vienna, Austria
| | - Kasthuri Venkateswaran
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
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7
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Coleine C, Stajich JE, de Los Ríos A, Selbmann L. Beyond the extremes: Rocks as ultimate refuge for fungi in drylands. Mycologia 2020; 113:108-133. [PMID: 33232202 DOI: 10.1080/00275514.2020.1816761] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In an era of rapid climate change and expansion of desertification, the extremely harsh conditions of drylands are a true challenge for microbial life. Under drought conditions, where most life forms cannot survive, rocks represent the main refuge for life. Indeed, the endolithic habitat provides thermal buffering, physical stability, and protection against incident ultraviolet (UV) radiation and solar radiation and, to some extent, ensures water retention to microorganisms. The study of these highly specialized extreme-tolerant and extremophiles may provide tools for understanding microbial interactions and processes that allow them to keep their metabolic machinery active under conditions of dryness and oligotrophy that are typically incompatible with active life, up to the dry limits for life. Despite lithobiontic communities being studied all over the world, a comprehensive understanding of their ecology, evolution, and adaptation is still nascent. Herein, we survey the fungal component of these microbial ecosystems. We first provide an overview of the main defined groups (i.e., lichen-forming fungi, black fungi, and yeasts) of the most known and studied Antarctic endolithic communities that are almost the only life forms ensuring ecosystem functionality in the ice-free areas of the continent. For each group, we discuss their main traits and their diversity. Then, we focus on the fungal taxonomy and ecology of other worldwide endolithic communities. Finally, we highlight the utmost importance of a global rock survey in order to have a comprehensive view of the diversity, distribution, and functionality of these fungi in drylands, to obtain tools in desert area management, and as early alarm systems to climate change.
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Affiliation(s)
- Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia , Largo dell'Università snc, 01100, Viterbo, Italy
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, 900 University Ave , Riverside, California 92521
| | - Asunción de Los Ríos
- Department of Biogeochemistry and Microbial Ecology, Museo Nacional de Ciencias Naturales, Spanish National Resource Council, Madrid, Spain
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia , Largo dell'Università snc, 01100, Viterbo, Italy.,Italian National Antarctic Museum, Mycological Section, Genoa, Italy
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8
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Coleine C, Masonjones S, Sterflinger K, Onofri S, Selbmann L, Stajich JE. Peculiar genomic traits in the stress-adapted cryptoendolithic Antarctic fungus Friedmanniomyces endolithicus. Fungal Biol 2020; 124:458-467. [PMID: 32389308 DOI: 10.1016/j.funbio.2020.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/15/2020] [Accepted: 01/19/2020] [Indexed: 11/28/2022]
Abstract
Friedmanniomyces endolithicus is a highly melanized fungus endemic to the Antarctic, occurring exclusively in endolithic communities of the ice-free areas of the Victoria Land, including the McMurdo Dry Valleys, the coldest and most hyper-arid desert on Earth and accounted as the Martian analog on our planet. F. endolithicus is highly successful in these inhospitable environments, the most widespread and commonly isolated species from these peculiar niches, indicating a high degree of adaptation. The nature of its extremo tolerance has not been previously studied. To investigate this, we sequenced genome of F. endolithicus CCFEE 5311 to explore gene content and genomic patterns that could be attributed to its specialization. The predicted functional potential of the genes was assigned by similarity to InterPro and CAZy domains. The genome was compared to phylogenetically close relatives which are also melanized fungi occurring in extreme environments including Friedmanniomyces simplex, Baudoinia panamericana, Acidomyces acidophilus, Hortaea thailandica and Hortaea werneckii. We tested if shared genomic traits existed among these species and hyper-extremotolerant fungus F. endolithicus. We found that some characters for stress tolerance such as meristematic growth and cold tolerance are enriched in F. endolithicus that may be triggered by the exposure to Antarctic prohibitive conditions.
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Affiliation(s)
- Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy.
| | - Sawyer Masonjones
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, CA, USA.
| | - Katja Sterflinger
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria.
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy.
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy; Italian Antarctic National Museum (MNA), Mycological Section, Genoa, Italy.
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, CA, USA.
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9
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Coleine C, Selbmann L, Masonjones S, Onofri S, Zucconi L, Stajich JE. Draft Genome Sequence of an Antarctic Isolate of the Black Yeast Fungus Exophiala mesophila. Microbiol Resour Announc 2019; 8:e00142-19. [PMID: 31072892 PMCID: PMC6509517 DOI: 10.1128/mra.00142-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 04/15/2019] [Indexed: 11/22/2022] Open
Abstract
A 30.43-Mb draft genome sequence with 10,355 predicted protein-coding genes was produced for the ascomycete fungus Exophiala mesophila strain CCFEE 6314, a black yeast isolated from Antarctic cryptoendolithic communities. The sequence will be of importance for identifying differences among extremophiles and mesophiles and cataloguing the global population diversity of this organism.
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Affiliation(s)
- Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
- Mycological Section, Italian National Antarctic Museum (MNA), Genoa, Italy
| | - Sawyer Masonjones
- Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, California, USA
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, California, USA
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10
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Onofri S, Selbmann L, Pacelli C, Zucconi L, Rabbow E, de Vera JP. Survival, DNA, and Ultrastructural Integrity of a Cryptoendolithic Antarctic Fungus in Mars and Lunar Rock Analogs Exposed Outside the International Space Station. ASTROBIOLOGY 2019; 19:170-182. [PMID: 30376361 DOI: 10.1089/ast.2017.1728] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The search for life beyond Earth involves investigation into the responses of model organisms to the deleterious effects of space. In the frame of the BIOlogy and Mars Experiment, as part of the European Space Agency (ESA) space mission EXPOSE-R2 in low Earth orbit (LEO), dried colonies of the Antarctic cryptoendolithic black fungus Cryomyces antarcticus CCFEE 515 were grown on martian and lunar analog regolith pellets, and exposed for 16 months to LEO space and simulated Mars-like conditions on the International Space Station. The results demonstrate that C. antarcticus was able to tolerate the combined stress of different extraterrestrial substrates, space, and simulated Mars-like conditions in terms of survival, DNA, and ultrastructural stability. Results offer insights into the habitability of Mars for future exploration missions on Mars. Implications for the detection of biosignatures in extraterrestrial conditions and planetary protection are discussed.
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Affiliation(s)
- Silvano Onofri
- 1 Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Laura Selbmann
- 1 Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
- 2 Section of Mycology, Italian National Antarctic Museum, Viterbo, Italy
| | - Claudia Pacelli
- 1 Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Laura Zucconi
- 1 Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Elke Rabbow
- 3 Institute of Aerospace Medicine, German Aerospace Centre, Köln, Germany
| | - Jean-Pierre de Vera
- 4 Astrobiological Laboratories, Institute of Planetary Research, Management and Infrastructure, German Aerospace Center (DLR) Berlin, Berlin, Germany
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11
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Huwe B, Fiedler A, Moritz S, Rabbow E, de Vera JP, Joshi J. Mosses in Low Earth Orbit: Implications for the Limits of Life and the Habitability of Mars. ASTROBIOLOGY 2019; 19:221-232. [PMID: 30742499 DOI: 10.1089/ast.2018.1889] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
As a part of the European Space Agency mission "EXPOSE-R2" on the International Space Station (ISS), the BIOMEX (Biology and Mars Experiment) experiment investigates the habitability of Mars and the limits of life. In preparation for the mission, experimental verification tests and scientific verification tests simulating different combinations of abiotic space- and Mars-like conditions were performed to analyze the resistance of a range of model organisms. The simulated abiotic space- and Mars-stressors were extreme temperatures, vacuum, and Mars-like surface ultraviolet (UV) irradiation in different atmospheres. We present for the first time simulated space exposure data of mosses using plantlets of the bryophyte genus Grimmia, which is adapted to high altitudinal extreme abiotic conditions at the Swiss Alps. Our preflight tests showed that severe UVR200-400nm irradiation with the maximal dose of 5 and 6.8 × 105 kJ·m-2, respectively, was the only stressor with a negative impact on the vitality with a 37% (terrestrial atmosphere) or 36% reduction (space- and Mars-like atmospheres) in photosynthetic activity. With every exposure to UVR200-400nm 105 kJ·m-2, the vitality of the bryophytes dropped by 6%. No effect was found, however, by any other stressor. As the mosses were still vital after doses of ultraviolet radiation (UVR) expected during the EXPOSE-R2 mission on ISS, we show that this earliest extant lineage of land plants is highly resistant to extreme abiotic conditions.
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Affiliation(s)
- Björn Huwe
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
| | - Annelie Fiedler
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
| | - Sophie Moritz
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
| | - Elke Rabbow
- 2 Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Jean Pierre de Vera
- 3 Astrobiological Laboratories, Management and Infrastructure, Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
| | - Jasmin Joshi
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
- 4 Institute for Landscape and Open Space, Hochschule für Technik HSR Rapperswil, Rapperswil, Switzerland
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12
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Pacelli C, Selbmann L, Zucconi L, Coleine C, de Vera JP, Rabbow E, Böttger U, Dadachova E, Onofri S. Responses of the Black Fungus Cryomyces antarcticus to Simulated Mars and Space Conditions on Rock Analogs. ASTROBIOLOGY 2019; 19:209-220. [PMID: 30067087 DOI: 10.1089/ast.2016.1631] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The BIOMEX (BIOlogy and Mars Experiment) is part of the European Space Agency (ESA) space mission EXPOSE-R2 in Low-Earth Orbit, devoted to exposing microorganisms for 1.5 years to space and simulated Mars conditions on the International Space Station. In preparing this mission, dried colonies of the Antarctic cryptoendolithic black fungus Cryomyces antarcticus CCFEE 515, grown on martian and lunar analog regolith pellets, were subjected to several ground-based preflight tests, Experiment Verification Tests, and Science Verification Tests (SVTs) that were performed to verify (i) the resistance of our model organism to space stressors when grown on extraterrestrial rock analogs and (ii) the possibility of detecting biomolecules as potential biosignatures. Here, the results of the SVTs, the last set of experiments, which were performed in ultraviolet radiation combined with simulated space vacuum or simulated martian conditions, are reported. The results demonstrate that C. antarcticus was able to tolerate the conditions of the SVT experiment, regardless of the substratum in which it was grown. DNA maintained high integrity after treatments and was confirmed as a possible biosignature; melanin, which was chosen to be a target for biosignature detection, was unambiguously detected by Raman spectroscopy.
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Affiliation(s)
- Claudia Pacelli
- 1 Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
| | - Laura Selbmann
- 1 Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
- 2 Section of Mycology, Italian Antarctic National Museum (MNA), Genoa, Italy
| | - Laura Zucconi
- 1 Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
| | - Claudia Coleine
- 1 Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
| | - Jean-Pierre de Vera
- 3 Institute of Planetary Research, German Aerospace Center (DLR) Berlin, Berlin, Germany
| | - Elke Rabbow
- 4 German Aerospace Centre, Institute of Aerospace Medicine (DLR), Köln, Germany
| | - Ute Böttger
- 5 Institute of Optical Sensor Systems, German Aerospace Center (DLR) Berlin, Berlin, Germany
| | - Ekaterina Dadachova
- 6 College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
| | - Silvano Onofri
- 1 Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
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13
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A Systematic Way to Life Detection: Combining Field, Lab and Space Research in Low Earth Orbit. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/978-3-319-96175-0_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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14
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Coleine C, Stajich JE, Zucconi L, Onofri S, Pombubpa N, Egidi E, Franks A, Buzzini P, Selbmann L. Antarctic Cryptoendolithic Fungal Communities Are Highly Adapted and Dominated by Lecanoromycetes and Dothideomycetes. Front Microbiol 2018; 9:1392. [PMID: 30008702 PMCID: PMC6033990 DOI: 10.3389/fmicb.2018.01392] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/06/2018] [Indexed: 12/14/2022] Open
Abstract
Endolithic growth is one of the most spectacular microbial adaptations to extreme environmental constraints and the predominant life-form in the ice-free areas of Continental Antarctica. Although Antarctic endolithic microbial communities are known to host among the most resistant and extreme-adapted organisms, our knowledge on microbial diversity and composition in this peculiar niche is still limited. In this study, we investigated the diversity and structure of the fungal assemblage in the cryptoendolithic communities inhabiting sandstone using a meta-barcoding approach targeting the fungal Internal Transcribed Sequence region 1 (ITS1). Samples were collected from 14 sites in the Victoria Land, along an altitudinal gradient ranging from 1,000 to 3,300 m a.s.l. and from 29 to 96 km distance to coast. Our study revealed a clear dominance of a 'core' group of fungal taxa consistently present across all the samples, mainly composed of lichen-forming and Dothideomycetous fungi. Pareto-Lorenz curves indicated a very high degree of specialization (F0 approximately 95%), suggesting these communities are highly adapted but have limited ability to recover after perturbations. Overall, both fungal community biodiversity and composition did not show any correlation with the considered abiotic parameters, potentially due to strong fluctuations of environmental conditions at local scales.
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Affiliation(s)
- Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Nuttapon Pombubpa
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Eleonora Egidi
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Ashley Franks
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC, Australia
- Centre for Future Landscapes, La Trobe University, Melbourne, VIC, Australia
| | - Pietro Buzzini
- Department of Agricultural, Food and Environmental Sciences, Industrial Yeasts Collection DBVPG, University of Perugia, Perugia, Italy
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
- Section of Mycology, Italian National Antarctic Museum (MNA), Genoa, Italy
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15
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Onofri S, Selbmann L, Pacelli C, de Vera JP, Horneck G, Hallsworth JE, Zucconi L. Integrity of the DNA and Cellular Ultrastructure of Cryptoendolithic Fungi in Space or Mars Conditions: A 1.5-Year Study at the International Space Station. Life (Basel) 2018; 8:E23. [PMID: 29921763 PMCID: PMC6027225 DOI: 10.3390/life8020023] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/10/2018] [Accepted: 06/12/2018] [Indexed: 11/17/2022] Open
Abstract
The black fungi Cryomyces antarcticus and Cryomyces minteri are highly melanized and are resilient to cold, ultra-violet, ionizing radiation and other extreme conditions. These microorganisms were isolated from cryptoendolithic microbial communities in the McMurdo Dry Valleys (Antarctica) and studied in Low Earth Orbit (LEO), using the EXPOSE-E facility on the International Space Station (ISS). Previously, it was demonstrated that C. antarcticus and C. minteri survive the hostile conditions of space (vacuum, temperature fluctuations, and the full spectrum of extraterrestrial solar electromagnetic radiation), as well as Mars conditions that were simulated in space for a 1.5-year period. Here, we qualitatively and quantitatively characterize damage to DNA and cellular ultrastructure in desiccated cells of these two species, within the frame of the same experiment. The DNA and cells of C. antarcticus exhibited a higher resistance than those of C. minteri. This is presumably attributable to the thicker (melanized) cell wall of the former. Generally, DNA was readily detected (by PCR) regardless of exposure conditions or fungal species, but the C. minteri DNA had been more-extensively mutated. We discuss the implications for using DNA, when properly shielded, as a biosignature of recently extinct or extant life.
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Affiliation(s)
- Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, 01100 Viterbo, Italy.
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, 01100 Viterbo, Italy.
- Italian National Antarctic Museum (MNA), Mycological Section, 16166 Genoa, Italy.
| | - Claudia Pacelli
- Department of Ecological and Biological Sciences, University of Tuscia, 01100 Viterbo, Italy.
| | - Jean Pierre de Vera
- German Aerospace Center (DLR) Berlin, Institute of Planetary Research, Rutherfordstreet 2, 12489 Berlin, Germany.
| | - Gerda Horneck
- German Aerospace Centre, Institute of Aerospace Medicine, Linder Hoehe, D 51170 Köln, Germany.
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast BT9 7BL, UK.
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, 01100 Viterbo, Italy.
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16
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de la Torre Noetzel R, Miller AZ, de la Rosa JM, Pacelli C, Onofri S, García Sancho L, Cubero B, Lorek A, Wolter D, de Vera JP. Cellular Responses of the Lichen Circinaria gyrosa in Mars-Like Conditions. Front Microbiol 2018; 9:308. [PMID: 29556220 PMCID: PMC5845166 DOI: 10.3389/fmicb.2018.00308] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 02/09/2018] [Indexed: 11/13/2022] Open
Abstract
Lichens are extremely resistant organisms that colonize harsh climatic areas, some of them defined as "Mars-analog sites." There still remain many unsolved questions as to how lichens survive under such extreme conditions. Several studies have been performed to test the resistance of various lichen species under space and in simulated Mars-like conditions. The results led to the proposal that Circinaria gyrosa (Lecanoromycetes, Ascomycota) is one of the most durable astrobiological model lichens. However, although C. gyrosa has been exposed to Mars-like environmental conditions while in a latent state, it has not been exposed in its physiologically active mode. We hypothesize that the astrobiological test system "Circinaria gyrosa," could be able to be physiologically active and to survive under Mars-like conditions in a simulation chamber, based on previous studies performed at dessicated-dormant stage under simulated Mars-like conditions, that showed a complete recover of the PSII activity (Sánchez et al., 2012). Epifluorescence and confocal laser scanning microscopy (CLSM) showed that living algal cells were more abundant in samples exposed to niche conditions, which simulated the conditions in micro-fissures and micro-caves close to the surface that have limited scattered or time-dependent light exposure, than in samples exposed to full UV radiation. The medulla was not structurally affected, suggesting that the niche exposure conditions did not disturb the lichen thalli structure and morphology as revealed by field emission scanning electron microscopy (FESEM). In addition, changes in the lichen thalli chemical composition were determined by analytical pyrolysis. The chromatograms resulting from analytical pyrolysis at 500°C revealed that lichen samples exposed to niche conditions and full UV radiation consisted primarily of glycosidic compounds, lipids, and sterols, which are typical constituents of the cell walls. However, specific differences could be detected and used as markers of the UV-induced damage to the lichen membranes. Based on its viability responses after rehydration, our study shows that the test lichen survived the 30-day incubation in the Mars chamber particularly under niche conditions. However, the photobiont was not able to photosynthesize under the Mars-like conditions, which indicates that the surface of Mars is not a habitable place for C. gyrosa.
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Affiliation(s)
- Rosa de la Torre Noetzel
- Departamento de Observación de la Tierra, Instituto Nacional de Técnica Aeroespacial, Madrid, Spain
| | - Ana Z Miller
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Sevilla, Spain
| | - José M de la Rosa
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Sevilla, Spain
| | - Claudia Pacelli
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | | | - Beatriz Cubero
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Sevilla, Spain
| | - Andreas Lorek
- German Aerospace Center (DLR) Berlin, Institute of Planetary Research, Berlin, Germany
| | - David Wolter
- German Aerospace Center (DLR) Berlin, Institute of Planetary Research, Berlin, Germany
| | - Jean P de Vera
- German Aerospace Center (DLR) Berlin, Institute of Planetary Research, Berlin, Germany
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17
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Olsson-Francis K, Ramkissoon NK, Price AB, Slade DJ, Macey MC, Pearson VK. The Study of Microbial Survival in Extraterrestrial Environments Using Low Earth Orbit and Ground-Based Experiments. J Microbiol Methods 2018. [DOI: 10.1016/bs.mim.2018.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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18
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Knabe N, Gorbushina AA. Territories of Rock-Inhabiting Fungi: Survival on and Alteration of Solid Air-Exposed Surfaces. J Microbiol Methods 2018. [DOI: 10.1016/bs.mim.2018.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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19
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Selbmann L, Pacelli C, Zucconi L, Dadachova E, Moeller R, de Vera JP, Onofri S. Resistance of an Antarctic cryptoendolithic black fungus to radiation gives new insights of astrobiological relevance. Fungal Biol 2017; 122:546-554. [PMID: 29801799 DOI: 10.1016/j.funbio.2017.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/25/2017] [Accepted: 10/26/2017] [Indexed: 11/18/2022]
Abstract
The Antarctic black meristematic fungus Cryomyces antarcticus CCFEE 515 occurs endolithically in the McMurdo Dry Valleys of Antarctica, one of the best analogue for Mars environment on Earth. To date, this fungus is considered one of the best eukaryotic models for astrobiological studies and has been repeatedly selected for space experiments in the last decade. The obtained results are reviewed here, with special focus on responses to space relevant irradiation, UV radiation, and both sparsely and densely ionizing radiation, which represent the major injuries for a putative space-traveller. The remarkable resistance of this model organism to space stress, its radioresistance in particular, and mechanisms involved, significantly contributed to expanding our concept of limits for life and provided new insights on the origin and evolution of life in planetary systems, habitability, and biosignatures for life detection as well as on human protection during space missions.
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Affiliation(s)
- Laura Selbmann
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy.
| | - Claudia Pacelli
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy.
| | - Laura Zucconi
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy.
| | - Ekaterina Dadachova
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada.
| | - Ralf Moeller
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne (Köln), Germany.
| | - Jean-Pierre de Vera
- German Aerospace Center (DLR), Institute of Planetary Research, Management and Infrastructure, Astrobiological Laboratories, Rutherfordstr. 2, 12489 Berlin, Germany.
| | - Silvano Onofri
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy.
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20
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Pacelli C, Selbmann L, Moeller R, Zucconi L, Fujimori A, Onofri S. Cryptoendolithic Antarctic Black Fungus Cryomyces antarcticus Irradiated with Accelerated Helium Ions: Survival and Metabolic Activity, DNA and Ultrastructural Damage. Front Microbiol 2017; 8:2002. [PMID: 29089932 PMCID: PMC5650992 DOI: 10.3389/fmicb.2017.02002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/28/2017] [Indexed: 11/22/2022] Open
Abstract
Space represents an extremely harmful environment for life and survival of terrestrial organisms. In the last decades, a considerable deal of attention was paid to characterize the effects of spaceflight relevant radiation on various model organisms. The aim of this study was to test the survival capacity of the cryptoendolithic black fungus Cryomyces antarcticus CCFEE 515 to space relevant radiation, to outline its endurance to space conditions. In the frame of an international radiation campaign, dried fungal colonies were irradiated with accelerated Helium ion (150 MeV/n, LET 2.2 keV/μm), up to a final dose of 1,000 Gy, as one of the space-relevant ionizing radiation. Results showed that the fungus maintained high survival and metabolic activity with no detectable DNA and ultrastructural damage, even after the highest dose irradiation. These data give clues on the resistance of life toward space ionizing radiation in general and on the resistance and responses of eukaryotic cells in particular.
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Affiliation(s)
- Claudia Pacelli
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Ralf Moeller
- German Aerospace Center, Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne, Germany
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Akira Fujimori
- National Institute of Radiological Sciences, Research Center for Charged Particle Therapy, Chiba, Japan
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
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21
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Selbmann L, Onofri S, Coleine C, Buzzini P, Canini F, Zucconi L. Effect of environmental parameters on biodiversity of the fungal component in lithic Antarctic communities. Extremophiles 2017; 21:1069-1080. [PMID: 28993960 DOI: 10.1007/s00792-017-0967-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 09/21/2017] [Indexed: 11/29/2022]
Abstract
A wide sampling of rocks, colonized by microbial epi-endolithic communities, was performed along an altitudinal gradient from sea level to 3600 m asl and sea distance from the coast to 100 km inland along the Victoria Land Coast, Antarctica. Seventy-two rock samples of different typology, representative of the entire survey, were selected and studied using denaturing gradient gel electrophoresis to compare variation in fungal diversity according to environmental conditions along this altitudinal and sea distance transect. Lichenized fungi were largely predominant in all the samples studied and the biodiversity was heavily influenced even by minimal local variations. The n-MDS analysis showed that altitude and sea distance affect fungal biodiversity, while sandstone allows the communities to maintain high biodiversity indices. The Pareto-Lorenz curves indicate that all the communities analyzed are highly adapted to extreme conditions but scarcely resilient, so any external perturbation may have irreversible effects on these fragile ecosystems.
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Affiliation(s)
- Laura Selbmann
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy.
| | - Silvano Onofri
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
| | - Claudia Coleine
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
| | - Pietro Buzzini
- Department of Agricultural, Food and Environmental Sciences, Industrial Yeasts Collection DBVPG, University of Perugia, Perugia, Italy
| | - Fabiana Canini
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
| | - Laura Zucconi
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Viterbo, Italy
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22
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Pacelli C, Selbmann L, Zucconi L, Raguse M, Moeller R, Shuryak I, Onofri S. Survival, DNA Integrity, and Ultrastructural Damage in Antarctic Cryptoendolithic Eukaryotic Microorganisms Exposed to Ionizing Radiation. ASTROBIOLOGY 2017; 17:126-135. [PMID: 28151696 PMCID: PMC5314979 DOI: 10.1089/ast.2015.1456] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 09/15/2016] [Indexed: 05/27/2023]
Abstract
Life dispersal between planets, planetary protection, and the search for biosignatures are main topics in astrobiology. Under the umbrella of the STARLIFE project, three Antarctic endolithic microorganisms, the melanized fungus Cryomyces antarcticus CCFEE 515, a hyaline strain of Umbilicaria sp. (CCFEE 6113, lichenized fungus), and a Stichococcus sp. strain (C45A, green alga), were exposed to high doses of space-relevant gamma radiation (60Co), up to 117.07 kGy. After irradiation survival, DNA integrity and ultrastructural damage were tested. The first was assessed by clonogenic test; viability and dose responses were reasonably described by the linear-quadratic formalism. DNA integrity was evaluated by PCR, and ultrastructural damage was observed by transmission electron microscopy. The most resistant among the tested organisms was C. antarcticus both in terms of colony formation and DNA preservation. Besides, results clearly demonstrate that DNA was well detectable in all the tested organisms even when microorganisms were dead. This high resistance provides support for the use of DNA as a possible biosignature during the next exploration campaigns. Implication in planetary protection and contamination during long-term space travel are put forward. Key Words: Biosignatures-Ionizing radiation-DNA integrity-Eukaryotic microorganisms-Fingerprinting-Mars exploration. Astrobiology 17, 126-135.
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Affiliation(s)
- Claudia Pacelli
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Marina Raguse
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Ralf Moeller
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Igor Shuryak
- Center for Radiological Research, Columbia University, New York, USA
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
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