Silvano Onofri

Silvano Onofri
Tuscia University | Tuscia · Department of Biological and Ecological Sciences DEB

About

178
Publications
65,998
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5,300
Citations
Citations since 2017
73 Research Items
3557 Citations
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20172018201920202021202220230200400600
20172018201920202021202220230200400600

Publications

Publications (178)
Article
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Evidence from recent Mars landers identified the presence of perchlorates salts at 1 wt % in regolith and their widespread distribution on the Martian surface that has been hypothesized as a critical chemical hazard for putative life forms. However, the hypersaline environment may also potentially preserve life and its biomolecules over geological...
Article
Two rover missions to Mars aim to detect biomolecules as a sign of extinct or extant life with, among other instruments , Raman spectrometers. However, there are many unknowns about the stability of Raman-detectable bio-molecules in the martian environment, clouding the interpretation of the results. To quantify Raman-detectable biomolecule stabili...
Article
Full-text available
The question about the stability of certain biomolecules is directly connected to the life-detection missions aiming to search for past or present life beyond Earth. The extreme conditions experienced on extraterrestrial planet surface ( e.g. Mars), characterized by ionizing and non-ionizing radiation, CO 2 -atmosphere and reactive species, may des...
Article
The impact of global warming on biological communities colonizing European alpine ecosystems was recently studied. Hexagonal open top chambers (OTCs) were used for simulating a short‐term in situ warming (estimated around 1°C) in some alpine soils to predict the impact of ongoing climate change on resident microbial communities. Total microbial DNA...
Article
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The identification of traces of life beyond Earth (e.g., Mars, icy moons) is a challenging task because terrestrial chemical-based molecules may be destroyed by the harsh conditions experienced on extraterrestrial planetary surfaces. For this reason, studying the effects on biomolecules of extremophilic microorganisms through astrobiological ground...
Article
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The Moon is characterised by extremely harsh conditions due to ultraviolet irradiation, wide temperature extremes, vacuum resulting from the absence of an atmosphere, and high ionising radiation. Therefore, its surface may provide a unique platform to investigate the effects of such conditions. For lunar exploration with the Lunar Gateway platform,...
Article
As the European Alps are experiencing a strong climate warming; this study analyzed the soil microbiome at different altitudes and among different vegetation types at the Stelvio Pass (Italian Alps), aiming to i) characterize the composition and functional potential of the microbiome of soils and their gene expression during the peak vegetative sta...
Article
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The success of an astrobiological search for life campaign on Mars, or other planetary bodies in the Solar System, relies on the detectability of past or present microbial life traces, namely, biosignatures. Spectroscopic methods require little or no sample preparation, can be repeated almost endlessly, and can be performed in contact or even remot...
Article
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One of the main objectives of astrobiological research is the investigation of the habitability of other planetary bodies. Since space exploration missions are expensive and require long-term organization, the preliminary study of terrestrial environments is an essential step to prepare and support exploration missions. The Earth hosts a multitude...
Article
Mars is a primary target of astrobiological interest: its past environmental conditions may have been favourable to the emergence of a prebiotic chemistry and, potentially, biological activity. In situ exploration is currently underway at the Mars surface, and the subsurface (2 m depth) will be explored in the future ESA ExoMars mission. In this co...
Article
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The discovery of life on other planets and moons in our solar system is one of the most important challenges of this era. The second ExoMars mission will look for traces of extant or extinct life on Mars. The instruments on board the rover will be able to reach samples with eventual biomarkers until 2 m of depth under the planet’s surface. This exp...
Article
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In Victoria Land, Antarctica, ice-free areas are restricted to coastal regions and dominate the landscape of the McMurdo Dry Valleys. These two environments are subjected to different pressures that determine the establishment of highly adapted fungal communities. Within the kingdom of fungi, filamentous, yeasts and meristematic/microcolonial growt...
Article
Soil enzymatic activity was assessed in the Stelvio Pass area (Italian Central Alps) aiming to define the possible effects of climate change on microbial functioning. Two sites at two different elevations were chosen, a subalpine (2239 m) and an alpine belt (2604-2624 m), with mean annual air temperature differing by almost 3 °C, coherent with the...
Article
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Background Cryptoendolithic communities are microbial ecosystems dwelling inside porous rocks that are able to persist at the edge of the biological potential for life in the ice-free areas of the Antarctic desert. These regions include the McMurdo Dry Valleys, often accounted as the closest terrestrial counterpart of the Martian environment and t...
Article
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In the harshest environmental conditions of the Antarctic desert, normally incompatible with active life, microbes are adapted to exploit the cryptoendolithic habitat (i.e., pore spaces of rocks) and represent the predominant life-forms. In the rocky niche, microbes take advantage of the thermal buffering, physical stability, protection against UV...
Article
The diversity and composition of Antarctic cryptoendolithic microbial communities in the Mars-analogue site of Helliwell Hills (Northern Victoria Land, Continental Antarctica) is investigated, for the first time, applying both culture-dependent and high-throughput sequencing approaches. The study includes all the domains of the tree of life: Eukary...
Article
The McMurdo Dry Valleys surface is mainly constituted from unconsolidated permafrost. Despite the combination of cold and dry conditions, transiently wetted soils close to lake edges are hotspots of intense biological activity, that can support the surrounding soil ecosystems in such extreme environments. These soils host simple microbial communiti...
Article
Full-text available
Cryptoendolithic communities are almost the sole life form in the ice-free areas of the Antarctic desert, encompassing among the most extreme-tolerant organisms known on Earth that still assure ecosystems functioning, regulating nutrient and biogeochemical cycles under conditions accounted as incompatible with active life. If high-throughput sequen...
Chapter
The cryptoendolithic endemic black fungus Cryomyces antarcticus was first isolated from sandstone collected at Linnaeus Terrace, McMurdo Dry Valleys, Southern Victoria Land, Antarctica, by E.I. Friedmann in 1982, but published as a new species and genus in 2005. The McMurdo Dry Valleys are the coldest hyperarid desert on Earth and one of the best t...
Article
Full-text available
Among the celestial bodies in the Solar System, Mars currently represents the main target for the search for life beyond Earth. However, its surface is constantly exposed to high doses of cosmic rays (CRs) that may pose a threat to any biological system. For this reason, investigations into the limits of resistance of life to space relevant radiati...
Article
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One of the primary current astrobiological goals is to understand the limits of microbial resistance to extraterrestrial conditions. Much attention is paid to ionizing radiation, since it can prevent the preservation and spread of life outside the Earth. The aim of this research was to study the impact of accelerated He ions (150 MeV/n, up to 1 kGy...
Article
Five yeast strains were isolated from soil and sediments collected from Alps and Apennines glaciers during sampling campaigns carried out in summer 2007 and 2017, respectively. Based on morphological and physiological tests and on phylogenetic analyses reconstructed with ITS and D1/D2 sequences, the five strains were considered to belong to two rel...
Article
Climate warming in Greenland is facilitating the expansion of shrubs across wide areas of tundra. Given the close association between plants and soil microorganisms and the important role of soil bacteria in ecosystem functioning, it is of utmost importance to characterize microbial communities of arctic soil habitats and assess the influence of pl...
Article
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Melanin is a natural pigment present in almost all biological groups, and is composed of indolic polymers and characterized by black-brown colorization. Furthermore, it is one of the pigments produced by extremophiles including those living in the Antarctic desert, and is mainly involved in their protection from high UV radiation, desiccation, sali...
Article
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The endolithic niche represents an ultimate refuge to microorganisms in the Mars-like environment of the Antarctic desert. In an era of rapid global change and desertification, the interest in these border ecosystems is increasing due to speculation on how they maintain balance and functionality at the dry limits of life. To assure a reliable estim...
Article
A perennially frozen lake at Boulder Clay site (Victoria Land, Antarctica), characterized by the presence of frost mounds, have been selected as an in‐situ model for ecological studies. Different samples of permafrost, glacier ice and brines have been studied as a unique habitat system. An additional sample of brines (collected in another frozen la...
Article
Ice-free regions in coastal areas of Victoria Land, Antarctica, are patchily distributed, limited in extent and characterized by a simple vegetation of lichens and mosses, growing only for a short period during the austral summer. These organisms are associated with soil particles and microorganisms (e.g., algae, microfungi and bacteria) to make up...
Article
Full-text available
Antarctic cryptoendolithic communities are self-supporting borderline ecosystems spreading across the extreme conditions of the Antarctic desert and represent the predominant life-form in the ice-free areas of McMurdo Dry Valleys, accounted as the closest terrestrial Martian analogue. Components of these communities are highly adapted extremophiles...
Article
Full-text available
A draft genome sequence was assembled and annotated of the basidiomycetous yeast Rhodotorula sp. strain CCFEE 5036, isolated from Antarctic soil communities. The genome assembly is 19.07 megabases and encodes 6,434 protein-coding genes. The sequence will contribute to understanding the diversity of fungi inhabiting polar regions.
Article
The harsh environmental conditions of the ice-free regions of Continental Antarctica are considered one of the closest Martian analogues on Earth. There, rocks play a pivotal role as substratum for life and endolithism represents a primary habitat for microorganisms when external environmental conditions become incompatible with active life on rock...
Article
Full-text available
Antarctic cryptoendolithic communities are microbial ecosystems dwelling inside rocks of the Antarctic desert. We present the first 18 shotgun metagenomes from these communities to further characterize their composition, biodiversity, functionality, and adaptation. Future studies will integrate taxonomic and functional annotations to examine the pa...
Article
Full-text available
Describing the total biodiversity of an environmental metacommunity is challenging due to the presence of cryptic and rare species and incompletely described taxonomy. How many samples to collect is a common issue that faces ecologists when designing fieldwork sampling. Nowadays, high-throughput sequencing allows examination of large numbers of sam...
Preprint
Full-text available
Cryptoendolithic communities are microbial ecosystems dwelling inside porous rocks. They are able to persist at the edge of the biological potential for life in the ice-free areas of continental Antarctica. These areas include the McMurdo Dry Valleys, often cited as a Terrestrial analog of the Martian environment. Despite their interest as a model...
Article
Full-text available
The microbial communities that inhabit lithic niches inside sandstone in the Antarctic McMurdo Dry Valleys of life’s limits on Earth. The cryptoendolithic communities survive in these ice-free areas that have the lowest temperatures on Earth coupled with strong thermal fluctuations, extreme aridity, oligotrophy and high levels of solar and UV radia...
Article
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...
Conference Paper
One of the primary goals of the upcoming space missions is the search for signs of past or present life in rock deposit on Mars. This research mainly focuses on biosignatures that mostly include microbial fossils that could be preserved in the geological record also under high radiation levels. On Earth, there are limited environmental analogs (col...
Article
Fungi are the most abundant and one of the most diverse components of arctic soil ecosystems, where they are fundamental drivers of plant nutrient acquisition and recycling. Nevertheless, few studies have focused on the factors driving the diversity and functionality of fungal communities associated with these ecosystems, especially in the scope of...
Article
Full-text available
Fungi are the most abundant and one of the most diverse components of arctic soil ecosystems, where they are fundamental drivers of plant nutrient acquisition and recycling. Nevertheless, few studies have focused on the factors driving the diversity and functionality of fungal communities associated with these ecosystems, especially in the scope of...
Article
Endolithic growth within rocks is a critical adaptation of microbes living in harsh environments where exposure to extreme temperature, radiation, and desiccation limits the predominant life‐forms, such as in the ice‐free regions of Continental Antarctica. The microbial diversity of the endolithic communities in these areas has been sparsely examin...
Preprint
Full-text available
Antarctic cryptoendolithic communities are microbial ecosystems dwelling inside rocks of ice-free areas in Continental Antarctica. In Antarctica, these ecosystems were first described from the McMurdo Dry Valleys, accounted as the best analogous of the Martian environment on Earth and thought to be devoid of life until the discovery of these crypti...
Preprint
Full-text available
Antarctic cryptoendolithic communities are self-supporting borderline ecosystems spreading across the extreme conditions of the Antarctic desert and represent the most predominant life-form in the ice-free desert of McMurdo Dry Valleys, accounted as the closest terrestrial Martian analogue. Components of these communities are very adapted extremoph...
Preprint
Describing the total biodiversity of an environmental metacommunity is challenging due to the presence of cryptic and rare species and incompletely described taxonomy. How many samples to collect is a common issue faces ecologists when designing fieldwork sampling: collecting many samples may indeed capture the whole metacommunity structure, but ca...
Preprint
Full-text available
The harsh environmental conditions of the ice-free regions of Continental Antarctica are considered one of the closest Martian analogues on Earth. There, rocks play a pivotal role as substratum for life and endolithism represents a primary habitat for microorganisms when external environmental conditions become incompatible with active life on rock...
Article
Full-text available
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 pop...
Article
Full-text available
BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports—among others—the BIOMEX investigations into the stability and level of degradation of space-exposed biosign...
Conference Paper
Full-text available
Cryptoendolithic microbial communities, discovered in the extremely cold, hyper-arid McMurdo Dry Valleys of Antarctica (Friedmann 1982), the most similar terrestrial environments to Mars surface (Wynn-Williams and Edwards 2000; Onofri et al., 2004), have been considered as a candidate in supporting the search of life in Mars exploration. In such ha...
Article
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 antar...
Article
Despite living organisms are not exposed to acute ionizing radiation under natural conditions, some exhibit a high radiation resistance. Understanding this phenomenon is important for assessing the impact of radiation-related accidents, occupational exposures and space missions. In this context, in this study we analyzed the effect of gamma rays on...
Conference Paper
The cryptoendolithic black fungus Cryomyces antarcticus inhabits the ice-free area of the Antarctic McMurdo Dry Valleys, one of the best terrestrial analogue environment for Mars. There, conditions on rock surface are often incompatible with life; hence, microbes develop within porous rocks as last chance for survival. The almost complete isolation...
Article
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...
Article
Full-text available
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 fac...
Article
Full-text available
Antarctic cryptoendolithic microbial communities dominate ice-free areas of continental Antarctica, among the harshest environments on Earth. The endolithic lifestyle is a remarkable adaptation to the exceptional environmental extremes of this area, which is considered the closest terrestrial example to conditions on Mars. Recent efforts have attem...
Article
Full-text available
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...
Article
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The aim of this study was to analyze how protracted exposure to X-rays delivered at low dose rates of 0.0032–0.052 kGy/h affects the survival and metabolic activity of two microfungi capable of melanogenesis: fast-growing Cryptococcus neoformans (CN) and slow-growing Cryomyces antarcticus (CA). Melanized CN and CA cells survived the protracted expo...
Article
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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 studi...
Article
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...
Article
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Knowledge of the relationships and thus the classification of fungi, has developed rapidly with increasingly widespread use of molecular techniques, over the past 10–15 years, and continues to accelerate. Several genera have been found to be polyphyletic, and their generic concepts have subsequently been emended. New names have thus been introduced...
Article
In restoration and conservation practices, biocide treatments are considered one of the most practical approaches to remove biological colonization on artworks, including stone. Numerous studies have focused on the short- and long-term effects of these treatments and recently many alternative methods to reduce their potential hazards to human healt...
Article
Full-text available
The draft genome sequences of Rachicladosporium antarcticum CCFEE 5527 and Rachicladosporium sp. CCFEE 5018 are the first sequenced genomes from this genus, which comprises rock-inhabiting fungi. These endolithic strains were isolated from inside rocks collected from the Antarctic Peninsula and Battleship Promontory (McMurdo Dry Valleys), Antarctic...
Article
Full-text available
Scientists use the Earth as a tool for astrobiology by analyzing planetary field analogues (i.e. terrestrial samples and field sites that resemble planetary bodies in our Solar System). In addition, they expose the selected planetary field analogues in simulation chambers to conditions that mimic the ones of planets, moons and Low Earth Orbit (LEO)...
Article
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The space environment is regularly used for experiments addressing astrobiology research goals. The specific conditions prevailing in Earth orbit and beyond, notably the radiative environment (photons and energetic particles) and the possibility to conduct long-duration measurements, have been the main motivations for developing experimental concep...