Search Results (41)

Despite their vital physiological roles, oxidative imbalance caused by reactive oxygen, nitrogen, sulphur, and chlorine species damages essential body macromolecules such as proteins, lipids, and nucleic acids through oxidative stress. This stress is strongly associated with cancer, inflammation, neurological and cardiovascular disorders, and other chronic human diseases. Therefore, antioxidants, natural or synthetic, that counteract oxidative damage are important, with increasing interest in their use within the pharmaceutical, food, and cosmetic industries. However, due to toxicity concerns with the synthetic variants, natural antioxidants are increasingly preferred. Extremophile-derived antioxidants, such as superoxide dismutases, catalases, peroxidases, carotenoids, and melanin, are of renewed interest due to their remarkable stability, robustness, and potency under extreme conditions of temperature, pH, and salinity. These make them better than many mesophile-derived antioxidants and excellent candidates for cost-effective biotechnological, research, and industrial processes that require high operational efficiency. This review summarises key classes of selected enzymatic and pigment antioxidants, their mechanisms of action, and their industrial relevance, with a focus on extremophilic microalgae, bacteria, and fungi. The benefits of extremophilic antioxidants are discussed alongside their current applications and existing challenges, including the need to develop efficient delivery systems, scalability issues, and limited characterisation. Full article

Fungi, including yeasts, have played a central role in the development of knowledge about cell physiology and molecular biology as experimental eukaryotic models. However, much of this knowledge has been generated using classical organisms such as Saccharomyces cerevisiae, which display inherent limitations, as many cellular processes operate under extreme conditions, including high salinity, extreme pH, oxidative stress, exposure to toxic compounds, and temperature fluctuations. In this context, extremophilic and extremotolerant yeasts have emerged as complementary systems with strong potential for basic research and biotechnological applications. This review integrates recent advances in the taxonomic diversity, ecology, physiology, molecular mechanisms, and omics-based analyses of extremophilic yeasts, with a particular focus on how these organisms achieve stress integration through coordinated regulation of signaling pathways, metabolism, and organelle function. We discuss representative applications in environmental toxicology, bioremediation, and industrial bioprocesses, as well as their relevance in the context of climate change and space biotechnology. Finally, we outline key conceptual and methodological challenges and propose future perspectives that position extremophilic yeasts as next-generation eukaryotic models for investigating adaptation as a systems-level, constitutive cellular state under complex and dynamic stress conditions. Full article

Caves and other subterranean ecosystems are characterized by stable, low temperatures, high humidity, and limited nutrient input, creating unique environments for extremophilic microorganisms. Among them, fungi play key roles in organic matter degradation, mineral interactions, and biogeochemical cycling, yet the diversity and adaptations of cold-adapted fungi in cave habitats remain insufficiently explored. This study investigated psychrophilic and psychrotolerant fungi inhabiting the stone surfaces of Ravništarka Cave in Eastern Serbia. Biofilm samples were collected from nine sites and analyzed using culture-based isolation on both nutrient-rich and diluted media, followed by incubation at 10 °C, 25 °C, and 37 °C. Fungal identification combined morphological characteristics with molecular analyses of the ITS region and BenA gene, while ecological roles were assigned using FUNGuild. A total of 41 fungal species were documented, spanning Ascomycota (53.1%), Basidiomycota (43.7%), and Mortierellomycota (3.1%) phyla. The genus Penicillium exhibited the greatest species richness, with 14 taxa documented, including P. chrysogenum, P. glandicola, and P. solitum, all previously associated with cold or oligotrophic environments. The psychrotolerant species Mortierella alpina was the only representative of Mortierellomycota. Ecological guild assignment revealed fungi functioning at different trophic levels, highlighting their multifunctional ecological roles in extreme subterranean habitats. Full article

Background/Objectives: We evaluated eukaryotic diversity in two cores obtained from abyssal sediments collected at depths of 4280 m and 4444 m in the equatorial Atlantic, between the Fernando de Noronha and São Pedro and São Paulo archipelagos, using a DNA metabarcoding approach applied to environmental DNA (eDNA) samples. Results: In total, we detected 248,905 DNA reads that were assigned to 65 amplicon sequence variants (ASVs) in the two core sediments (176,073 DNA reads and 59 ASVs were detected in sediment obtained at 4280 m depth, and 72,832 DNA reads and 14 ASVs were detected in the core at 4444 m). These represented three Kingdoms and five phyla: Fungi (Ascomycota and Basidiomycota), Viridiplantae (Chlorophyta and Streptophyta) and Chromista (Ciliophora), in rank abundance order. Ascomycota was the dominant phylum, followed by Basidiomycota. Didymella sp., Cladosporium sp., Scopulariopsis sp., Alternaria eichhorniae, Curvularia sp., Hortaea werneckii, Penicillium sp. (Ascomycota) and Malassezia globosa (Basidiomycota) were the most abundant taxa. Pseudochlorella pyrenoidosa (Chlorophyta) was the most abundant representative of Viridiplantae detected, and Spirotrachelostyla tani (Ciliophora) was the only Chromista detected, both present as minor components of the assigned eukaryotic diversity and only in the 4280 m core. The eukaryotic assemblages displayed moderate diversity indices, and those from the deeper core (4444 m depth) displayed the highest diversity values. Few assigned taxa were present in both samples. The two cores differed in their geological characteristics, consistent with their location in different depositional basins. The core obtained at 4280 m depth, located further north and more isolated from the adjacent continent by two fracture zones, appears to receive less terrigenous sediment input. In contrast, the core obtained at 4444 m depth is under greater continental influence and receives more terrigenous input from the continent. These geological and geographic differences may contribute to the varying eukaryotic eDNA diversities found. Results: Our metabarcoding study revealed the presence of a sediment eukaryotic community dominated by fungi. This included assigned ASVs representing groups with different ecological roles, such as cosmopolitan and phytopathogenic members and extremophiles, some of which may be able to survive and function in the polyextreme deep-sea abyssal conditions. Abyssal sediments present a potential habitat for studying organisms at the edge of viable conditions for life on Earth. eDNA metabarcoding provides a promising technique for detecting cryptic and uncultured biodiversity compared to traditional approaches, opening avenues for further ecological, evolutionary and biotechnological studies. Full article

The Qinghai–Tibet Plateau (QTP) harbors extreme environmental conditions (e.g., low temperature, intense UV radiation, and hypoxia), presenting unique challenges for biological adaptation. However, the genetic mechanisms underlying the adaptation of macrofungi to high-altitude environments on the QTP remain poorly understood. In this study, we de novo sequenced and assembled the genomes of three Laccaria species collected from the QTP, aiming to unravel the genomic basis of their adaptation to high altitudes. The genomic data indicates that the genome of high-altitude species is slightly larger than that of their low-altitude relatives, particularly due to LTR retrotransposons, which also show a negative correlation with altitude. The expanded and positively selected gene families in high-altitude species were enriched in pathways related to DNA damage repair, maintenance of cell membrane stability, signal transduction, enzyme activity, stress response, and reproduction. In contrast, contracted gene families in high-altitude species were primarily associated with disease and immune responses, likely due to the reduced pathogen pressure in extreme high-altitude environments. Additionally, species-specific genes of high-altitude Laccaria were enriched in functions related to enzyme activity, membrane stability, and signal transduction, further supporting their adaptive roles. Analysis of carbohydrate-active enzymes (CAZymes) showed distinct gene family distributions between high- and low-altitude species, with several families absent in the low-altitude species, suggesting their potential involvement in environmental adaptation. Overall, our findings indicate that genome size expansion driven by LTR retrotransposons, coordinated evolution of gene families, positive selection, and divergence in CAZymes collectively may contribute to the adaptation of Laccaria to extreme high-altitude environments. This study provides basic data into the genetic mechanisms of fungal adaptation to harsh plateau environments and lays a foundation for further research on extremophilic fungi. Full article

Canvas paintings are prone to biodeterioration due to their complex chemical composition, which can support fungal growth even under controlled conditions. This study evaluated the susceptibility of common synthetic restoration materials—Lascaux glues (303 HV, 498 HV), Acrylharz P550, BEVA 371, Laropal A81, and Regalrez 1094—to degradation by fourteen xerotolerant/xerophilic fungal strains. All tested Aspergillus and Penicillium species extensively colonized, especially artificially aged materials. FTIR-PAS analysis revealed chemical changes in carbonyl and C–H bonds in Laropal A81 and Regalrez 1094 colonized by Aspergillus spp. Scanning electron microscopy (SEM) imaging showed thinning of Lascaux glues and deformation of Regalrez 1094. Transcriptomic profiling of A. puulaauensis grown on Lascaux 498 HV and Regalrez 1094 identified altered expression of genes coding for esterases and oxidases, enzymes involved in synthetic polymer degradation. Esterase activity assays using 4-nitrophenol-based substrates confirmed significant enzymatic activity correlating with the presence of ester bonds. These findings highlight the vulnerability of synthetic restoration materials, specifically Laropal A81, Regalrez 1094, and Lascaux glues, to extremophilic fungi thriving in environments with low water activity. The results emphasize the urgent need for specific knowledge on fungi and their metabolic pathways to use/develop more durable conservation materials and strategies to protect cultural heritage objects from biodeterioration. Full article

Antimicrobial resistance represents one of the most critical public health challenges of the 21st century. The emergence of multidrug resistance (MDR) in bacterial and fungal pathogens to diverse chemical agents severely impedes the effective treatment of diseases such as cancer and systemic infections. The rapid escalation of microbial resistance underscores the urgent need for the discovery of novel antimicrobial agents and innovative approaches to drug development. In both clinical and industrial contexts, the identification of new antibiotics and antifungals remains pivotal for pathogen control. Current research efforts focus on the development of alternative formulations that offer high efficacy, reduced resistance potential, minimal side effects, and synergistic interactions, particularly those derived from natural sources. Filamentous fungi originating from extreme environments have evolved to thrive under harsh conditions, making them promising reservoirs of bioactive metabolites with unique structural and functional properties. These fungi exhibit potent antimicrobial activity through diverse mechanisms that disrupt essential cellular processes in pathogens. Despite their remarkable potential, the bioprospecting of extremophilic filamentous fungi for drug development remains underexplored. This highlights the necessity for expanded research into the efficacy and safety of their derived compounds. This review aims to emphasize the capacity of extremophilic fungi to produce antimicrobial agents, elucidate resistance mechanisms, characterize fungal bioactive extracts, and analyze their molecular actions in the context of their extreme ecological niches. Full article

Often thought of as a mesic paradise, forest ecosystems are a mosaic of microhabitats with temporal oscillations that cause significant environmental stresses, providing habitats for extremophilic and extremotolerant fungi. Adapted to survive and thrive under conditions lethal to most mesophiles (e.g., extreme temperatures, pH, water potential, radiation, salinity, nutrient scarcity, and pollutants), these species are increasingly recognized as vital yet underappreciated elements of forest biodiversity and function. This review examines the current understanding of the roles of extremophilic fungi in forests, scrutinizing their presence in these ecosystems with a critical eye. Particularly under severe environmental conditions, extremophilic fungi play a crucial role in forest ecosystems, as they significantly enhance decomposition and nutrient cycling, and foster mutualistic interactions with plants that increase stress resilience. This helps to maintain ecosystem stability. We examine the definition of “extreme” within forest settings, survey the known diversity and distribution of these fungi across various forest stress niches (cold climates, fire-affected areas, acidic soils, canopy surfaces, polluted sites), and delve into their possible ecological functions, including decomposition of recalcitrant matter, nutrient cycling under stress, interactions with plants (pathogenesis, endophytism, perhaps mycorrhizae), bioremediation, and contributions to soil formation. However, the review stresses significant methodological difficulties, information gaps, and field-based natural biases. We recommend overcoming cultural constraints, enhancing the functional annotation of “omics” data, and planning investigations that clarify the specific activities and interactions of these cryptic creatures within the forest matrix to further advance the field. Here, we demonstrate that moving beyond simple identification to a deeper understanding of function will enable us to more fully appreciate the value of extremophilic fungi in forest ecosystems, particularly in relation to environmental disturbances and climate change. Full article

Drought and metal pollution severely impact plant growth. Root-associated extremophilic fungi can improve plant performance, and their encapsulation improves protection and effectiveness. This study optimized the encapsulation conditions for an extremophilic fungus with plant growth-promoting traits using alginate–chitosan capsules. An endophytic fungus was isolated from the roots of Neltuma chilensis from the Atacama Desert and identified via internal transcribed spacer (ITS) sequencing. Its plant growth-promoting traits, including exopolysaccharide, ammonium, siderophore, and indole acetic acid production and phosphorus solubilization, were evaluated. Freeze-dried Penicillium nalgiovense was encapsulated using jet-breaking extrusion, and capsule morphology and fungal survival were assessed via scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM), and viability tests. Using Taguchi’s design, optimal conditions for sphericity (0.914 ± 0.002) and mean size (3.232 ± 0.087 mm) were achieved with 1% chitosan, a 5 cm distance to the gelation bath, and a 40 Hz vibration frequency. CLSM analysis confirmed the presence of the chitosan outer layer, revealing the capsule’s coating material encapsulating the fungus P. nalgiovense. The encapsulated fungus remained viable across disinfection times, demonstrating effective protection and gradual release. These findings emphasize the need for precise parameter control in fungal encapsulation, providing a basis for developing robust bioinoculants to support plant resilience in extreme environments. Full article

Although certain hypersaline endorheic lagoons in Spain have been investigated to evaluate the composition, spatial structure, and ecological roles of their macro- and microbiota, the fungi inhabiting these niches remain largely unexplored. In this study, we isolated several microfungi from the Salada Grande de Chiprana and La Playa lagoons, located in the Saladas de Chiprana (Directed Natural Reserve and Ramsar Wetland) and the Saladas de Sástago–Bujaraloz (Ramsar Wetland), respectively. As a result of morphological characterization and phylogenetic analysis using four informative molecular markers, we report the discovery of two new species of the genus Montagnula (M.), M. globospora and M. terricola, as well as one new species of Monosporascus (Mo.), Mo. auratispora. Montagnula globospora, isolated from a sediment sample from Salada Grande de Chiprana lagoon, is the only species of the genus producing unicellular, globose ascospores inside cleistothecial ascomata with a cephalothecoid peridium. Montagnula terricola was originally isolated from a soil sample in Malawi (ex-type strain). However, we have also identified another strain of this species from a sediment sample collected at La Playa lagoon. The remarkable features of M. terricola are the production of non-cephalothecoid cleistothecial ascomata and bicellular, bi-cupulate ascospores. Regarding Mo. auratispora, it was isolated from sediments of Salada Grande de Chiprana and is characterized by the production of golden-brown ascospores that do not turn black with age. Also, due to the results of our phylogenetic analysis, we transferred Herpotrichia striatispora to the genus Montagnula, as M. striatispora, and Montangula jonessi to the new genus Neomontagnula (N.), as N. jonessi. Full article

Extremophiles are of significant scientific interest due to their unique adaptation to harsh environmental conditions and their potential for diverse biotechnological applications. Among these extremophiles, filamentous fungi adapted to high-salt environments represent a new and valuable source of enzymes, biomolecules, and biomaterials. While most studies on halophiles have focused on bacteria, reports on filamentous fungi remain limited. This review compiles information about salt-adapted fungi and details their distribution, adaptation mechanisms, and potential applications in various societal areas. Understanding the adaptive mechanisms of halophilic fungi not only sheds light on the biology of extremophilic fungi but also leads to promising biotechnological applications, including the development of salt-tolerant enzymes and strategies for bioremediation of saline habitats. To fully realize this potential, a comprehensive understanding of their ecology, diversity and physiology is crucial. In addition, understanding their survival mechanisms in saline environments is important for the development of astrobiology. The significant potential of applications of halophilic fungi is highlighted. Full article

The conservation of the Antarctic ecosystem is linked to scientific and tourism activities. The Colección Activa de Plantas Vasculares Antárticas at the Universidad de Concepción aims to help conserve the region’s vascular flora to support scientific research while minimizing anthropogenic pressure on natural ecosystems. Colobanthus quitensis is the only native dicotyledonous plant native to Antarctica and, as an extremophilic plant, is capable of withstanding extreme abiotic conditions. This species has potentially important use as a biological model to study the physiological deterioration of dormant seeds and other traits, some of which may contribute to vegetation development in Antarctica. Although studies have addressed the reproduction and germination of C. quitensis, there is no recent synthesis of information regarding its reproductive biology and seed traits that could support its conservation. This work synthesizes and critically analyzes the current knowledge of C. quitensis reproduction in natural and controlled environments, identifying factors that contribute to the decline in seed quality. We propose that growth conditions, seed morphology, and interactions with endophytic fungi influence germination and seedling establishment. We also highlight critical knowledge gaps that must be addressed to better understand the species’ phenology, the impact of biotic and abiotic factors on its development, strategies for seed conservation, and biotechnological applications. Full article

Climate change and the resultant environmental deterioration signify one of the most challenging problems facing humankind in the 21st century. The origins of climate change are multifaceted and rooted in anthropogenic activities, resulting in increasing greenhouse gases in the environment and leading to global warming and weather drifts. Extremophilic fungi, characterized by their exceptional properties to survive extreme habitats, harbor great potential in mitigating climate change effects. This review provides insight into the potential applications of extremophilic fungi in climate change mitigation strategies. They are able to metabolize organic biomass and degrade carbon compounds, thereby safely sequestering carbon and extenuating its release into the environment as noxious greenhouse gases. Furthermore, they possess extremozymes, which break down recalcitrant organic species, including lignocellulosic biomass and hydrocarbons. Enzymatic machinery equips these extremophilic fungi to perform the bioremediation of polluted environments. Extremophilic fungi can also be exploited for various biological interventions, such as biofuels, bioplastics, and other bioprocessing applications. However, these fungi characterize a valued but underexplored resource in the arsenal of climate change mitigation strategies. Full article

The pressing demand for novel compounds to address contemporary health challenges has prompted researchers to venture into uncharted territory, including extreme ecosystems, in search of new natural pharmaceuticals. Fungi capable of tolerating extreme conditions, known as extremophilic fungi, have garnered attention for their ability to produce unique secondary metabolites crucial for defense and communication, some of which exhibit promising clinical significance. Among these, halophilic fungi thriving in high-salinity environments have particularly piqued interest for their production of bioactive molecules. This review highlights the recent discoveries regarding novel compounds from halotolerant fungal strains isolated from various saline habitats. From diverse fungal species including Aspergillus, Penicillium, Alternaria, Myrothecium, and Cladosporium, a plethora of intriguing molecules have been elucidated, showcasing diverse chemical structures and bioactivity. These compounds exhibit cytotoxicity against cancer cell lines such as A549, HL60, and K-562, antimicrobial activity against pathogens like Escherichia coli, Bacillus subtilis, and Candida albicans, as well as radical-scavenging properties. Notable examples include variecolorins, sclerotides, alternarosides, and chrysogesides, among others. Additionally, several compounds display unique structural motifs, such as spiro-anthronopyranoid diketopiperazines and pentacyclic triterpenoids. The results emphasize the significant promise of halotolerant fungi in providing bioactive compounds for pharmaceutical, agricultural, and biotechnological uses. However, despite their potential, halophilic fungi are still largely unexplored as sources of valuable compounds. Full article

The Saladas de Sástago-Bujaraloz is an endorheic and arheic complex of lagoons located in the Ebro Basin and protected by the Ramsar Convention on Wetlands. Due to the semi-arid climate of the region and the high salinity of their waters, these lagoons constitute an extreme environment. We surveyed the biodiversity of salt-tolerant and halophilic fungi residents of the Laguna de Pito, a lagoon belonging to this complex. Therefore, we collected several samples of water, sediments, and soil of the periphery. Throughout the study, we isolated 21 fungal species, including a strain morphologically related to the family Microascaceae. However, this strain did not morphologically match any of genera within this family. After an in-depth morphological characterization and phylogenetic analysis using a concatenated sequence dataset of four phylogenetically informative molecular markers (the internal transcribed spacer region (ITS) of the nuclear ribosomal DNA (nrDNA); the D1-D2 domains of the 28S gene of the nuclear ribosomal RNA (LSU); and a fragment of the translation elongation factor 1-alpha (EF-1α) and the β-tubulin (tub2) genes), we established the new genus Dactyliodendromyces, with Dactyliodendromyces holomorphus as its species. Additionally, as a result of our taxonomic study, we reclassified the paraphyletic genus Wardomyces into three different genera: Wardomyces sensu stricto, Parawardomyces gen. nov., and Pseudowardomyces gen. nov., with Parawardomyces ovalis (formerly Wardomyces ovalis) and Pseudowardomyces humicola (formerly Wardomyces humicola) as the type species of their respective genera. Furthermore, we propose new combinations, including Parawardomyces giganteus (formerly Wardomyces giganteus) and Pseudowardomyces pulvinatus (formerly Wardomyces pulvinatus). Full article