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Männistö MK, Ahonen SHK, Ganzert L, Tiirola M, Stark S, Häggblom MM. Bacterial and fungal communities in sub-Arctic tundra heaths are shaped by contrasting snow accumulation and nutrient availability. FEMS Microbiol Ecol 2024; 100:fiae036. [PMID: 38549428 PMCID: PMC10996926 DOI: 10.1093/femsec/fiae036] [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: 10/12/2023] [Revised: 02/26/2024] [Accepted: 03/27/2024] [Indexed: 04/06/2024] Open
Abstract
Climate change is affecting winter snow conditions significantly in northern ecosystems but the effects of the changing conditions for soil microbial communities are not well-understood. We utilized naturally occurring differences in snow accumulation to understand how the wintertime subnivean conditions shape bacterial and fungal communities in dwarf shrub-dominated sub-Arctic Fennoscandian tundra sampled in mid-winter, early, and late growing season. Phospholipid fatty acid (PLFA) and quantitative PCR analyses indicated that fungal abundance was higher in windswept tundra heaths with low snow accumulation and lower nutrient availability. This was associated with clear differences in the microbial community structure throughout the season. Members of Clavaria spp. and Sebacinales were especially dominant in the windswept heaths. Bacterial biomass proxies were higher in the snow-accumulating tundra heaths in the late growing season but there were only minor differences in the biomass or community structure in winter. Bacterial communities were dominated by members of Alphaproteobacteria, Actinomycetota, and Acidobacteriota and were less affected by the snow conditions than the fungal communities. The results suggest that small-scale spatial patterns in snow accumulation leading to a mosaic of differing tundra heath vegetation shapes bacterial and fungal communities as well as soil carbon and nutrient availability.
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Affiliation(s)
- Minna K Männistö
- Natural Resources Institute Finland, Ounasjoentie 6, FI-96200 Rovaniemi, Finland
| | - Saija H K Ahonen
- Ecology and Genetics Research Unit, University of Oulu, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland
| | - Lars Ganzert
- Natural Resources Institute Finland, Ounasjoentie 6, FI-96200 Rovaniemi, Finland
- Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Zur alten Fischerhütte 2, 16775 Stechlin, Germany
| | - Marja Tiirola
- Department of Biological and Environmental Science, University of Jyväskylä, Survontie 9, FI-40014 Jyväskylä, Finland
| | - Sari Stark
- Arctic Centre, University of Lapland, Pohjoisranta 4, Fl-96101 Rovaniemi, Finland
| | - Max M Häggblom
- Natural Resources Institute Finland, Ounasjoentie 6, FI-96200 Rovaniemi, Finland
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, United States
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Brock MT, Morrison HG, Maignien L, Weinig C. Impacts of sample handling and storage conditions on archiving physiologically active soil microbial communities. FEMS Microbiol Lett 2024; 371:fnae044. [PMID: 38866716 DOI: 10.1093/femsle/fnae044] [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: 02/07/2023] [Revised: 03/30/2024] [Accepted: 06/11/2024] [Indexed: 06/14/2024] Open
Abstract
Soil microbial communities are fundamental to ecosystem processes and plant growth, yet community composition is seasonally and successionally dynamic, which interferes with long-term iterative experimentation of plant-microbe interactions. We explore how soil sample handling (e.g. filtering) and sample storage conditions impact the ability to revive the original, physiologically active, soil microbial community. We obtained soil from agricultural fields in Montana and Oklahoma, USA and samples were sieved to 2 mm or filtered to 45 µm. Sieved and filtered soil samples were archived at -20°C or -80°C for 50 days and revived for 2 or 7 days. We extracted DNA and the more transient RNA pools from control and treatment samples and characterized microbial communities using 16S amplicon sequencing. Filtration and storage treatments significantly altered soil microbial communities, impacting both species richness and community composition. Storing sieved soil at -20°C did not alter species richness and resulted in the least disruption to the microbial community composition in comparison to nonarchived controls as characterized by RNA pools from soils of both sites. Filtration significantly altered composition but not species richness. Archiving sieved soil at -20°C could allow for long-term and repeated experimentation on preserved physiologically active microbial communities.
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Affiliation(s)
- Marcus T Brock
- Department of Botany, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, United States
| | - Hilary G Morrison
- Marine Biological Laboratory, Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, 7 MBL Street, Woods Hole, MA 02543, United States
| | - Loïs Maignien
- Marine Biological Laboratory, Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, 7 MBL Street, Woods Hole, MA 02543, United States
- Laboratory of Microbiology of Extreme Environments, UMR 6197 - CNRS-Ifremer-UBO, Institut Universitaire Européen de la Mer (IUEM), Université de Bretagne Occidentale (UBO), Technopole Brest-Iroise, 4 rue Dumont d'Urville, 29280 Plouzané, France
| | - Cynthia Weinig
- Department of Botany, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, United States
- Program in Ecology, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, United States
- Department of Molecular Biology, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, United States
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3
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Doherty SJ, Busby RR, Baker CCM, Barbato RA. Rhizosphere microbial community structure differs between constant subzero and freeze-thaw temperature regimes in a subarctic soil. FEMS Microbiol Ecol 2023; 99:fiad147. [PMID: 37962959 DOI: 10.1093/femsec/fiad147] [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: 07/18/2023] [Accepted: 11/13/2023] [Indexed: 11/16/2023] Open
Abstract
In the Arctic and subarctic, climate change is causing reduced snowpack extent and earlier snowmelt. Shallower snowpack decreases the thermal insulation of underlying soil and results in more freeze-thaw conditions reflective of dynamic air temperatures. The aim of this study was to determine the effect of alternative temperature regimes on overall microbial community structure and rhizosphere recruitment across representatives of three subarctic plant functional groups. We hypothesized that temperature regime would influence rhizosphere community structure more than plant type. Planted microcosms were established using a tree, forb, grass, or no plant control and subjected to either freeze-thaw cycling or static subzero temperatures. Our results showed rhizosphere communities exhibited reduced diversity compared to bulk soils, and were influenced by temperature conditions and to a lesser extent plant type. We found that plants have a core microbiome that is persistent under different winter temperature scenarios but also have temperature regime-specific rhizosphere microbes. Freeze-thaw cycling resulted in greater community shifts from the pre-incubation soils when compared to constant subzero temperature. This finding suggests that wintertime snowpack conditions may be a significant factor for plant-microbe interactions upon spring thaw.
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Affiliation(s)
- Stacey J Doherty
- United States Army, Engineer Research Development Center, Cold Regions Research and Engineering Laboratory, Hanover, NH 03755, United States
| | - Ryan R Busby
- United States Army, Engineer Research Development Center, Construction Engineering Research Laboratory, Champaign, IL 61826, United States
| | - Christopher C M Baker
- United States Army, Engineer Research Development Center, Cold Regions Research and Engineering Laboratory, Hanover, NH 03755, United States
| | - Robyn A Barbato
- United States Army, Engineer Research Development Center, Cold Regions Research and Engineering Laboratory, Hanover, NH 03755, United States
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4
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Cui Y, Peng S, Delgado-Baquerizo M, Rillig MC, Terrer C, Zhu B, Jing X, Chen J, Li J, Feng J, He Y, Fang L, Moorhead DL, Sinsabaugh RL, Peñuelas J. Microbial communities in terrestrial surface soils are not widely limited by carbon. GLOBAL CHANGE BIOLOGY 2023; 29:4412-4429. [PMID: 37277945 DOI: 10.1111/gcb.16765] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 06/07/2023]
Abstract
Microbial communities in soils are generally considered to be limited by carbon (C), which could be a crucial control for basic soil functions and responses of microbial heterotrophic metabolism to climate change. However, global soil microbial C limitation (MCL) has rarely been estimated and is poorly understood. Here, we predicted MCL, defined as limited availability of substrate C relative to nitrogen and/or phosphorus to meet microbial metabolic requirements, based on the thresholds of extracellular enzyme activity across 847 sites (2476 observations) representing global natural ecosystems. Results showed that only about 22% of global sites in terrestrial surface soils show relative C limitation in microbial community. This finding challenges the conventional hypothesis of ubiquitous C limitation for soil microbial metabolism. The limited geographic extent of C limitation in our study was mainly attributed to plant litter, rather than soil organic matter that has been processed by microbes, serving as the dominant C source for microbial acquisition. We also identified a significant latitudinal pattern of predicted MCL with larger C limitation at mid- to high latitudes, whereas this limitation was generally absent in the tropics. Moreover, MCL significantly constrained the rates of soil heterotrophic respiration, suggesting a potentially larger relative increase in respiration at mid- to high latitudes than low latitudes, if climate change increases primary productivity that alleviates MCL at higher latitudes. Our study provides the first global estimates of MCL, advancing our understanding of terrestrial C cycling and microbial metabolic feedback under global climate change.
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Affiliation(s)
- Yongxing Cui
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Shushi Peng
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Manuel Delgado-Baquerizo
- Laboratorio de Biodiversidad y Funcionamiento Ecosistémico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Sevilla, Spain
- Unidad Asociada CSIC-UPO (BioFun). Universidad Pablo de Olavide, Sevilla, Spain
| | | | - César Terrer
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Boston, Massachusetts, USA
| | - Biao Zhu
- Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Xin Jing
- State Key Laboratory of Grassland Agro-Ecosystems, and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Ji Chen
- Department of Agroecology, Aarhus University, Tjele, Denmark
| | - Jinquan Li
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China
| | - Jiao Feng
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Yue He
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Linchuan Fang
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, China
| | - Daryl L Moorhead
- Department of Environmental Sciences, University of Toledo, Toledo, Ohio, USA
| | - Robert L Sinsabaugh
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, Catalonia, Spain
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Sannino C, Qi W, Rüthi J, Stierli B, Frey B. Distinct taxonomic and functional profiles of high Arctic and alpine permafrost-affected soil microbiomes. ENVIRONMENTAL MICROBIOME 2023; 18:54. [PMID: 37328770 DOI: 10.1186/s40793-023-00509-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/02/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Global warming is affecting all cold environments, including the European Alps and Arctic regions. Here, permafrost may be considered a unique ecosystem harboring a distinct microbiome. The frequent freeze-thaw cycles occurring in permafrost-affected soils, and mainly in the seasonally active top layers, modify microbial communities and consequently ecosystem processes. Although taxonomic responses of the microbiomes in permafrost-affected soils have been widely documented, studies about how the microbial genetic potential, especially pathways involved in C and N cycling, changes between active-layer soils and permafrost soils are rare. Here, we used shotgun metagenomics to analyze the microbial and functional diversity and the metabolic potential of permafrost-affected soil collected from an alpine site (Val Lavirun, Engadin area, Switzerland) and a High Arctic site (Station Nord, Villum Research Station, Greenland). The main goal was to discover the key genes abundant in the active-layer and permafrost soils, with the purpose to highlight the potential role of the functional genes found. RESULTS We observed differences between the alpine and High Arctic sites in alpha- and beta-diversity, and in EggNOG, CAZy, and NCyc datasets. In the High Arctic site, the metagenome in permafrost soil had an overrepresentation (relative to that in active-layer soil) of genes involved in lipid transport by fatty acid desaturate and ABC transporters, i.e. genes that are useful in preventing microorganisms from freezing by increasing membrane fluidity, and genes involved in cell defense mechanisms. The majority of CAZy and NCyc genes were overrepresented in permafrost soils relative to active-layer soils in both localities, with genes involved in the degradation of carbon substrates and in the degradation of N compounds indicating high microbial activity in permafrost in response to climate warming. CONCLUSIONS Our study on the functional characteristics of permafrost microbiomes underlines the remarkably high functional gene diversity of the High Arctic and temperate mountain permafrost, including a broad range of C- and N-cycling genes, and multiple survival and energetic metabolisms. Their metabolic versatility in using organic materials from ancient soils undergoing microbial degradation determine organic matter decomposition and greenhouse gas emissions upon permafrost thawing. Attention to their functional genes is therefore essential to predict potential soil-climate feedbacks to the future warmer climate.
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Affiliation(s)
- Ciro Sannino
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy
| | - Weihong Qi
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
- Swiss Institute of Bioinformatics SIB, Geneva, Switzerland
| | - Joel Rüthi
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Beat Stierli
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland.
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Pastore MA, Classen AT, English ME, Frey SD, Knorr MA, Rand K, Adair EC. Soil microbial legacies influence freeze–thaw responses of soil. Funct Ecol 2023. [DOI: 10.1111/1365-2435.14273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Melissa A. Pastore
- Rubenstein School of Environment and Natural Resources University of Vermont Burlington Vermont USA
- Gund Institute for Environment University of Vermont Burlington Vermont USA
| | - Aimée T. Classen
- Gund Institute for Environment University of Vermont Burlington Vermont USA
- Ecology and Evolutionary Biology Department University of Michigan Ann Arbor Michigan USA
- University of Michigan Biological Station Pellston Michigan USA
| | - Marie E. English
- Rubenstein School of Environment and Natural Resources University of Vermont Burlington Vermont USA
| | - Serita D. Frey
- Department of Natural Resources and the Environment University of New Hampshire Durham New Hampshire USA
| | - Melissa A. Knorr
- Department of Natural Resources and the Environment University of New Hampshire Durham New Hampshire USA
| | - Karin Rand
- Rubenstein School of Environment and Natural Resources University of Vermont Burlington Vermont USA
| | - E. Carol Adair
- Rubenstein School of Environment and Natural Resources University of Vermont Burlington Vermont USA
- Gund Institute for Environment University of Vermont Burlington Vermont USA
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7
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Perez-Mon C, Stierli B, Plötze M, Frey B. Fast and persistent responses of alpine permafrost microbial communities to in situ warming. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150720. [PMID: 34610405 DOI: 10.1016/j.scitotenv.2021.150720] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/22/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Global warming in mid-latitude alpine regions results in permafrost thawing, together with greater availability of carbon and nutrients in soils and frequent freeze-thaw cycles. Yet it is unclear how these multifactorial changes will shape the 1 m-deep permafrost microbiome in the future, and how this will in turn modulate microbially-mediated feedbacks between mountain soils and climate (e.g. soil CO2 emissions). To unravel the responses of the alpine permafrost microbiome to in situ warming, we established a three-year experiment in a permafrost monitoring summit in the Alps. Specifically, we simulated conditions of warming by transplanting permafrost soils from a depth of 160 cm either to the active-layer topsoils in the north-facing slope or in the warmer south-facing slope, near the summit. qPCR-based and amplicon sequencing analyses indicated an augmented microbial abundance in the transplanted permafrost, driven by the increase in copiotrophic prokaryotic taxa (e.g. Noviherbaspirillum and Massilia) and metabolically versatile psychrotrophs (e.g. Tundrisphaera and Granulicella); which acclimatized to the changing environment and potentially benefited from substrates released upon thawing. Metabolically restricted Patescibacteria lineages vastly decreased with warming, as reflected in the loss of α-diversity in the transplanted soils. Ascomycetous sapro-pathotrophs (e.g. Tetracladium) and a few lichenized fungi (e.g. Aspicilia) expanded in the transplanted permafrost, particularly in soils transplanted to the warmer south-facing slope, replacing basidiomycetous yeasts (e.g. Glaciozyma). The transplantation-induced loosening of microbial association networks in the permafrost could potentially indicate lesser cooperative interactions between neighboring microorganisms. Broader substrate-use microbial activities measured in the transplanted permafrost could relate to altered soil C dynamics. The three-year simulated warming did not, however, enhance heterotrophic respiration, which was limited by the carbon-depleted permafrost conditions. Collectively, our quantitative findings suggest the vulnerability of the alpine permafrost microbiome to warming, which might improve predictions on microbially-modulated transformations of mountain soil ecosystems under the future climate.
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Affiliation(s)
- Carla Perez-Mon
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Beat Stierli
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Michael Plötze
- Institute for Geotechnical Engineering, ETH Zurich, Zurich, Switzerland
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland.
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Schreckinger J, Mutz M, Mendoza-Lera C, Frossard A. Attributes of Drying Define the Structure and Functioning of Microbial Communities in Temperate Riverbed Sediment. Front Microbiol 2021; 12:676615. [PMID: 34194411 PMCID: PMC8236957 DOI: 10.3389/fmicb.2021.676615] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/19/2021] [Indexed: 01/04/2023] Open
Abstract
Combined effects of climate change and increasing anthropogenic water demand have increased and extended dry period occurrences in rivers worldwide. Riverbed drying can significantly affect sediment microorganisms, crucial drivers of biogeochemical processes in lotic systems. In this study, we evaluated how sediment bacterial and fungal community structure and composition (based on 16S rRNA gene and ITS metabarcoding) and microbial functions (community respiration and extracellular enzymatic activities) respond to different riverbed drying intensities over 90 days. Riverbed sediment collected in a flowing reach of the Spree river in northeastern Germany was dried under different rates in outdoor mesocosms during the summer months of 2018. Our results demonstrate that drying attributes (duration and intensity) and sediment organic matter (OM) content play a crucial role in sediment microbial community assembly and functioning throughout drying. Milder drying surprisingly triggered a more rapid and drastic change in the microbial community composition and diversity. After 90 days of drying, Bacilli (Firmicutes) became the dominant bacterial class in most treatments, except in sediments with low OM content under the most severe drying treatment. Fungal amplicon sequence variants (ASVs) from Dothideomycetes (Ascomycota) had by far the highest relative abundance in all our treatments at the end of the drying experiment, making up 65.1% to 94.0% of the fungal reads. CO2 fluxes, a proxy for sediment community respiration, were rapidly and strongly affected by drying in all treatments. Our results imply that even short riverbed drying periods are likely to have significant consequences for the biogeochemical dynamics in recently formed non-perennial temperate rivers.
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Affiliation(s)
- José Schreckinger
- Department of Freshwater Conservation, Brandenburg University of Technology Cottbus-Senftenberg, Bad Saarow, Germany
| | - Michael Mutz
- Department of Freshwater Conservation, Brandenburg University of Technology Cottbus-Senftenberg, Bad Saarow, Germany
| | - Clara Mendoza-Lera
- Institute of Environmental Sciences, Koblenz-Landau University, Landau, Germany
| | - Aline Frossard
- Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Birmensdorf, Switzerland
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Frey B, Walthert L, Perez-Mon C, Stierli B, Köchli R, Dharmarajah A, Brunner I. Deep Soil Layers of Drought-Exposed Forests Harbor Poorly Known Bacterial and Fungal Communities. Front Microbiol 2021; 12:674160. [PMID: 34025630 PMCID: PMC8137989 DOI: 10.3389/fmicb.2021.674160] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/12/2021] [Indexed: 12/31/2022] Open
Abstract
Soil microorganisms such as bacteria and fungi play important roles in the biogeochemical cycling of soil nutrients, because they act as decomposers or are mutualistic or antagonistic symbionts, thereby influencing plant growth and health. In the present study, we investigated the vertical distribution of the soil microbiome to a depth of 2 m in Swiss drought-exposed forests of European beech and oaks on calcareous bedrock. We aimed to disentangle the effects of soil depth, tree (beech, oak), and substrate (soil, roots) on microbial abundance, diversity, and community structure. With increasing soil depth, organic carbon, nitrogen, and clay content decreased significantly. Similarly, fine root biomass, microbial biomass (DNA content, fungal abundance), and microbial alpha-diversity decreased and were consequently significantly related to these physicochemical parameters. In contrast, bacterial abundance tended to increase with soil depth, and the bacteria to fungi ratio increased significantly with greater depth. Tree species was only significantly related to the fungal Shannon index but not to the bacterial Shannon index. Microbial community analyses revealed that bacterial and fungal communities varied significantly across the soil layers, more strongly for bacteria than for fungi. Both communities were also significantly affected by tree species and substrate. In deep soil layers, poorly known bacterial taxa from Nitrospirae, Chloroflexi, Rokubacteria, Gemmatimonadetes, Firmicutes and GAL 15 were overrepresented. Furthermore, archaeal phyla such as Thaumarchaeota and Euryarchaeota were more abundant in subsoils than topsoils. Fungal taxa that were predominantly found in deep soil layers belong to the ectomycorrhizal Boletus luridus and Hydnum vesterholtii. Both taxa are reported for the first time in such deep soil layers. Saprotrophic fungal taxa predominantly recorded in deep soil layers were unknown species of Xylaria. Finally, our results show that the microbial community structure found in fine roots was well represented in the bulk soil. Overall, we recorded poorly known bacterial and archaeal phyla, as well as ectomycorrhizal fungi that were not previously known to colonize deep soil layers. Our study contributes to an integrated perspective on the vertical distribution of the soil microbiome at a fine spatial scale in drought-exposed forests.
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Affiliation(s)
- Beat Frey
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Lorenz Walthert
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Carla Perez-Mon
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Beat Stierli
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Roger Köchli
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Alexander Dharmarajah
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Ivano Brunner
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
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10
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Borowik A, Wyszkowska J, Kucharski J. Microbiological Study in Petrol-Spiked Soil. Molecules 2021; 26:2664. [PMID: 34062889 PMCID: PMC8125633 DOI: 10.3390/molecules26092664] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 12/23/2022] Open
Abstract
The pollution of arable lands and water with petroleum-derived products is still a valid problem, mainly due the extensive works aimed to improve their production technology to reduce fuel consumption and protect engines. An example of the upgraded fuels is the BP 98 unleaded petrol with Active technology. A pot experiment was carried out in which Eutric Cambisol soil was polluted with petrol to determine its effect on the microbiological and biochemical properties of this soil. Analyses were carried out to determine soil microbiome composition-with the incubation and metagenomic methods, the activity of seven enzymes, and cocksfoot effect on hydrocarbon degradation. The following indices were determined: colony development index (CD); ecophysiological diversity index (EP); index of cocksfoot effect on soil microorganisms and enzymes (IFG); index of petrol effect on soil microorganisms and enzymes (IFP); index of the resistance of microorganisms, enzymes, and cocksfoot to soil pollution with petrol (RS); Shannon-Weaver's index of bacterial taxa diversity (H); and Shannon-Weaver's index of hydrocarbon degradation (IDH). The soil pollution with petrol was found to increase population numbers of bacteria and fungi, and Protebacteria phylum abundance as well as to decrease the abundance of Actinobacteria and Acidobacteria phyla. The cultivation of cocksfoot on the petrol-polluted soil had an especially beneficial effect mainly on the bacteria belonging to the Ramlibacter, Pseudoxanthomonas, Mycoplana, and Sphingobium genera. The least susceptible to the soil pollution with petrol and cocksfoot cultivation were the bacteria of the following genera: Kaistobacter, Rhodoplanes, Bacillus, Streptomyces, Paenibacillus, Phenylobacterium, and Terracoccus. Cocksfoot proved effective in the phytoremediation of petrol-polluted soil, as it accelerated hydrocarbon degradation and increased the genetic diversity of bacteria. It additionally enhanced the activities of soil enzymes.
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Affiliation(s)
| | - Jadwiga Wyszkowska
- Department of Soil Science and Microbiology, University of Warmia and Mazury in Olsztyn, 10-727 Olsztyn, Poland; (A.B.); (J.K.)
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11
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Donhauser J, Qi W, Bergk-Pinto B, Frey B. High temperatures enhance the microbial genetic potential to recycle C and N from necromass in high-mountain soils. GLOBAL CHANGE BIOLOGY 2021; 27:1365-1386. [PMID: 33336444 DOI: 10.1111/gcb.15492] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/28/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Climate change is strongly affecting high-mountain soils and warming in particular is associated with pronounced changes in microbe-mediated C and N cycling, affecting plant-soil interactions and greenhouse gas balances and therefore feedbacks to global warming. We used shotgun metagenomics to assess changes in microbial community structures, as well as changes in microbial C- and N-cycling potential and stress response genes and we linked these data with changes in soil C and N pools and temperature-dependent measurements of bacterial growth rates. We did so by incubating high-elevation soil from the Swiss Alps at 4°C, 15°C, 25°C, or 35°C for 1 month. We found no shift with increasing temperature in the C-substrate-degrader community towards taxa more capable of degrading recalcitrant organic matter. Conversely, at 35°C, we found an increase in genes associated with the degradation and modification of microbial cell walls, together with high bacterial growth rates. Together, these findings suggest that the rapidly growing high-temperature community is fueled by necromass from heat-sensitive taxa. This interpretation was further supported by a shift in the microbial N-cycling potential towards N mineralization and assimilation under higher temperatures, along with reduced potential for conversions among inorganic N forms. Microbial stress-response genes reacted inconsistently to increasing temperature, suggesting that the high-temperature community was not severely stressed by these conditions. Rather, soil microbes were able to acclimate by changing the thermal properties of membranes and cell walls as indicated by an increase in genes involved in membrane and cell wall modifications as well as a shift in the optimum temperature for bacterial growth towards the treatment temperature. Overall, our results suggest that high temperatures, as they may occur with heat waves under global warming, promote a highly active microbial community capable of rapid mineralization of microbial necromass, which may transiently amplify warming effects.
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Affiliation(s)
- Jonathan Donhauser
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Weihong Qi
- Functional Genomics Center Zurich, ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Benoît Bergk-Pinto
- Environmental Microbial Genomics, Laboratoire Ampère, École Centrale de Lyon, Université de Lyon, Ecully, France
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
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Adamczyk M, Rüthi J, Frey B. Root exudates increase soil respiration and alter microbial community structure in alpine permafrost and active layer soils. Environ Microbiol 2021; 23:2152-2168. [PMID: 33393203 DOI: 10.1111/1462-2920.15383] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022]
Abstract
Due to climate warming, alpine ecosystems are changing rapidly. Ongoing upward migrations of plants and thus an increase of easily decomposable substrates will strongly affect the soil microbiome. To understand how belowground communities will respond to such changes, we set up an incubation experiment with permafrost and active soil layers from northern (NW) and southern (SE) slopes of a mountain ridge on Muot da Barba Peider in the Swiss Alps and incubated them with or without artificial root exudates (AREs) at two temperatures, 4°C or 15°C. The addition of AREs resulted in elevated respiration across all soil types. Bacterial and fungal alpha diversity decreased significantly, coinciding with strong shifts in microbial community structure in ARE-treated soils. These shifts in bacterial community structure were driven by an increased abundance of fast-growing copiotrophic taxa. Fungal communities were predominantly affected by AREs in SE active layer soils and shifted towards fast-growing opportunistic yeast. In contrast, in the colder NW facing active layer and permafrost soils fungal communities were more influenced by temperature changes. These findings demonstrate the sensitivity of soil microbial communities in high alpine ecosystems to climate change and how shifts in these communities may lead to functional changes impacting biogeochemical processes.
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Affiliation(s)
- Magdalene Adamczyk
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland
| | - Joel Rüthi
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland
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