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Azua-Bustos A, González-Silva C, Freedman K, Carrizo D, Sánchez-García L, Fernández-Martínez MÁ, Balsera-Manzanero M, Muñoz-Iglesias V, Fernández-Sampedro M, Dang TQ, Vargas-Carrera C, Wierzchos J. Sea spray allows for the growth of subaerial microbialites at the driest desert on Earth. Sci Rep 2024; 14:19915. [PMID: 39198637 PMCID: PMC11358262 DOI: 10.1038/s41598-024-70447-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 08/16/2024] [Indexed: 09/01/2024] Open
Abstract
Due to its extreme conditions, microbial life in the Atacama Desert is known to survive in well-protected micro-habitats (hypolithic, endolithic, etc.), but rarely directly exposed to the environment, that is, epilithic habitats. Here we report a unique site, La Portada, a cliff confronting the Pacific Ocean in the Coastal Range of this desert, in which the constant input of water provided by the sea spray allows for the growth of a black-colored epilithic subaerial microbial ecosystem. Formed by a complex community of halophilic microorganisms belonging to the three domains of life, this ecosystem displays the typical three-dimensional structure of benthic microbialites, coherent with the presence of a diversity of cyanobacteria (including species from the genera that are known to form them), a constant high water activity and an ample availability of carbonate ions. From these microbialites we isolated Hortae werneckii, a fungal species which by producing melanin, not only explains the dark color of these microbialites, but may also play the role of protecting the whole community from extreme UV radiation. A number of biosignatures not only confirmed sea spray as the main source of water, but also suggests that one place to consider for the search of evidences of life on Mars would be on the paleo-coastlines that surrounded vanished oceans such as that on Aeolis Dorsa.
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Affiliation(s)
| | | | | | - Daniel Carrizo
- Centro de Astrobiología (CAB), CSIC-INTA, 28850, Madrid, Spain
| | | | - Miguel Ángel Fernández-Martínez
- Departamento de Ecología, Facultad de Ciencias, Universidad Autónoma de Madrid y Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Madrid, Spain
| | | | - Victoria Muñoz-Iglesias
- Centro de Astrobiología (CAB), CSIC-INTA, 28850, Madrid, Spain
- Laboratoire de Planétologie et Géosciences, CNRS, LPG UMR 6112, Nantes Université, Univ Angers, Le Mans Université, 44000, Nantes, France
| | | | | | | | - Jacek Wierzchos
- Museo Nacional de Ciencias Naturales (CSIC), 28006, Madrid, Spain
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2
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Liang MH, Xie SR, Dai JL, Chen HH, Jiang JG. Roles of Two Phytoene Synthases and Orange Protein in Carotenoid Metabolism of the β-Carotene-Accumulating Dunaliella salina. Microbiol Spectr 2023; 11:e0006923. [PMID: 37022233 PMCID: PMC10269666 DOI: 10.1128/spectrum.00069-23] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/16/2023] [Indexed: 04/07/2023] Open
Abstract
Phytoene synthase (PSY) is a key enzyme in carotenoid metabolism and often regulated by orange protein. However, few studies have focused on the functional differentiation of the two PSYs and their regulation by protein interaction in the β-carotene-accumulating Dunaliella salina CCAP 19/18. In this study, we confirmed that DsPSY1 from D. salina possessed high PSY catalytic activity, whereas DsPSY2 almost had no activity. Two amino acid residues at positions 144 and 285 responsible for substrate binding were associated with the functional variance between DsPSY1 and DsPSY2. Moreover, orange protein from D. salina (DsOR) could interact with DsPSY1/2. DbPSY from Dunaliella sp. FACHB-847 also had high PSY activity, but DbOR could not interact with DbPSY, which might be one reason why it could not highly accumulate β-carotene. Overexpression of DsOR, especially the mutant DsORHis, could significantly improve the single-cell carotenoid content and change cell morphology (with larger cell size, bigger plastoglobuli, and fragmented starch granules) of D. salina. Overall, DsPSY1 played a dominant role in carotenoid biosynthesis in D. salina, and DsOR promoted carotenoid accumulation, especially β-carotene via interacting with DsPSY1/2 and regulating the plastid development. Our study provides a new clue for the regulatory mechanism of carotenoid metabolism in Dunaliella. IMPORTANCE Phytoene synthase (PSY) as the key rate-limiting enzyme in carotenoid metabolism can be regulated by various regulators and factors. We found that DsPSY1 played a dominant role in carotenogenesis in the β-carotene-accumulating Dunaliella salina, and two amino acid residues critical in the substrate binding were associated with the functional variance between DsPSY1 and DsPSY2. Orange protein from D. salina (DsOR) can promote carotenoid accumulation via interacting with DsPSY1/2 and regulating the plastid development, which provides new insights into the molecular mechanism of massive accumulation of β-carotene in D. salina.
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Affiliation(s)
- Ming-Hua Liang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Ecological Science, School of Life Sciences, South China Normal University, Guangzhou, China
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Shan-Rong Xie
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Jv-Liang Dai
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Hao-Hong Chen
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Jian-Guo Jiang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
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3
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Wynne JJ, Titus TN, Agha‐Mohammadi A, Azua‐Bustos A, Boston PJ, de León P, Demirel‐Floyd C, De Waele J, Jones H, Malaska MJ, Miller AZ, Sapers HM, Sauro F, Sonderegger DL, Uckert K, Wong UY, Alexander EC, Chiao L, Cushing GE, DeDecker J, Fairén AG, Frumkin A, Harris GL, Kearney ML, Kerber L, Léveillé RJ, Manyapu K, Massironi M, Mylroie JE, Onac BP, Parazynski SE, Phillips‐Lander CM, Prettyman TH, Schulze‐Makuch D, Wagner RV, Whittaker WL, Williams KE. Fundamental Science and Engineering Questions in Planetary Cave Exploration. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2022; 127:e2022JE007194. [PMID: 36582809 PMCID: PMC9787064 DOI: 10.1029/2022je007194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 06/17/2023]
Abstract
Nearly half a century ago, two papers postulated the likelihood of lunar lava tube caves using mathematical models. Today, armed with an array of orbiting and fly-by satellites and survey instrumentation, we have now acquired cave data across our solar system-including the identification of potential cave entrances on the Moon, Mars, and at least nine other planetary bodies. These discoveries gave rise to the study of planetary caves. To help advance this field, we leveraged the expertise of an interdisciplinary group to identify a strategy to explore caves beyond Earth. Focusing primarily on astrobiology, the cave environment, geology, robotics, instrumentation, and human exploration, our goal was to produce a framework to guide this subdiscipline through at least the next decade. To do this, we first assembled a list of 198 science and engineering questions. Then, through a series of social surveys, 114 scientists and engineers winnowed down the list to the top 53 highest priority questions. This exercise resulted in identifying emerging and crucial research areas that require robust development to ultimately support a robotic mission to a planetary cave-principally the Moon and/or Mars. With the necessary financial investment and institutional support, the research and technological development required to achieve these necessary advancements over the next decade are attainable. Subsequently, we will be positioned to robotically examine lunar caves and search for evidence of life within Martian caves; in turn, this will set the stage for human exploration and potential habitation of both the lunar and Martian subsurface.
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Affiliation(s)
- J. Judson Wynne
- Department of Biological Sciences and Center for Adaptable Western LandscapesNorthern Arizona UniversityFlagstaffAZUSA
| | | | | | - Armando Azua‐Bustos
- Centro de AstrobiologíaCSIC‐INTAUnidad María de MaeztuInstituto Nacional de Técnica Aeroespacial Ctra de Torrejón a AjalvirMadridSpain
- Instituto de Ciencias BiomédicasFacultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile
| | | | - Pablo de León
- Human Spaceflight LaboratoryDepartment of Space StudiesUniversity of North DakotaGrand ForksNDUSA
| | | | - Jo De Waele
- Department of Biological, Geological and Environmental SciencesUniversity of BolognaBolognaItaly
| | - Heather Jones
- Robotics InstituteCarnegie Mellon UniversityPittsburghPAUSA
| | - Michael J. Malaska
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Ana Z. Miller
- Laboratório HERCULESUniversity of ÉvoraÉvoraPortugal
- Instituto de Recursos Naturales y AgrobiologíaConsejo Superior de Investigaciones CientíficasSevilleSpain
| | - Haley M. Sapers
- Department of Earth and Space Science and EngineeringYork UniversityTorontoONCanada
| | - Francesco Sauro
- Department of Biological, Geological and Environmental SciencesUniversity of BolognaBolognaItaly
| | - Derek L. Sonderegger
- Department of Mathematics and StatisticsNorthern Arizona UniversityFlagstaffAZUSA
| | - Kyle Uckert
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | | | - E. Calvin Alexander
- Earth and Environmental Sciences DepartmentUniversity of MinnesotaMinneapolisMNUSA
| | - Leroy Chiao
- Department of Mechanical EngineeringRice UniversityHoustonTXUSA
| | - Glen E. Cushing
- U.S. Geological SurveyAstrogeology Science CenterFlagstaffAZUSA
| | - John DeDecker
- Center for Mineral Resources ScienceColorado School of MinesGoldenCOUSA
| | - Alberto G. Fairén
- Centro de AstrobiologíaCSIC‐INTAUnidad María de MaeztuInstituto Nacional de Técnica Aeroespacial Ctra de Torrejón a AjalvirMadridSpain
- Department of AstronomyCornell UniversityIthacaNYUSA
| | - Amos Frumkin
- Institute of Earth SciencesThe Hebrew UniversityJerusalemIsrael
| | - Gary L. Harris
- Human Spaceflight LaboratoryDepartment of Space StudiesUniversity of North DakotaGrand ForksNDUSA
| | - Michelle L. Kearney
- Department of Astronomy and Planetary SciencesNorthern Arizona UniversityFlagstaffAZUSA
| | - Laura Kerber
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Richard J. Léveillé
- Department of Earth and Planetary SciencesMcGill UniversityMontrealQCCanada
- Geosciences DepartmentJohn Abbott CollegeSte‐Anne‐de‐BellevueQCCanada
| | | | - Matteo Massironi
- Dipartimento di GeoscienzeUniversità degli Studi di PadovaPadovaItaly
| | - John E. Mylroie
- Department of GeosciencesMississippi State UniversityStarkvilleMSUSA
| | - Bogdan P. Onac
- School of GeosciencesUniversity of South FloridaTampaFLUSA
- Emil G. Racoviță InstituteBabeș‐Bolyai UniversityCluj‐NapocaRomania
| | | | | | | | - Dirk Schulze‐Makuch
- Astrobiology GroupCenter of Astronomy and AstrophysicsTechnische Universität BerlinBerlinGermany
- Section GeomicrobiologyGFZ German Research Centre for GeosciencesPotsdamGermany
- Department of Experimental LimnologyLeibniz‐Institute of Freshwater Ecology and Inland Fisheries (IGB)StechlinGermany
| | - Robert V. Wagner
- School of Earth and Space ExplorationArizona State UniversityTempeAZUSA
| | - William L. Whittaker
- Department of Biological, Geological and Environmental SciencesUniversity of BolognaBolognaItaly
| | - Kaj E. Williams
- U.S. Geological SurveyAstrogeology Science CenterFlagstaffAZUSA
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4
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Coleine C, Delgado-Baquerizo M. Unearthing terrestrial extreme microbiomes for searching terrestrial-like life in the Solar System. Trends Microbiol 2022; 30:1101-1115. [PMID: 35568658 DOI: 10.1016/j.tim.2022.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/03/2022] [Accepted: 04/11/2022] [Indexed: 01/13/2023]
Abstract
The possibility of life elsewhere in the universe has fascinated humankind for ages. To the best of our knowledge, life, as we know it, is limited to planet Earth; yet current investigation suggests that life might be more common than previously thought. In this review, we explore extreme terrestrial analogue environments in the search for some notable examples of extreme organisms, including overlooked microbial groups such as viruses, fungi, and protists, associated with limits of life on Earth. This knowledge is integral to provide the foundational principles needed to predict what sort of Earth-like organisms we might find in the Solar System and beyond, and to understand the future and origins of life on Earth.
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Affiliation(s)
- Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia, 01100 Viterbo, Italy.
| | - Manuel Delgado-Baquerizo
- Laboratorio de Biodiversidad y Funcionamiento Ecosistémico. Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Av. Reina Mercedes 10, E-41012, Sevilla, Spain; Unidad Asociada CSIC-UPO (BioFun). Universidad Pablo de Olavide, 41013 Sevilla, Spain.
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5
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Gostinčar C, Sun X, Černoša A, Fang C, Gunde-Cimerman N, Song Z. Clonality, inbreeding, and hybridization in two extremotolerant black yeasts. Gigascience 2022; 11:giac095. [PMID: 36200832 PMCID: PMC9535773 DOI: 10.1093/gigascience/giac095] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/29/2022] [Accepted: 09/12/2022] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND The great diversity of lifestyles and survival strategies observed in fungi is reflected in the many ways in which they reproduce and recombine. Although a complete absence of recombination is rare, it has been reported for some species, among them 2 extremotolerant black yeasts from Dothideomycetes: Hortaea werneckii and Aureobasidium melanogenum. Therefore, the presence of diploid strains in these species cannot be explained as the product of conventional sexual reproduction. RESULTS Genome sequencing revealed that the ratio of diploid to haploid strains in both H. werneckii and A. melanogenum is about 2:1. Linkage disequilibrium between pairs of polymorphic loci and a high degree of concordance between the phylogenies of different genomic regions confirmed that both species are clonal. Heterozygosity of diploid strains is high, with several hybridizing genome pairs reaching the intergenomic distances typically seen between different fungal species. The origin of diploid strains collected worldwide can be traced to a handful of hybridization events that produced diploids, which were stable over long periods of time and distributed over large geographic areas. CONCLUSIONS Our results, based on the genomes of over 100 strains of 2 black yeasts, show that although they are clonal, they occasionally form stable and highly heterozygous diploid intraspecific hybrids. The mechanism of these apparently rare hybridization events, which are not followed by meiosis or haploidization, remains unknown. Both extremotolerant yeasts, H. werneckii and even more so A. melanogenum, a close relative of the intensely recombining and biotechnologically relevant Aureobasidium pullulans, provide an attractive model for studying the role of clonality and ploidy in extremotolerant fungi.
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Affiliation(s)
- Cene Gostinčar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
- Lars Bolund Institute of Regenerative Medicine, BGI-Qingdao, Qingdao 266555, China
| | - Xiaohuan Sun
- BGI-Shenzhen, Beishan Industrial Zone, Shenzhen 518083, China
| | - Anja Černoša
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Chao Fang
- BGI-Shenzhen, Beishan Industrial Zone, Shenzhen 518083, China
| | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Zewei Song
- BGI-Shenzhen, Beishan Industrial Zone, Shenzhen 518083, China
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6
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Muggia L, Coleine C, De Carolis R, Cometto A, Selbmann L. Antarctolichenia onofrii gen. nov. sp. nov. from Antarctic Endolithic Communities Untangles the Evolution of Rock-Inhabiting and Lichenized Fungi in Arthoniomycetes. J Fungi (Basel) 2021; 7:935. [PMID: 34829222 PMCID: PMC8621061 DOI: 10.3390/jof7110935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/20/2021] [Accepted: 10/23/2021] [Indexed: 11/25/2022] Open
Abstract
Microbial endolithic communities are the main and most widespread life forms in the coldest and hyper-arid desert of the McMurdo Dry Valleys and other ice-free areas across Victoria Land, Antarctica. There, the lichen-dominated communities are complex and self-supporting assemblages of phototrophic and heterotrophic microorganisms, including bacteria, chlorophytes, and both free-living and lichen-forming fungi living at the edge of their physiological adaptability. In particular, among the free-living fungi, microcolonial, melanized, and anamorphic species are highly recurrent, while a few species were sometimes found to be associated with algae. One of these fungi is of paramount importance for its peculiar traits, i.e., a yeast-like habitus, co-growing with algae and being difficult to propagate in pure culture. In the present study, this taxon is herein described as the new genus Antarctolichenia and its type species is A. onofrii, which represents a transitional group between the free-living and symbiotic lifestyle in Arthoniomycetes. The phylogenetic placement of Antarctolichenia was studied using three rDNA molecular markers and morphological characters were described. In this study, we also reappraise the evolution and the connections linking the lichen-forming and rock-inhabiting lifestyles in the basal lineages of Arthoniomycetes (i.e., Lichenostigmatales) and Dothideomycetes.
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Affiliation(s)
- Lucia Muggia
- Department of Life Sciences, University of Trieste, Via Giorgieri 10, 34127 Trieste, Italy; (L.M.); (R.D.C.); (A.C.)
| | - Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’ Università, 01100 Viterbo, Italy;
| | - Roberto De Carolis
- Department of Life Sciences, University of Trieste, Via Giorgieri 10, 34127 Trieste, Italy; (L.M.); (R.D.C.); (A.C.)
| | - Agnese Cometto
- Department of Life Sciences, University of Trieste, Via Giorgieri 10, 34127 Trieste, Italy; (L.M.); (R.D.C.); (A.C.)
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’ Università, 01100 Viterbo, Italy;
- Mycological Section, Italian Antarctic National Museum (MNA), 16128 Genoa, Italy
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7
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Polle JE, Jin E, Ben-Amotz A. The alga Dunaliella revisited: Looking back and moving forward with model and production organisms. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101948] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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8
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Muggia L, Zalar P, Azua-Bustos A, González-Silva C, Grube M, Gunde-Cimerman N. The beauty and the yeast: can the microalgae Dunaliella form a borderline lichen with Hortaea werneckii? Symbiosis 2020; 82:123-131. [PMID: 33536700 PMCID: PMC7116670 DOI: 10.1007/s13199-020-00697-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Lichenized fungi usually develop complex, stratified morphologies through an intricately balanced living together with their algal partners, but several species are known to form only more or less loose associations with algae. These borderline lichens are still little explored although they could inform us about early stages of lichen evolution. We studied the association of the extremely halotolerant fungus Hortaea werneckii with the alga Dunaliella atacamensis, discovered in a cave in the Atacama Desert (Chile), and with D. salina, common inhabitant of saltern brines. D. atacamensis forms small colonies, in which cells of H. werneckii can be frequently observed, while such interaction has not been observed with D. salina. As symbiotic interactions between Dunaliella and Hortaea have not been reported, we performed a series of co-cultivation experiments to inspect whether these species could interact and develop more distinct lichen-like symbiotic structures. We set up co-cultures between axenic strains of Hortaea werneckii (isolated both from Mediterranean salterns and from the Atacama cave) and isolates of D. atacamensis (from the Atacama cave) and D. salina (isolated from Mediterranean salterns). Although we used different growth media and cultivation approaches, bright field and SEM microscopy analyses did not indicate any mutual effects in these experiments. We discuss the implications for fungal algal interactions along the transition from algal exploiters to lichen symbioses.
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Affiliation(s)
- Lucia Muggia
- Department of Life Sciences, University of Trieste, via Giorgieri 10, 34127 Trieste, Italy
| | - Polona Zalar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večnapot 111, 1000 Ljubljana, Slovenia
| | - Armando Azua-Bustos
- Centro de Astrobiología (CSIC-INTA), 28850 Madrid, Torrejón de Ardoz, Spain.,Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, 8910060 Santiago, Chile
| | | | - Martin Grube
- University of Graz, Institute of Biology, Holteigasse 6, 8010 Graz, Austria
| | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večnapot 111, 1000 Ljubljana, Slovenia
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9
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Zalar P, Zupančič J, Gostinčar C, Zajc J, de Hoog GS, De Leo F, Azua-Bustos A, Gunde-Cimerman N. The extremely halotolerant black yeast Hortaea werneckii - a model for intraspecific hybridization in clonal fungi. IMA Fungus 2019; 10:10. [PMID: 32647617 PMCID: PMC7325687 DOI: 10.1186/s43008-019-0007-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 04/03/2019] [Indexed: 12/22/2022] Open
Abstract
The polymorphic black yeast Hortaea werneckii (Capnodiales, Ascomycota) is extremely halotolerant (growth from 0 to 30% [w/v] NaCl) and has been extensively studied as a model for halotolerance in Eukaryotes for over two decades. Its most frequent sources are hypersaline environments and adjacent sea-water habitats in temperate, subtropical and tropical climates. Although typically saprobic, H. werneckii can also act as a commensal coloniser on human skin, causing tinea nigra on hands and soles. Here, we report that addition of NaCl to culture media expands the growth range of H. werneckii to 37 °C, which explains its colonisation of human skin, with its increased salinity. The morphological and physiological plasticity/ versatility of H. werneckii indicate that a species complex might be involved. This was investigated in this polyphasic taxonomic analysis based on the global diversity of H. werneckii strains collected from hypersaline environments, and from humans and animals. Analysis of D1/D2domains of 28S and internal transcribed spacer rDNA revealed 10 and 17 genotypes, respectively, that were not always compliant. The genotypes have global distributions. Human and environmental strains with the same genotypes are intermingled. Due to the limited number of phylogenetically informative characters in the ribosomal DNA dataset, the partial genes encoding for β-tubulin (BTB) and mini-chromosome maintenance protein (MCM7) were also sequenced. The use of these genes was hampered by ambiguous sequences obtained by Sanger sequencing, as a consequence of the diploid and highly heterozygous genome of many H. werneckii strains. Analysis of the BTB and MCM7 genes showed that in some cases two copies of the gene from the same genome are positioned in distant phylogenetic clusters of the intraspecific gene tree. Analysis of whole-genome sequences of selected H. werneckii strains generally confirmed the phylogenetic distances estimated on the basis of ribosomal genes, but also showed substantial reticulation within the phylogenetic history of the strains. This is in line with the hypothesis that the diploid genomes of H. werneckii were formed by hybridizations, which have sometimes occurred between relatively divergent strains.
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Affiliation(s)
- Polona Zalar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, Slovenia
| | - Jerneja Zupančič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, Slovenia
| | - Cene Gostinčar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, Slovenia
- Lars Bolund Institute of Regenerative Medicine, BGI-Qingdao, Qingdao, 266555 China
| | - Janja Zajc
- Department of Biotechnology and Systems Biology, National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia
| | - G. Sybren de Hoog
- Westerdijk Fungal Biodiversity Institute, P.O. Box 85167, Utrecht, 3508 AD The Netherlands
- Centre of Expertise in Mycology of RadboudUMC, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Filomena De Leo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences (ChiBioFarAm), University of Messina, Viale F. Stagno d’Alcontres, 31 98166 Messina, Italy
| | - Armando Azua-Bustos
- Centro de Astrobiología (CSIC-INTA), Madrid, Spain
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, 8910060 Santiago, Chile
| | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, Slovenia
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10
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Azua-Bustos A, Fairén AG, González-Silva C, Ascaso C, Carrizo D, Fernández-Martínez MÁ, Fernández-Sampedro M, García-Descalzo L, García-Villadangos M, Martin-Redondo MP, Sánchez-García L, Wierzchos J, Parro V. Unprecedented rains decimate surface microbial communities in the hyperarid core of the Atacama Desert. Sci Rep 2018; 8:16706. [PMID: 30420604 PMCID: PMC6232106 DOI: 10.1038/s41598-018-35051-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/30/2018] [Indexed: 11/09/2022] Open
Abstract
The hyperarid core of the Atacama Desert, the driest and oldest desert on Earth, has experienced a number of highly unusual rain events over the past three years, resulting in the formation of previously unrecorded hypersaline lagoons, which have lasted several months. We have systematically analyzed the evolution of the lagoons to provide quantitative field constraints of large-scale impacts of the rains on the local microbial communities. Here we show that the sudden and massive input of water in regions that have remained hyperarid for millions of years is harmful for most of the surface soil microbial species, which are exquisitely adapted to survive with meager amounts of liquid water, and quickly perish from osmotic shock when water becomes suddenly abundant. We found that only a handful of bacteria, remarkably a newly identified species of Halomonas, remain metabolically active and are still able to reproduce in the lagoons, while no archaea or eukaryotes were identified. Our results show that the already low microbial biodiversity of extreme arid regions greatly diminishes when water is supplied quickly and in great volumes. We conclude placing our findings in the context of the astrobiological exploration of Mars, a hyperarid planet that experienced catastrophic floodings in ancient times.
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Affiliation(s)
- A Azua-Bustos
- Centro de Astrobiología (CSIC-INTA), 28850, Madrid, Spain. .,Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile.
| | - A G Fairén
- Centro de Astrobiología (CSIC-INTA), 28850, Madrid, Spain. .,Department of Astronomy, Cornell University, Ithaca, 14853, NY, USA.
| | | | - C Ascaso
- Museo Nacional de Ciencias Naturales (CSIC), 28006, Madrid, Spain
| | - D Carrizo
- Centro de Astrobiología (CSIC-INTA), 28850, Madrid, Spain
| | | | | | | | | | | | | | - J Wierzchos
- Museo Nacional de Ciencias Naturales (CSIC), 28006, Madrid, Spain
| | - V Parro
- Centro de Astrobiología (CSIC-INTA), 28850, Madrid, Spain
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11
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Henley WJ, Cobbs M, Novoveská L, Buchheim MA. Phylogenetic analysis of Dunaliella (Chlorophyta) emphasizing new benthic and supralittoral isolates from Great Salt Lake. JOURNAL OF PHYCOLOGY 2018; 54:483-493. [PMID: 29679512 DOI: 10.1111/jpy.12747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 04/05/2018] [Indexed: 06/08/2023]
Abstract
Dunaliella, a commercially important chlorophyte, is globally distributed in saline habitats. Morphological species have not been definitively reconciled with phylogenetic analyses. Considerable genetic diversity continues to be discovered in new isolates, especially from soil and benthic habitats. Twenty-nine new isolates from Great Salt Lake, Utah, many from benthic or supralittoral habitats, were phylogenetically analyzed using ITS1+5.8S+ITS2 in comparison to a broad sampling of available sequences. A few new isolates align in one branch of a bifurcated monophyletic Dunaliella salina clade and several cluster within monophyletic D. viridis. Several others align with relatively few unnamed strains from other locations, comprising a diverse clade that may represent two or more new species. The overall Dunaliella clade is relatively robust, but the nearest outgroups are ambiguously placed with extremely long branches. About half of the isolates, all from benthic or supralittoral habitats, have been persistently sarcinoid in liquid media since isolation. This trait is spread across the Dunaliella phylogeny. The morphology of two sarcinoid strains was documented with light microscopy, revealing an extensive glycocalyx. Clumping behavior of unicellular and sarcinoid strains was unaffected by presence or absence of Mg2+ or Ca2+ , addition of lectin-inhibiting monosaccharides, or water-soluble factors from morphologically opposite strains. Results from this investigation have significantly expanded our current understanding of Dunaliella diversity, but it seems likely that much remains to be discovered with additional sampling.
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Affiliation(s)
- William J Henley
- Department of Plant Biology, Ecology and Evolution, Oklahoma State University, Stillwater, Oklahoma, 74078, USA
| | - Michael Cobbs
- Department of Plant Biology, Ecology and Evolution, Oklahoma State University, Stillwater, Oklahoma, 74078, USA
| | - Lucie Novoveská
- Department of Plant Biology, Ecology and Evolution, Oklahoma State University, Stillwater, Oklahoma, 74078, USA
| | - Mark A Buchheim
- Department of Biological Science, The University of Tulsa, Tulsa, Oklahoma, 74104, USA
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12
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Bull AT, Asenjo JA, Goodfellow M, Gómez-Silva B. The Atacama Desert: Technical Resources and the Growing Importance of Novel Microbial Diversity. Annu Rev Microbiol 2017; 70:215-34. [PMID: 27607552 DOI: 10.1146/annurev-micro-102215-095236] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Atacama Desert of northern Chile is the oldest and most arid nonpolar environment on Earth. It is a coastal desert covering approximately 180,000 km(2), and together with the greater Atacama region it comprises a dramatically wide range of ecological niches. Long known and exploited for its mineral resources, the Atacama Desert harbors a rich microbial diversity that has only recently been discovered; the great majority of it has not yet been recovered in culture or even taxonomically identified. This review traces the progress of microbiology research in the Atacama and dispels the popular view that this region is virtually devoid of life. We examine reasons for such research activity and demonstrate that microbial life is the latest recognized and least explored resource in this inspiring biome.
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Affiliation(s)
- Alan T Bull
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom;
| | - Juan A Asenjo
- Center for Biotechnology and Bioengineering, University of Chile, Santiago, Chile.,Department of Chemical Engineering and Biotechnology, University of Chile, Santiago, Chile;
| | - Michael Goodfellow
- School of Biology, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom;
| | - Benito Gómez-Silva
- Biochemistry Laboratory, Biomedical Department, Faculty of Health Sciences, University of Antofagasta, Chile;
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13
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14
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Azua-Bustos A, González-Silva C, Corsini G. The Hyperarid Core of the Atacama Desert, an Extremely Dry and Carbon Deprived Habitat of Potential Interest for the Field of Carbon Science. Front Microbiol 2017. [PMID: 28642741 PMCID: PMC5463503 DOI: 10.3389/fmicb.2017.00993] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The Atacama Desert in Chile is the driest and oldest desert on Earth, also considered one of the best Mars analog models. Here, several heterotrophic microbial communities have been discovered in its driest regions, with the ones present in the soil subsurface being one of the most interesting due to its existence in a habitat with almost no water available and almost undetectable organic carbon sources. Our recent discovery of the driest site of the Atacama known to date (and the heterotrophic microbial species that are able to survive in this site) reaffirms the opportunity to better characterize the physiological and molecular mechanisms that these species use to detect, mobilize, incorporate and use carbon under these extremely harsh conditions. Here we summarize what has been reported up to date on the organic carbon concentrations in different sites of the hyperarid core of the Atacama Desert, proposing that due to the meager amounts of carbon and extremely dry conditions, the microbial communities of the hyperarid core of the Atacama Desert may be of interest for the field of carbon science.
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Affiliation(s)
- Armando Azua-Bustos
- Centro de Astrobiología (Consejo Superior de Investigaciones Científicas-Instituto Nacional de Técnica Aeroespacial)Madrid, Spain.,Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de ChileSantiago, Chile
| | | | - Gino Corsini
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de ChileSantiago, Chile
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15
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Aspergillus atacamensis and A. salisburgensis: two new halophilic species from hypersaline/arid habitats with a phialosimplex-like morphology. Extremophiles 2017; 21:755-773. [PMID: 28500388 DOI: 10.1007/s00792-017-0941-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/29/2017] [Indexed: 01/11/2023]
Abstract
Halophilic fungal strains isolated from historical wooden staircase in a salt mine in Austria, and from wall biofilm and soil of a cave in the Coastal Range of the hyperarid Atacama Desert in Chile were characterised and described newly as Aspergillus salisburgensis and Aspergillus atacamensis. Morphological characters including solitary phialides producing solitary conidia and conidia in chains and/or heads suggested affinity to Aspergillus subgenus Polypaecilum. Strains required salt for growth, grew optimally on media with 10-25% NaCl and at 15-28 °C. These values are similar to those observed for Aspergillus salinarus comb. nov. (Phialosimplex salinarum), while the ex-type strains of Aspergillus sclerotialis, Aspergillus chlamydosporus and Aspergillus caninus (all belonging to Aspergillus subgen. Polypaecilum) grew optimally at 0-5% NaCl and showed fastest growth at 28-37 °C. Phylogenetic analyses on the basis of rDNA sequences, RAPD-PCR fingerprint patterns, and cellobiohydrolase gene (cbh-I) polymorphism clustered the strains into three groups and supported their taxonomic recognition as A. salinarus, A. atacamensis and A. salisburgensis. On the basis of phylogenetic inferences, also Sagenomella keratitidis is newly combined as Aspergillus keratitidis and inferred as a species of Aspergillus subgenus Polypaecilum.
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16
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Stevenson A, Cray JA, Williams JP, Santos R, Sahay R, Neuenkirchen N, McClure CD, Grant IR, Houghton JDR, Quinn JP, Timson DJ, Patil SV, Singhal RS, Antón J, Dijksterhuis J, Hocking AD, Lievens B, Rangel DEN, Voytek MA, Gunde-Cimerman N, Oren A, Timmis KN, McGenity TJ, Hallsworth JE. Is there a common water-activity limit for the three domains of life? THE ISME JOURNAL 2015; 9:1333-51. [PMID: 25500507 PMCID: PMC4438321 DOI: 10.1038/ismej.2014.219] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/07/2014] [Accepted: 10/16/2014] [Indexed: 01/09/2023]
Abstract
Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (a(w)) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650-0.605 a(w). Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 a(w)). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 aw for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 a(w) for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life.
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Affiliation(s)
- Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Jonathan A Cray
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Jim P Williams
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Ricardo Santos
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
- Laboratório de Análises, Instituto Superior Técnico, Lisboa, Portugal
| | - Richa Sahay
- University of Essex, School of Biological Sciences, Colchester, Essex, UK
| | - Nils Neuenkirchen
- University of Essex, School of Biological Sciences, Colchester, Essex, UK
| | - Colin D McClure
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Irene R Grant
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Jonathan DR Houghton
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - John P Quinn
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - David J Timson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Satish V Patil
- School of Life Sciences, North Maharashtra University, Jalgaon, Maharashtra, India
| | - Rekha S Singhal
- Department of Food Engineering and Technology, Institute of Chemical Technology, Mumbai, India
| | - Josefa Antón
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | | | - Ailsa D Hocking
- CSIRO Food and Nutrition, North Ryde, New South Wales, Australia
| | - Bart Lievens
- Microbial Ecology and Biorational Control, Scientia Terrae Research Institute, Sint-Katelijne-Waver, Belgium
| | - Drauzio E N Rangel
- Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, São Paulo, Brazil
| | | | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Aharon Oren
- Hebrew University of Jerusalem, Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Jerusalem, Israel
| | - Kenneth N Timmis
- University of Essex, School of Biological Sciences, Colchester, Essex, UK
- Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany
| | - Terry J McGenity
- University of Essex, School of Biological Sciences, Colchester, Essex, UK
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, Northern Ireland, UK
- University of Essex, School of Biological Sciences, Colchester, Essex, UK
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17
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Azua-Bustos A, Caro-Lara L, Vicuña R. Discovery and microbial content of the driest site of the hyperarid Atacama Desert, Chile. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:388-94. [PMID: 25545388 DOI: 10.1111/1758-2229.12261] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 12/02/2014] [Accepted: 12/08/2014] [Indexed: 05/27/2023]
Abstract
The Atacama Desert is the driest and oldest desert on Earth. Eleven years ago, the Yungay region was established as the driest site of this hyperarid desert and also close to the dry limit for life on Earth. Since then, much has been published about the extraordinary characteristics of this site and its pertinence as a Mars analogue model. However, as a result of a more systematic search in the Atacama here, we describe a new site, María Elena South (MES), which is much drier than Yungay. The mean atmospheric relative humidity (RH) at MES was 17.3%, with the RH of its soils remaining at a constant 14% at the depth of 1 m, a value that matches the lowest RH measurements taken by the Mars Science Laboratory at Gale Crater. Remarkably, we found a number of viable bacterial species in the soil profile at MES using a combination of molecular dependent and independent methods, unveiling the presence of life in the driest place on the Atacama Desert reported to date.
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Affiliation(s)
- Armando Azua-Bustos
- Faculty of Biological Sciences, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Investigación Biomédica, Universidad Autónoma de Chile, Santiago, Chile
| | | | - Rafael Vicuña
- Faculty of Biological Sciences, Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago, Chile
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18
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Oren A. The ecology of Dunaliella in high-salt environments. ACTA ACUST UNITED AC 2014; 21:23. [PMID: 25984505 PMCID: PMC4389652 DOI: 10.1186/s40709-014-0023-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 11/26/2014] [Indexed: 01/26/2023]
Abstract
Halophilic representatives of the genus Dunaliella, notably D. salina and D. viridis, are found worldwide in salt lakes and saltern evaporation and crystallizer ponds at salt concentrations up to NaCl saturation. Thanks to the biotechnological exploitation of D. salina for β-carotene production we have a profound knowledge of the physiology and biochemistry of the alga. However, relatively little is known about the ecology of the members of the genus Dunaliella in hypersaline environments, in spite of the fact that Dunaliella is often the main or even the sole primary producer present, so that the entire ecosystem depends on carbon fixed by this alga. This review paper summarizes our knowledge about the occurrence and the activities of different Dunaliella species in natural salt lakes (Great Salt Lake, the Dead Sea and others), in saltern ponds and in other salty habitats where members of the genus have been found.
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Affiliation(s)
- Aharon Oren
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 91904 Israel
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19
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Biotechnological applications derived from microorganisms of the Atacama Desert. BIOMED RESEARCH INTERNATIONAL 2014; 2014:909312. [PMID: 25147824 PMCID: PMC4132489 DOI: 10.1155/2014/909312] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/29/2014] [Accepted: 07/07/2014] [Indexed: 01/18/2023]
Abstract
The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development.
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20
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Robinson CK, Wierzchos J, Black C, Crits-Christoph A, Ma B, Ravel J, Ascaso C, Artieda O, Valea S, Roldán M, Gómez-Silva B, DiRuggiero J. Microbial diversity and the presence of algae in halite endolithic communities are correlated to atmospheric moisture in the hyper-arid zone of the Atacama Desert. Environ Microbiol 2014; 17:299-315. [PMID: 24372972 DOI: 10.1111/1462-2920.12364] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 12/11/2013] [Accepted: 12/17/2013] [Indexed: 11/26/2022]
Abstract
The Atacama Desert is one of the oldest and driest deserts in the world, and its hyper-arid core is described as 'the most barren region imaginable'. We used a combination of high-throughput sequencing and microscopy methods to characterize the endolithic microbial assemblages of halite pinnacles (salt rocks) collected in several hyper-arid areas of the desert. We found communities dominated by archaea that relied on a single phylotype of Halothece cyanobacteria for primary production. A few other phylotypes of salt-adapted bacteria and archaea, including Salinibacter, Halorhabdus, and Halococcus were major components of the halite communities, indicating specific adaptations to the unique halite environments. Multivariate statistical analyses of diversity metrics clearly separated the halite communities from that of the surrounding soil in the Yungay area. These analyses also revealed distribution patterns of halite communities correlated with atmospheric moisture. Microbial endolithic communities from halites exposed to coastal fogs and high relative humidity were more diverse; their archaeal and bacterial assemblages were accompanied by a novel algae related to oceanic picoplankton of the Mamiellales. In contrast, we did not find any algae in the Yungay pinnacles, suggesting that the environmental conditions in this habitat might be too extreme for eukaryotic photosynthetic life.
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Holzinger A, Karsten U. Desiccation stress and tolerance in green algae: consequences for ultrastructure, physiological and molecular mechanisms. FRONTIERS IN PLANT SCIENCE 2013; 4:327. [PMID: 23986769 PMCID: PMC3749462 DOI: 10.3389/fpls.2013.00327] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 08/02/2013] [Indexed: 05/18/2023]
Abstract
Although most green algae typically occur in aquatic ecosystems, many species also live partly or permanently under aeroterrestrial conditions, where the cells are exposed to the atmosphere and hence regularly experience dehydration. The ability of algal cells to survive in an air-dried state is termed desiccation tolerance. The mechanisms involved in desiccation tolerance of green algae are still poorly understood, and hence the aim of this review is to summarize recent findings on the effects of desiccation and osmotic water loss. Starting from structural changes, physiological, and biochemical consequences of desiccation will be addressed in different green-algal lineages. The available data clearly indicate a range of strategies, which are rather different in streptophycean and non-streptophycean green algae. While members of the Trebouxiophyceae exhibit effective water loss-prevention mechanisms based on the biosynthesis and accumulation of particular organic osmolytes such as polyols, these compounds are so far not reported in representatives of the Streptophyta. In members of the Streptophyta such as Klebsormidium, the most striking observation is the appearance of cross-walls in desiccated samples, which are strongly undulating, suggesting a high degree of mechanical flexibility. This aids in maintaining structural integrity in the dried state and allows the cell to maintain turgor pressure for a prolonged period of time during the dehydration process. Physiological strategies in aeroterrestrial green algae generally include a rapid reduction of photosynthesis during desiccation, but also a rather quick recovery after rewetting, whereas aquatic species are sensitive to drying. The underlying mechanisms such as the affected molecular components of the photosynthetic machinery are poorly understood in green algae. Therefore, modern approaches based on transcriptomics, proteomics, and/or metabolomics are urgently needed to better understand the molecular mechanisms involved in desiccation-stress physiology of these organisms. The very limited existing information is described in the present review.
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Affiliation(s)
- Andreas Holzinger
- Functional Plant Biology, Institute of Botany, University of InnsbruckInnsbruck, Austria
| | - Ulf Karsten
- Applied Ecology and Phycology, Institute of Biological Sciences, University of RostockRostock, Germany
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22
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Goo BG, Baek G, Choi DJ, Park YI, Synytsya A, Bleha R, Seong DH, Lee CG, Park JK. Characterization of a renewable extracellular polysaccharide from defatted microalgae Dunaliella tertiolecta. BIORESOURCE TECHNOLOGY 2013; 129:343-50. [PMID: 23262010 DOI: 10.1016/j.biortech.2012.11.077] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 11/12/2012] [Accepted: 11/19/2012] [Indexed: 05/10/2023]
Abstract
Extracellular polysaccharide (EPS) was isolated from defatted micro-algae Dunaliela tertiolecta and defined as linear (1→4)-α-D-glucan based on monosaccharide composition, enzymatic and spectroscopic analyses. Optimization and characterization of acidic and enzymatic hydrolyses of EPS have been performed for its potential use as a renewable biorefinery material. The hydrolytic methods were improved to assess the effect of substrate specificity, reaction time, pH, ionic strength and temperature on efficiency of glucose production. EPS was effectively converted into glucose within one-step enzymatic or acidic hydrolysis under optimized conditions. Over 90% recovery of glucose was achieved for both hydrolytic approaches. High potential production of EPS and high yield conversion of this substrate to glucose may allow further exploration of microalga D. tertiolecta as a potential biomass producer for biotechnological and industrial exploitation of bioethanol.
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Affiliation(s)
- Bon Geun Goo
- Department of Biotechnology, The Catholic University of Korea, Bucheon 420-743, Republic of Korea
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23
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Holzinger A, Karsten U. Desiccation stress and tolerance in green algae: consequences for ultrastructure, physiological and molecular mechanisms. FRONTIERS IN PLANT SCIENCE 2013. [PMID: 23986769 DOI: 10.3389/fpls.2013.0327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Although most green algae typically occur in aquatic ecosystems, many species also live partly or permanently under aeroterrestrial conditions, where the cells are exposed to the atmosphere and hence regularly experience dehydration. The ability of algal cells to survive in an air-dried state is termed desiccation tolerance. The mechanisms involved in desiccation tolerance of green algae are still poorly understood, and hence the aim of this review is to summarize recent findings on the effects of desiccation and osmotic water loss. Starting from structural changes, physiological, and biochemical consequences of desiccation will be addressed in different green-algal lineages. The available data clearly indicate a range of strategies, which are rather different in streptophycean and non-streptophycean green algae. While members of the Trebouxiophyceae exhibit effective water loss-prevention mechanisms based on the biosynthesis and accumulation of particular organic osmolytes such as polyols, these compounds are so far not reported in representatives of the Streptophyta. In members of the Streptophyta such as Klebsormidium, the most striking observation is the appearance of cross-walls in desiccated samples, which are strongly undulating, suggesting a high degree of mechanical flexibility. This aids in maintaining structural integrity in the dried state and allows the cell to maintain turgor pressure for a prolonged period of time during the dehydration process. Physiological strategies in aeroterrestrial green algae generally include a rapid reduction of photosynthesis during desiccation, but also a rather quick recovery after rewetting, whereas aquatic species are sensitive to drying. The underlying mechanisms such as the affected molecular components of the photosynthetic machinery are poorly understood in green algae. Therefore, modern approaches based on transcriptomics, proteomics, and/or metabolomics are urgently needed to better understand the molecular mechanisms involved in desiccation-stress physiology of these organisms. The very limited existing information is described in the present review.
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Affiliation(s)
- Andreas Holzinger
- Functional Plant Biology, Institute of Botany, University of Innsbruck Innsbruck, Austria
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Azua-Bustos A, González-Silva C, Arenas-Fajardo C, Vicuña R. Extreme environments as potential drivers of convergent evolution by exaptation: the Atacama Desert Coastal Range case. Front Microbiol 2012; 3:426. [PMID: 23267354 PMCID: PMC3526103 DOI: 10.3389/fmicb.2012.00426] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 12/03/2012] [Indexed: 11/13/2022] Open
Abstract
We have recently discovered a variety of unrelated phototrophic microorganisms (two microalgae and one cyanobacteria) in specialized terrestrial habitats at The Coastal Range of the Atacama Desert. Interestingly, morphological and molecular evidence suggest that these three species are all recent colonists that came from aquatic habitats. The first case is Cyanidiales inhabiting coastal caves. Cyanidiales are microalgae that are commonly found in warm acid springs, but have also been recently discovered as cave flora in Italy. The case is Dunaliella biofilms colonizing spider webs in coastal caves; Dunaliella are microalgae typically found in hypersaline habitats. The third case is Chroococcidiopsis, a genus of Cyanobacteria commonly found in deserts around the world that has also been described in warm springs. Thus, we show that the traits found in the closest ancestors of the aforementioned species (which inhabited other unrelated extreme environments) seem to be now useful for the described species in their current subaerial habitats and may likely correspond to cases of exaptations. Altogether, the Coastal Range of the Atacama Desert may be considered as a place where key steps on the colonization of land by phototrophic organisms seem to be being repeated by convergent evolution of extant microalgae and Cyanobacteria.
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Affiliation(s)
- Armando Azua-Bustos
- Department of Molecular Genetics and Microbiology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | | | - Cristián Arenas-Fajardo
- Department of Molecular Genetics and Microbiology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Rafael Vicuña
- Department of Molecular Genetics and Microbiology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
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Preetha K, John L, Subin CS, Vijayan KK. Phenotypic and genetic characterization of Dunaliella (Chlorophyta) from Indian salinas and their diversity. AQUATIC BIOSYSTEMS 2012; 8:27. [PMID: 23114277 PMCID: PMC3598838 DOI: 10.1186/2046-9063-8-27] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 10/16/2012] [Indexed: 05/08/2023]
Abstract
BACKGROUND The genus Dunaliella (Class - Chlorophyceae) is widely studied for its tolerance to extreme habitat conditions, physiological aspects and many biotechnological applications, such as a source of carotenoids and many other bioactive compounds. Biochemical and molecular characterization is very much essential to fully explore the properties and possibilities of the new isolates of Dunaliella. In India, hyper saline lakes and salt pans were reported to bloom with Dunaliella spp. However, except for the economically important D. salina, other species are rarely characterized taxonomically from India. Present study was conducted to describe Dunaliella strains from Indian salinas using a combined morphological, physiological and molecular approach with an aim to have a better understanding on the taxonomy and diversity of this genus from India. RESULTS Comparative phenotypic and genetic studies revealed high level of diversity within the Indian Dunaliella isolates. Species level identification using morphological characteristics clearly delineated two strains of D. salina with considerable β-carotene content (>20 pg/cell). The variation in 18S rRNA gene size, amplified with MA1-MA2 primers, ranged between ~1800 and ~2650 base pairs, and together with the phylogeny based on ITS gene sequence provided a pattern, forming five different groups within Indian Dunaliella isolates. Superficial congruency was observed between ITS and rbcL gene phylogenetic trees with consistent formation of major clades separating Indian isolates into two distinct clusters, one with D. salina and allied strains, and another one with D. viridis and allied strains. Further in both the trees, few isolates showed high level of genetic divergence than reported previously for Dunaliella spp. This indicates the scope of more numbers of clearly defined/unidentified species/sub-species within Indian Dunaliella isolates. CONCLUSION Present work illustrates Indian Dunaliella strains phenotypically and genetically, and confirms the presence of not less than five different species (or sub-species) in Indian saline waters, including D. salina and D. viridis. The study emphasizes the need for a combined morphological, physiological and molecular approach in the taxonomic studies of Dunaliella.
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Affiliation(s)
- Krishna Preetha
- Genetics and Genomics Section, Marine Biotechnology Division, Central Marine Fisheries Research Institute, Post Box No. 1603, Ernakulam North P.O, Kochi, 682018, India
| | - Lijo John
- Genetics and Genomics Section, Marine Biotechnology Division, Central Marine Fisheries Research Institute, Post Box No. 1603, Ernakulam North P.O, Kochi, 682018, India
| | - Cherampillil Sukumaran Subin
- Genetics and Genomics Section, Marine Biotechnology Division, Central Marine Fisheries Research Institute, Post Box No. 1603, Ernakulam North P.O, Kochi, 682018, India
| | - Koyadan Kizhakkedath Vijayan
- Genetics and Genomics Section, Marine Biotechnology Division, Central Marine Fisheries Research Institute, Post Box No. 1603, Ernakulam North P.O, Kochi, 682018, India
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Azua-Bustos A, Urrejola C, Vicuña R. Life at the dry edge: microorganisms of the Atacama Desert. FEBS Lett 2012; 586:2939-45. [PMID: 22819826 DOI: 10.1016/j.febslet.2012.07.025] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 07/10/2012] [Accepted: 07/11/2012] [Indexed: 11/29/2022]
Abstract
The Atacama Desert, located in northern Chile, is the driest and oldest desert on Earth. Research aimed at the understanding of this unique habitat and its diverse microbial ecosystems begun only a few decades ago, mainly driven by NASA's astrobiology program. A milestone in these efforts was a paper published in 2003, when the Atacama was shown to be a proper model of Mars. From then on, studies have been focused to examine every possible niche suitable for microbial life in this extreme environment. Habitats as different as the underside of quartz rocks, fumaroles at the Andes Mountains, the inside of halite evaporates and caves of the Coastal Range, among others, have shown that life has found ingenious ways to adapt to extreme conditions such as low water availability, high salt concentration and intense UV radiation.
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Affiliation(s)
- Armando Azua-Bustos
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Chile
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Govender T, Ramanna L, Rawat I, Bux F. BODIPY staining, an alternative to the Nile Red fluorescence method for the evaluation of intracellular lipids in microalgae. BIORESOURCE TECHNOLOGY 2012; 114:507-11. [PMID: 22464420 DOI: 10.1016/j.biortech.2012.03.024] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 02/15/2012] [Accepted: 03/07/2012] [Indexed: 05/03/2023]
Abstract
In order to develop feasible production processes for microalgal biodiesel, the isolation of high neutral lipid producing microalgae is crucial. Since the established Nile Red (NR) method for detection of intracellular lipids has been successful only for some microalgae, a more broadly applicable detection method would be desirable. Therefore, BODIPY 505/515, a lipophilic bright green fluorescent dye was tested for detection of intracellular lipids in Chlorella vulgaris, Dunaliella primolecta and Chaetoceros calcitrans. An optimum concentration of 0.067 μg ml(-1) was determined for lipid staining in the microalgae. Compared to NR, BODIPY 505/515 was more effective in staining microalgae and showed resistance to photobleaching, maintaining its fluorescence longer than 30 min.
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Affiliation(s)
- T Govender
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4001, South Africa
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Gostinčar C, Lenassi M, Gunde-Cimerman N, Plemenitaš A. Fungal adaptation to extremely high salt concentrations. ADVANCES IN APPLIED MICROBIOLOGY 2011; 77:71-96. [PMID: 22050822 DOI: 10.1016/b978-0-12-387044-5.00003-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hypersaline environments support substantial microbial communities of selected halotolerant and halophilic organisms, including fungi from various orders. In hypersaline water of solar salterns, the black yeast Hortaea werneckii is by far the most successful fungal representative. It has an outstanding ability to overcome the turgor loss and sodium toxicity that are typical for hypersaline environments, which facilitates its growth even in solutions that are almost saturated with NaCl. We propose a model of cellular responses to high salt concentrations that integrates the current knowledge of H. werneckii adaptations. The negative impact of a hyperosmolar environment is counteracted by an increase in the energy supply that is needed to drive the energy-demanding export of ions and synthesis of compatible solutes. Changes in membrane lipid composition and cell-wall structure maintain the integrity and functioning of the stressed cells. Understanding the salt responses of H. werneckii and other fungi (e.g., the halophilic Wallemia ichthyophaga) will extend our knowledge of fungal stress tolerance and promote the use of the currently unexploited biotechnological potential of fungi that live in hypersaline environments.
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