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Canini F, Borruso L, Newsham KK, D'Alò F, D'Acqui LP, Zucconi L. Wide divergence of fungal communities inhabiting rocks and soils in a hyper-arid Antarctic desert. Environ Microbiol 2023; 25:3671-3682. [PMID: 37964667 DOI: 10.1111/1462-2920.16534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023]
Abstract
Highly simplified microbial communities colonise rocks and soils of continental Antarctica ice-free deserts. These two habitats impose different selection pressures on organisms, yet the possible filtering effects on the diversity and composition of microbial communities have not hitherto been fully characterised. We hence compared fungal communities in rocks and soils in three localities of inner Victoria Land. We found low fungal diversity in both substrates, with a mean species richness of 28 across all samples, and significantly lower diversity in rocks than in soils. Rock and soil communities were strongly differentiated, with a multinomial species classification method identifying just three out of 328 taxa as generalists with no affinity for either substrate. Rocks were characterised by a higher abundance of lichen-forming fungi (typically Buellia, Carbonea, Pleopsidium, Lecanora, and Lecidea), possibly owing to the more protected environment and the porosity of rocks permitting photosynthetic activity. In contrast, soils were dominated by obligate yeasts (typically Naganishia and Meyerozyma), the abundances of which were correlated with edaphic factors, and the black yeast Cryomyces. Our study suggests that strong differences in selection pressures may account for the wide divergences of fungal communities in rocks and soils of inner Victoria Land.
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Affiliation(s)
- Fabiana Canini
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Luigimaria Borruso
- Faculty of Agricultural, Environmental and Food Sciences, Free University of Bozen, Bozen-Bolzano, Italy
| | - Kevin K Newsham
- British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Cambridge, UK
| | - Federica D'Alò
- Terrestrial Ecosystems Research Institute (IRET), National Research Council (CNR), Porano (TR), Italy
| | - Luigi P D'Acqui
- Institute of Polar Sciences (ISP), National Research Council (CNR), Messina, Italy
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
- Terrestrial Ecosystems Research Institute (IRET), National Research Council (CNR), Sesto Fiorentino (FI), Italy
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2
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Wu MH, Li T, Zhang GS, Wu FS, Chen T, Zhang BL, Wu XK, Liu GX, Zhang KC, Zhang W. Seasonal Variation of Hypolithic Microbiomes in the Gobi Desert : Seasonal Variation of Hypolithic Microbiomes in the Gobi Desert. MICROBIAL ECOLOGY 2023; 85:1382-1395. [PMID: 35583685 DOI: 10.1007/s00248-022-02043-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 05/12/2022] [Indexed: 05/10/2023]
Abstract
Understanding how microbial communities adapt to environmental stresses is critical for interpreting ecological patterns and microbial diversity. In the case of the Gobi Desert, little is known on the environmental factors that explain hypolithic colonization under quartz stones. By analyzing nine hypolithic communities across an arid gradient and the effects of the season of the year in the Hexi Corridor of this desert, we found a significant decrease in hypolithic colonization rates (from 47.24 to 15.73%) with the increasing drought gradient and found two distinct communities in Hot and Cold samples, which survived or proliferated after a hot or a cold period. While Cold communities showed a greater species diversity and a predominance of Cyanobacteria, Hot communities showed a predominance of members of the Proteobacteria and the Firmicutes. In comparison, Cold communities also possessed stronger functions in the photosynthesis and carbon metabolism. Based on the findings of this study, we proposed that the hypolithic communities of the Hexi Corridor of the Gobi Desert might follow a seasonal developmental cycle in which temperature play an important role. Thus after a critical thermal threshold is crossed, heterotrophic microorganisms predominate in the hot period, while Cyanobacteria predominate in the cold period.
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Affiliation(s)
- Ming-Hui Wu
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ting Li
- School of Ecology and Environmental Science, Yunnan University, Kunming, 650091, Yunnan, China
| | - Gao-Sen Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
| | - Fa-Si Wu
- National Research Center for Conservation of Ancient Wall Paintings and Earthen Sites, Department of Conservation Research, Dunhuang Academy, Dunhuang, Gansu, 736200, China
| | - Tuo Chen
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
| | - Bing-Lin Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
| | - Xiu-Kun Wu
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
| | - Guang-Xiu Liu
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China
| | - Ke-Cun Zhang
- Research Station of Gobi Desert Ecology and Environment in Dunhuang of Gansu Province, Dunhuang, Gansu, 736200, China
| | - Wei Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu, China.
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3
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Adaptation to Environmental Extremes Structures Functional Traits in Biological Soil Crust and Hypolithic Microbial Communities. mSystems 2022; 7:e0141921. [PMID: 35852333 PMCID: PMC9426607 DOI: 10.1128/msystems.01419-21] [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] [Indexed: 12/24/2022] Open
Abstract
Biological soil crusts (biocrusts) are widespread in drylands and deserts. At the microhabitat scale, they also host hypolithic communities that live under semitranslucent stones. Both environmental niches experience exposure to extreme conditions such as high UV radiation, desiccation, temperature fluctuations, and resource limitation. However, hypolithic communities are somewhat protected from extremes relative to biocrust communities. Conditions are otherwise similar, so comparing them can answer outstanding questions regarding adaptations to environmental extremes. Using metagenomic sequencing, we assessed the functional potential of dryland soil communities and identified the functional underpinnings of ecological niche differentiation in biocrusts versus hypoliths. We also determined the effect of the anchoring photoautotroph (moss or cyanobacteria). Genes and pathways differing in abundance between biocrusts and hypoliths indicate that biocrust communities adapt to the higher levels of UV radiation, desiccation, and temperature extremes through an increased ability to repair damaged DNA, sense and respond to environmental stimuli, and interact with other community members and the environment. Intracellular competition appears to be crucial to both communities, with biocrust communities using the Type VI Secretion System (T6SS) and hypoliths favoring a diversity of antibiotics. The dominant primary producer had a reduced effect on community functional potential compared with niche, but an abundance of genes related to monosaccharide, amino acid, and osmoprotectant uptake in moss-dominated communities indicates reliance on resources provided to heterotrophs by mosses. Our findings indicate that functional traits in dryland communities are driven by adaptations to extremes and we identify strategies that likely enable survival in dryland ecosystems. IMPORTANCE Biocrusts serve as a keystone element of desert and dryland ecosystems, stabilizing soils, retaining moisture, and serving as a carbon and nitrogen source in oligotrophic environments. Biocrusts cover approximately 12% of the Earth's terrestrial surface but are threatened by climate change and anthropogenic disturbance. Given their keystone role in ecosystem functioning, loss will have wide-spread consequences. Biocrust microbial constituents must withstand polyextreme environmental conditions including high UV exposure, desiccation, oligotrophic conditions, and temperature fluctuations over short time scales. By comparing biocrust communities with co-occurring hypolithic communities (which inhabit the ventral sides of semitranslucent stones and are buffered from environmental extremes), we identified traits that are likely key adaptations to extreme conditions. These include DNA damage repair, environmental sensing and response, and intracellular competition. Comparison of the two niches, which differ primarily in exposure levels to extreme conditions, makes this system ideal for understanding how functional traits are structured by the environment.
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4
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Weber B, Belnap J, Büdel B, Antoninka AJ, Barger NN, Chaudhary VB, Darrouzet-Nardi A, Eldridge DJ, Faist AM, Ferrenberg S, Havrilla CA, Huber-Sannwald E, Malam Issa O, Maestre FT, Reed SC, Rodriguez-Caballero E, Tucker C, Young KE, Zhang Y, Zhao Y, Zhou X, Bowker MA. What is a biocrust? A refined, contemporary definition for a broadening research community. Biol Rev Camb Philos Soc 2022; 97:1768-1785. [PMID: 35584903 PMCID: PMC9545944 DOI: 10.1111/brv.12862] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/10/2022] [Accepted: 04/12/2022] [Indexed: 12/22/2022]
Abstract
Studies of biological soil crusts (biocrusts) have proliferated over the last few decades. The biocrust literature has broadened, with more studies assessing and describing the function of a variety of biocrust communities in a broad range of biomes and habitats and across a large spectrum of disciplines, and also by the incorporation of biocrusts into global perspectives and biogeochemical models. As the number of biocrust researchers increases, along with the scope of soil communities defined as ‘biocrust’, it is worth asking whether we all share a clear, universal, and fully articulated definition of what constitutes a biocrust. In this review, we synthesize the literature with the views of new and experienced biocrust researchers, to provide a refined and fully elaborated definition of biocrusts. In doing so, we illustrate the ecological relevance and ecosystem services provided by them. We demonstrate that biocrusts are defined by four distinct elements: physical structure, functional characteristics, habitat, and taxonomic composition. We describe outgroups, which have some, but not all, of the characteristics necessary to be fully consistent with our definition and thus would not be considered biocrusts. We also summarize the wide variety of different types of communities that fall under our definition of biocrusts, in the process of highlighting their global distribution. Finally, we suggest the universal use of the Belnap, Büdel & Lange definition, with minor modifications: Biological soil crusts (biocrusts) result from an intimate association between soil particles and differing proportions of photoautotrophic (e.g. cyanobacteria, algae, lichens, bryophytes) and heterotrophic (e.g. bacteria, fungi, archaea) organisms, which live within, or immediately on top of, the uppermost millimetres of soil. Soil particles are aggregated through the presence and activity of these often extremotolerant biota that desiccate regularly, and the resultant living crust covers the surface of the ground as a coherent layer. With this detailed definition of biocrusts, illustrating their ecological functions and widespread distribution, we hope to stimulate interest in biocrust research and inform various stakeholders (e.g. land managers, land users) on their overall importance to ecosystem and Earth system functioning.
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Affiliation(s)
- Bettina Weber
- Division of Plant Sciences, Institute for Biology, University of Graz, Holteigasse 6, 8010, Graz, Austria.,Multiphase Chemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128, Mainz, Germany
| | - Jayne Belnap
- Southwest Biological Science Center, U.S. Geological Survey, 2290 S. Resource Blvd, Moab, UT, 84532, USA
| | - Burkhard Büdel
- Biology Institute, University of Kaiserslautern, PO Box 3049, 67653, Kaiserslautern, Germany
| | - Anita J Antoninka
- School of Forestry, Northern Arizona University, 200 E. Pine Knoll Drive, Box 15018, Flagstaff, AZ, 86011, USA
| | - Nichole N Barger
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Campus Box 334, Boulder, CO, 80309, USA
| | - V Bala Chaudhary
- Department of Environmental Studies, Dartmouth College, 6182 Steele Hall, 39 College Street, Hanover, NH, 03755, USA
| | - Anthony Darrouzet-Nardi
- Department of Biological Sciences, University of Texas at El Paso, 500 W. University Ave, El Paso, TX, 79968, USA
| | - David J Eldridge
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Akasha M Faist
- Department of Animal and Range Sciences, New Mexico State University, PO Box 30003, MSC 3-I, Las Cruces, NM, 88003, USA
| | - Scott Ferrenberg
- Department of Biology, New Mexico State University, PO Box 30001, MSC 3AF, Las Cruces, NM, 88003, USA
| | - Caroline A Havrilla
- Department of Forest and Rangeland Stewardship, Colorado State University, 1472 Campus Delivery, Colorado State University, Fort Collins, CO, 80521, USA
| | - Elisabeth Huber-Sannwald
- Division of Environmental Sciences, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Col. 4ta Sección, CP 78216, San Luis Potosi, SLP, Mexico
| | - Oumarou Malam Issa
- Institute of Ecology and Environmental Sciences of Paris (IEES-Paris), SU/IRD/CNRS/INRAE/UPEC, 32, Avenue Henry Varagnat, F-93143, Bondy Cedex, France
| | - Fernando T Maestre
- Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef", Universidad de Alicante, Carretera de San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Spain.,Departamento de Ecología, Universidad de Alicante, Carretera de San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Spain
| | - Sasha C Reed
- Southwest Biological Science Center, U.S. Geological Survey, 2290 S. Resource Blvd, Moab, UT, 84532, USA
| | - Emilio Rodriguez-Caballero
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128, Mainz, Germany.,Department of Agronomy and Centro de Investigación de Colecciones Científicas (CECOUAL), Universidad de Almería, carretera Sacramento s/n, 04120, La cañada de San Urbano, Almeria, Spain
| | - Colin Tucker
- USDA Forest Service, Northern Research Station, 410 MacInnes Drive, Houghton, MI, 49931-1134, USA
| | - Kristina E Young
- Extension Agriculture and Natural Resources, Utah State University, 1850 S. Aggie Blvd, Moab, UT, 84532, USA
| | - Yuanming Zhang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 818 South Bejing Road, Urumqi City, 830011, Xinjiang, China
| | - Yunge Zhao
- Institute of Soil and Water Conservation, Northwest A & F University, 26 Xinong Road, Yangling, Shaanxi, 712100, China
| | - Xiaobing Zhou
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 818 South Bejing Road, Urumqi City, 830011, Xinjiang, China
| | - Matthew A Bowker
- School of Forestry, Northern Arizona University, 200 E. Pine Knoll Drive, Box 15018, Flagstaff, AZ, 86011, USA
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5
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Abstract
Arid ecosystems cover ∼40% of the Earth's terrestrial surface and store a high proportion of the global nitrogen (N) pool. They are low-productivity, low-biomass, and polyextreme ecosystems, i.e., with (hyper)arid and (hyper)oligotrophic conditions and high surface UV irradiation and evapotranspiration. These polyextreme conditions severely limit the presence of macrofauna and -flora and, particularly, the growth and productivity of plant species. Therefore, it is generally recognized that much of the primary production (including N-input processes) and nutrient biogeochemical cycling (particularly N cycling) in these ecosystems are microbially mediated. Consequently, we present a comprehensive survey of the current state of knowledge of biotic and abiotic N-cycling processes of edaphic (i.e., open soil, biological soil crust, or plant-associated rhizosphere and rhizosheath) and hypo/endolithic refuge niches from drylands in general, including hot, cold, and polar desert ecosystems. We particularly focused on the microbially mediated biological nitrogen fixation, N mineralization, assimilatory and dissimilatory nitrate reduction, and nitrification N-input processes and the denitrification and anaerobic ammonium oxidation (anammox) N-loss processes. We note that the application of modern meta-omics and related methods has generated comprehensive data sets on the abundance, diversity, and ecology of the different N-cycling microbial guilds. However, it is worth mentioning that microbial N-cycling data from important deserts (e.g., Sahara) and quantitative rate data on N transformation processes from various desert niches are lacking or sparse. Filling this knowledge gap is particularly important, as climate change models often lack data on microbial activity and environmental microbial N-cycling communities can be key actors of climate change by producing or consuming nitrous oxide (N2O), a potent greenhouse gas.
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6
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Mehda S, Muñoz-Martín MÁ, Oustani M, Hamdi-Aïssa B, Perona E, Mateo P. Lithic cyanobacterial communities in the polyextreme Sahara Desert: implications for the search for the limits of life. Environ Microbiol 2021; 24:451-474. [PMID: 34837297 DOI: 10.1111/1462-2920.15850] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/25/2021] [Accepted: 11/12/2021] [Indexed: 11/29/2022]
Abstract
The hyperarid Sahara Desert presents extreme and persistent dry conditions with a limited number of hours during which the moisture availability, temperature and light allow phototrophic growth. Some cyanobacteria can live in these hostile conditions by seeking refuge under (hypolithic) or inside (endolithic) rocks, by colonizing porous spaces (cryptoendoliths) or fissures in stones (chasmoendoliths). Chroococcidiopsis spp. have been reported as the dominant or even the only phototrophs in these hot desert lithic communities. However, the results of this study reveal the high diversity of and variability in cyanobacteria among the sampled habitats in the Sahara Desert. The chasmoendolithic samples presented high coccoid cyanobacteria abundances, although the dominant cyanobacteria were distinct among different locations. A high predominance of a newly described cyanobacterium, Pseudoacaryochloris sahariense, was found in hard, compact, and more opaque stones with cryptoendolithic colonization. On the other hand, the hypolithic samples were dominated by filamentous, non-heterocystous cyanobacteria. Thermophysiological bioassays confirmed desiccation and extreme temperature tolerance as drivers in the cyanobacterial community composition of these lithic niches. The results of the present study provide key factors for understanding life strategies under polyextreme environmental conditions. The isolated strains, especially the newly described cyanobacterium P. sahariense, might represent suitable microorganisms in astrobiology studies aimed at investigating the limits of life.
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Affiliation(s)
- Smail Mehda
- Departamento de Biología. Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, 28049, Spain.,Laboratory of Biogeochemistry of Desert Areas, University of Ouargla, Ouargla, 30000, Algeria.,Faculty of Life and Natural Sciences, Department of Agronomy, University of El Oued, El Oued, 39000, Algeria
| | - M Ángeles Muñoz-Martín
- Departamento de Biología. Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Mabrouka Oustani
- Laboratory of Saharan Bio-Resources: Preservation and Development, University of Ouargla, Ouargla, 30000, Algeria
| | - Baelhadj Hamdi-Aïssa
- Laboratory of Biogeochemistry of Desert Areas, University of Ouargla, Ouargla, 30000, Algeria
| | - Elvira Perona
- Departamento de Biología. Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Pilar Mateo
- Departamento de Biología. Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, 28049, Spain
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7
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Lebre PH, Bottos E, Makhalanyane TP, Hogg I, Cowan DA. Islands in the sand: are all hypolithic microbial communities the same? FEMS Microbiol Ecol 2021; 97:5928546. [PMID: 33068395 DOI: 10.1093/femsec/fiaa216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/16/2020] [Indexed: 01/04/2023] Open
Abstract
Hypolithic microbial communities (hypolithons) are complex assemblages of phototrophic and heterotrophic organisms associated with the ventral surfaces of translucent minerals embedded in soil surfaces. Past studies on the assembly, structure and function of hypolithic communities have tended to use composite samples (i.e. bulked hypolithic biomass) with the underlying assumption that samples collected from within a 'homogeneous' locality are phylogenetically homogeneous. In this study, we question this assumption by analysing the prokaryote phylogenetic diversity of multiple individual hypolithons: i.e. asking the seemingly simple question of 'Are all hypolithons the same'? Using 16S rRNA gene-based phylogenetic analysis of hypolithons recovered for a localized moraine region in the Taylor Valley, McMurdo Dry Valleys, Antarctica, we demonstrate that these communities are heterogeneous at very small spatial scales (<5 m). Using null models of phylogenetic turnover, we showed that this heterogeneity between hypolithons is probably due to stochastic effects such as dispersal limitations, which is entirely consistent with the physically isolated nature of the hypolithic communities ('islands in the sand') and the almost complete absence of a liquid continuum as a mode of microbial transport between communities.
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Affiliation(s)
- Pedro H Lebre
- Centre for Microbial Ecology and Genomic, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Lynwood Road, Hatfield, Pretoria, 0028, South Africa
| | - Eric Bottos
- Department of Biological Sciences, Thompson Rivers University, 805 TRU Way, Kamloops, British Colombia, BC V2C 0C8, Canada
| | - Thulani P Makhalanyane
- Centre for Microbial Ecology and Genomic, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Lynwood Road, Hatfield, Pretoria, 0028, South Africa
| | - Ian Hogg
- Canadian High Arctic Research Station, rue Uvajuq place, Cambridge Bay, Nunavut, CP 2150, Canada
| | - Don A Cowan
- Centre for Microbial Ecology and Genomic, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Lynwood Road, Hatfield, Pretoria, 0028, South Africa
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8
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Gwizdala M, Lebre PH, Maggs-Kölling G, Marais E, Cowan DA, Krüger TPJ. Sub-lithic photosynthesis in hot desert habitats. Environ Microbiol 2021; 23:3867-3880. [PMID: 33817951 DOI: 10.1111/1462-2920.15505] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/03/2021] [Indexed: 11/26/2022]
Abstract
In hyper-arid soil environments, photosynthetic microorganisms are largely restricted to hypolithic (sub-lithic) habitats: i.e., on the ventral surfaces of translucent pebbles in desert pavements. Here, we combined fluorometric, spectroscopic, biochemical and metagenomic approaches to investigate in situ the light transmission properties of quartz stones in the Namib Desert, and assess the photosynthetic activity of the underlying hypolithic cyanobacterial biofilms. Quartz pebbles greatly reduced the total photon flux to the ventral surface biofilms and filtered out primarily the short wavelength portion of the solar spectrum. Chlorophylls d and f were not detected in biofilm pigment extracts; however, hypolithic cyanobacterial communities showed some evidence of adaptation to sub-lithic conditions, including the prevalence of genes encoding Helical Carotenoid Proteins, which are associated with desiccation stress. Under water-saturated conditions, hypolithic communities showed no evidence of light stress, even when the quartz stones were exposed to full midday sunlight. This initial study creates a foundation for future in-situ and laboratory exploration of various adaptation mechanisms employed by photosynthetic organisms forming hypolithic microbial communities.
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Affiliation(s)
- Michal Gwizdala
- Department of Physics, University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa.,Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa
| | - Pedro H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa
| | | | - Eugene Marais
- Gobabeb-Namib Research Institute, Walvis Bay, Namibia
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa
| | - Tjaart P J Krüger
- Department of Physics, University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa.,Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa
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9
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Choe YH, Kim M, Lee YK. Distinct Microbial Communities in Adjacent Rock and Soil Substrates on a High Arctic Polar Desert. Front Microbiol 2021; 11:607396. [PMID: 33488547 PMCID: PMC7819959 DOI: 10.3389/fmicb.2020.607396] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/08/2020] [Indexed: 01/04/2023] Open
Abstract
Understanding microbial niche variability in polar regions can provide insights into the adaptive diversification of microbial lineages in extreme environments. Compositions of microbial communities in Arctic soils are well documented but a comprehensive multidomain diversity assessment of rocks remains insufficiently studied. In this study, we obtained two types of rocks (sandstone and limestone) and soils around the rocks in a high Arctic polar desert (Svalbard), and examined the compositions of archaeal, bacterial, fungal, and protistan communities in the rocks and soils. The microbial community structure differed significantly between rocks and soils across all microbial groups at higher taxonomic levels, indicating that Acidobacteria, Gemmatimonadetes, Latescibacteria, Rokubacteria, Leotiomycetes, Pezizomycetes, Mortierellomycetes, Sarcomonadea, and Spirotrichea were more abundant in soils, whereas Cyanobacteria, Deinococcus-Thermus, FBP, Lecanoromycetes, Eurotiomycetes, Trebouxiophyceae, and Ulvophyceae were more abundant in rocks. Interestingly, fungal communities differed markedly between two different rock types, which is likely to be ascribed to the predominance of distinct lichen-forming fungal taxa (Verrucariales in limestone, and Lecanorales in sandstone). This suggests that the physical or chemical properties of rocks could be a major determinant in the successful establishment of lichens in lithic environments. Furthermore, the biotic interactions among microorganisms based on co-occurrence network analysis revealed that Polyblastia and Verrucaria in limestone, and Atla, Porpidia, and Candelariella in sandstone play an important role as keystone taxa in the lithic communities. Our study shows that even in niches with the same climate regime and proximity to each other, heterogeneity of edaphic and lithic niches can affect microbial community assembly, which could be helpful in comprehensively understanding the effects of niche on microbial assembly in Arctic terrestrial ecosystems.
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Affiliation(s)
- Yong-Hoe Choe
- Korea Polar Research Institute, Incheon, South Korea
| | - Mincheol Kim
- Korea Polar Research Institute, Incheon, South Korea
| | - Yoo Kyung Lee
- Korea Polar Research Institute, Incheon, South Korea
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10
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Mergelov N, Dolgikh A, Shorkunov I, Zazovskaya E, Soina V, Yakushev A, Fedorov-Davydov D, Pryakhin S, Dobryansky A. Hypolithic communities shape soils and organic matter reservoirs in the ice-free landscapes of East Antarctica. Sci Rep 2020; 10:10277. [PMID: 32581283 PMCID: PMC7314805 DOI: 10.1038/s41598-020-67248-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/04/2020] [Indexed: 12/29/2022] Open
Abstract
The soils of East Antarctica have no rhizosphere with the bulk of organo-mineral interactions confined to the thin microbial and cryptogamic crusts that occur in open or cryptic niches and are collectively known as biological soil crust (BSC). Here we demonstrate that cryptic hypolithic varieties of BSC in the Larsemann Hills of East Antarctica contribute to the buildup of soil organic matter and produce several types of continuous organogenous horizons within the topsoil with documented clusters of at least 100 m2. Such hypolithic horizons accumulate 0.06-4.69% of organic carbon (TOC) with isotopic signatures (δ13Corg) within the range of -30.2 - -24.0‰, and contain from 0 to 0.38% total nitrogen (TN). The properties of hypolithic organic matter alternate between cyanobacteria- and moss-dominated horizons, which are linked to the meso- and microtopography patterns and moisture gradients. The major part of TOC that is stored in hypolithic horizons has modern or centenary 14C age, while the minor part is stabilized on a millennial timescale through shallow burial and association with minerals. Our findings suggest that hypolithic communities create a "gateway" for organic carbon to enter depauperate soils of the Larsemann Hills and contribute to the carbon reservoir of the topsoil at a landscape level.
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Affiliation(s)
- Nikita Mergelov
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia.
| | - Andrey Dolgikh
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia
| | - Ilya Shorkunov
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia
| | - Elya Zazovskaya
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia
| | - Vera Soina
- Faculty of Soil Science, Moscow State University, 119991, Moscow, Russia
| | - Andrey Yakushev
- Faculty of Soil Science, Moscow State University, 119991, Moscow, Russia
| | - Dmitry Fedorov-Davydov
- Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, 142290, Pushchino, Russia
| | - Sergey Pryakhin
- Arctic and Antarctic Research Institute, 199397, Saint Petersburg, Russia
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Fisher K, Jefferson JS, Vaishampayan P. Bacterial Communities of Mojave Desert Biological Soil Crusts Are Shaped by Dominant Photoautotrophs and the Presence of Hypolithic Niches. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2019.00518] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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12
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Cao W, Xiong Y, Zhao D, Tan H, Qu J. Bryophytes and the symbiotic microorganisms, the pioneers of vegetation restoration in karst rocky desertification areas in southwestern China. Appl Microbiol Biotechnol 2020; 104:873-891. [PMID: 31822979 PMCID: PMC6943408 DOI: 10.1007/s00253-019-10235-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/22/2019] [Accepted: 10/31/2019] [Indexed: 01/03/2023]
Abstract
In karst rocky desertification areas, bryophytes coexist with algae, bacteria, and fungi on exposed calcareous rocks to form a bryophyte crust, which plays an irreplaceable role in the restoration of karst degraded ecosystems. We investigated the biodiversity of crust bryophytes in karst rocky desertification areas from Guizhou Province, China. A total of 145 species in 22 families and 56 genera were identified. According to frequency and coverage, seven candidate dominant mosses were screened out, and five drought-resistant indexes of them were measured. Hypnum leptothallum, Racopilum cuspidigerum, and Hyophila involuta have high drought adaptability. We explored the interactions between two dominant mosses (H. leptothallum, H. involuta) and the structure of microbial communities in three karst rocky desertification types. Microbial diversity and function analysis showed that both moss species and karst rocky desertification types affect microbial communities. Moss species much more strongly affected the diversity and changed the community composition of these microbial groups. Bacteria were more sensitive in the microbiome as their communities changed strongly between mosses and drought resistance factors. Moreover, several species of fungi and bacteria could be significantly associated with three drought-resistant indexes: Pro (free proline content), SOD (superoxide dismutase activity), and POD (peroxidase activity), which were closely related to the drought adaptability of mosses. Our results enforced the potential role of moss-associated microbes that are important components involved in the related biological processes when bryophytes adapted to arid habitats, or as one kind of promoters in the distribution pattern of early mosses succession in karst rocky desertification areas.
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Affiliation(s)
- Wei Cao
- College of Life Sciences, Guizhou University, Guiyang, 550025, China
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang, 550025, China
| | - Yuanxin Xiong
- College of Life Sciences, Guizhou University, Guiyang, 550025, China
| | - Degang Zhao
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang, 550025, China
| | - Hongying Tan
- Guiyang A'ha Lake National Wetland Park Management Division, Guiyang, 550002, China
| | - Jiaojiao Qu
- College of Tea Sciences, Guizhou University, Guiyang, 550025, China.
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13
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Namib Desert primary productivity is driven by cryptic microbial community N-fixation. Sci Rep 2018; 8:6921. [PMID: 29720684 PMCID: PMC5932006 DOI: 10.1038/s41598-018-25078-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/09/2018] [Indexed: 12/03/2022] Open
Abstract
Carbon exchange in drylands is typically low, but during significant rainfall events (wet anomalies) drylands act as a C sink. During these anomalies the limitation on C uptake switches from water to nitrogen. In the Namib Desert of southern Africa, the N inventory in soil organic matter available for mineralisation is insufficient to support the observed increase in primary productivity. The C4 grasses that flourish after rainfall events are not capable of N fixation, and so there is no clear mechanism for adequate N fixation in dryland ecosystems to support rapid C uptake. Here we demonstrate that N fixation by photoautotrophic hypolithic communities forms the basis for the N budget for plant productivity events in the Namib Desert. Stable N isotope (δ15N) values of Namib Desert hypolithic biomass, and surface and subsurface soils were measured over 3 years across dune and gravel plain biotopes. Hypoliths showed significantly higher biomass and lower δ15N values than soil organic matter. The δ15N values of hypoliths approach the theoretical values for nitrogen fixation. Our results are strongly indicative that hypolithic communities are the foundation of productivity after rain events in the Namib Desert and are likely to play similar roles in other arid environments.
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14
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Hinchliffe G, Bollard-Breen B, Cowan DA, Doshi A, Gillman LN, Maggs-Kolling G, de Los Rios A, Pointing SB. Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert. Front Microbiol 2017; 8:2083. [PMID: 29312153 PMCID: PMC5663711 DOI: 10.3389/fmicb.2017.02083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/11/2017] [Indexed: 11/13/2022] Open
Abstract
The hyper-arid central region of the Namib Desert is characterized by quartz desert pavement terrain that is devoid of vascular plant covers. In this extreme habitat the only discernible surface covers are epilithic lichens that colonize exposed surfaces of quartz rocks. These lichens are highly susceptible to disturbance and so field surveys have been limited due to concerns about disturbing this unusual desert feature. Here we present findings that illustrate how non-destructive surveys based upon advanced photogrammetry techniques can yield meaningful and novel scientific data on these lichens. We combined 'structure from motion analysis,' computer vision and GIS to create 3-dimensional point clouds from two-dimensional imagery. The data were robust in its application to estimating absolute lichen cover. An orange Stellarangia spp. assemblage had coverage of 22.8% of available substrate, whilst for a black Xanthoparmelia spp. assemblage coverage was markedly lower at 0.6% of available substrate. Hyperspectral signatures for both lichens were distinct in the near-infra red range indicating that Xanthoparmelia spp. was likely under relatively more moisture stress than Stellarangia spp. at the time of sampling, and we postulate that albedo effects may have contributed to this in the black lichen. Further transformation of the data revealed a colonization preference for west-facing quartz surfaces and this coincides with prevailing winds for marine fog that is the major source of moisture in this system. Furthermore, a three-dimensional 'fly through' of the lichen habitat was created to illustrate how the application of computer vision in microbiology has further potential as a research and education tool. We discuss how advanced photogrammetry could be applied in astrobiology using autonomous rovers to add quantitative ecological data for visible surface colonization on the surface of Mars.
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Affiliation(s)
- Graham Hinchliffe
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
| | - Barbara Bollard-Breen
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
| | - Don A. Cowan
- The Genomics Research Institute, University of Pretoria, Pretoria, South Africa
| | - Ashray Doshi
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
| | - Len N. Gillman
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
| | | | - Asuncion de Los Rios
- Departamento de Biogeoquímica y Ecología Microbiana, Museo Nacional de Ciencias Naturales, Madrid, Spain
| | - Stephen B. Pointing
- Division of Science, Yale-NUS College, National University of Singapore, Singapore, Singapore
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Christian K, Kaestli M, Gibb K. Spatial patterns of hypolithic cyanobacterial diversity in Northern Australia. Ecol Evol 2017; 7:7023-7033. [PMID: 28904780 PMCID: PMC5587464 DOI: 10.1002/ece3.3248] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/13/2017] [Accepted: 06/25/2017] [Indexed: 02/01/2023] Open
Abstract
Photosynthetic microbial communities under translucent rocks (hypolithic) are found in many arid regions. At the global scale, there has been little intercontinental gene flow, and at a local scale, microbial composition is related to fine‐scale features of the rocks and their environment. Few studies have investigated patterns of hypolithic community composition at intermediate distances. We examined hypolithic cyanobacterial diversity in semi‐arid Australia along a 10‐km transect by sampling six rocks from four adjacent 1 m2 quadrats (“distance zero”) and from additional quadrats at 10, 100, 1,000, and 10,000 m to test the hypothesis that diversity would increase with the number of rocks sampled and distance. A total of 3,108 cyanobacterial operational taxonomic units (OTUs) were detected. Most were neither widespread nor abundant. The few that were widespread tended to be abundant. There was no difference in the community composition between the four sites at distance zero, but the samples 10 m away were significantly different, as were those at all other distances compared to distance zero. Many additional OTUs were recorded with increasing distance up to 100 m. These patterns of distribution are consistent with a colonization model involving dispersal from rock to rock. Our results indicate that distance was a significant factor that can be confounded by interrock differences. Most diversity was represented in the first 100 m of the transect, with an additional 1.5% of the total diversity added by the sample at 1 km, but only 0.2% added with the addition of the 10‐km site.
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Affiliation(s)
- Keith Christian
- Research Institute for the Environment and Livelihoods Charles Darwin University Darwin Northern Territory Australia
| | - Mirjam Kaestli
- Research Institute for the Environment and Livelihoods Charles Darwin University Darwin Northern Territory Australia
| | - Karen Gibb
- Research Institute for the Environment and Livelihoods Charles Darwin University Darwin Northern Territory Australia
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16
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Schmidt SK, Vimercati L, Darcy JL, Arán P, Gendron EM, Solon AJ, Porazinska D, Dorador C. A Naganishia in high places: functioning populations or dormant cells from the atmosphere? Mycology 2017; 8:153-163. [PMID: 30123637 PMCID: PMC6059072 DOI: 10.1080/21501203.2017.1344154] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 06/15/2017] [Indexed: 12/16/2022] Open
Abstract
Here, we review the current state of knowledge concerning high-elevation members of the extremophilic Cryptococcus albidus clade (now classified as the genus Naganishia). These fungi dominate eukaryotic microbial communities across the highest elevation, soil-like material (tephra) on volcanoes such as Llullaillaco, Socompa, and Saírecabur in the Atacama region of Chile, Argentina, and Bolivia. Recent studies indicate that Naganishia species are among the most resistant organisms to UV radiation, and a strain of N. friedmannii from Volcán Llullaillaco is the first organism that is known to grow during the extreme, diurnal freeze-thaw cycles that occur on a continuous basis at elevations above 6000 m.a.s.l. in the Atacama region. These and other extremophilic traits discussed in this review may serve a dual purpose of allowing Naganishia species to survive long-distance transport through the atmosphere and to survive the extreme conditions found at high elevations. Current evidence indicates that there are frequent dispersal events between high-elevation volcanoes of Atacama region and the Dry Valleys of Antarctica via "Rossby Wave" merging of the polar and sub-tropical jet streams. This dispersal hypothesis needs further verification, as does the hypothesis that Naganishia species are flexible "opportunitrophs" that can grow during rare periods of water (from melting snow) and nutrient availability (from Aeolian inputs) in one of the most extreme terrestrial habitats on Earth.
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Affiliation(s)
- Steven K Schmidt
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Lara Vimercati
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - John L Darcy
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Pablo Arán
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta & Centre for Biotechnology and Bioengineering (CeBiB), Universidad de Antofagasta, Antofagasta, Chile
- Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
| | - Eli M.S Gendron
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
- Molecular, Cellular, and Developmental Biology Department, University of Colorado, Boulder, CO, USA
| | - Adam J Solon
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Dorota Porazinska
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Cristina Dorador
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta & Centre for Biotechnology and Bioengineering (CeBiB), Universidad de Antofagasta, Antofagasta, Chile
- Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
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