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Chakraborty N, Halder S, Keswani C, Vaca J, Ortiz A, Sansinenea E. New Aspects of the Effects of Climate Change on Interactions Between Plants and Microbiomes: A Review. J Basic Microbiol 2024:e2400345. [PMID: 39205430 DOI: 10.1002/jobm.202400345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 07/15/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024]
Abstract
One of the most talked about issues of the 21st century is climate change, as it affects not just our health but also forestry, agriculture, biodiversity, the ecosystem, and the energy supply. Greenhouse gases are the primary cause of climate change, having dramatic effects on the environment. Climate change has an impact on the function and composition of the terrestrial microbial community both directly and indirectly. Changes in the prevailing climatic conditions brought about by climate change will lead to modifications in plant physiology, root exudation, signal alteration, and the quantity, makeup, and diversity of soil microbial communities. Microbiological activity is very crucial in organic production systems due to the organic origin of microorganisms. Microbes that benefit crop plants are known as plant growth-promoting microorganisms. Thus, the effects of climate change on the environment also have an impact on the abilities of beneficial bacteria to support plant growth, health, and root colonization. In this review, we have covered the effects of temperature, precipitation, drought, and CO2 on plant-microbe interactions, as well as some physiological implications of these changes. Additionally, this paper highlights the ways in which bacteria in plants' rhizosphere react to the dominant climatic conditions in the soil environment. The goal of this study is to analyze the effects of climate change on plant-microbe interactions.
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Affiliation(s)
- Nilanjan Chakraborty
- Department of Botany, Scottish Church College, University of Calcutta, Kolkata, India
| | - Sunanda Halder
- Department of Botany, Scottish Church College, University of Calcutta, Kolkata, India
| | - Chetan Keswani
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Jessica Vaca
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Aurelio Ortiz
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Estibaliz Sansinenea
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, México
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Black ME, Fei C, Alert R, Wingreen NS, Shaevitz JW. Capillary interactions drive the self-organization of bacterial colonies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596252. [PMID: 38853967 PMCID: PMC11160631 DOI: 10.1101/2024.05.28.596252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Many bacteria inhabit thin layers of water on solid surfaces both naturally in soils or on hosts or textiles and in the lab on agar hydrogels. In these environments, cells experience capillary forces, yet an understanding of how these forces shape bacterial collective behaviors remains elusive. Here, we show that the water menisci formed around bacteria lead to capillary attraction between cells while still allowing them to slide past one another. We develop an experimental apparatus that allows us to control bacterial collective behaviors by varying the strength and range of capillary forces. Combining 3D imaging and cell tracking with agent-based modeling, we demonstrate that capillary attraction organizes rod-shaped bacteria into densely packed, nematic groups, and profoundly influences their collective dynamics and morphologies. Our results suggest that capillary forces may be a ubiquitous physical ingredient in shaping microbial communities in partially hydrated environments.
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Zhang T, Zhang D, Lyu Z, Zhang J, Wu X, Yu Y. Effects of extreme precipitation on bacterial communities and bioaerosol composition: Dispersion in urban outdoor environments and health risks. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 344:123406. [PMID: 38244904 DOI: 10.1016/j.envpol.2024.123406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/22/2024]
Abstract
Concerns about contaminants dispersed by seasonal precipitation have grown due to their potential hazards to outdoor environments and human health. However, studies on the crucial environmental factors influencing dispersion changes in bacterial communities are limited. This research adopted four-season in situ monitoring and sequencing techniques to examine the regional distribution profiles of bioaerosols, bacterial communities, and risks associated with extreme snowfall versus rainfall events in two monsoon cities. In the early-hours of winter snowfall, airborne cultivable bioaerosol concentrations were 4.1 times higher than the reference exposure limit (500 CFU/m3). The concentration of ambient particles (2.5 μm) exceeded 24,910 particles/L (97 μg/m3), positively correlating with the prevalence of cultivable bioaerosols. These bioaerosols contained cultivable bacterial species such as pathogenic Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Escherichia coli. Bioaerosol concentrations increased by 53.0% during 50-mm snow extremes. Taxonomic analysis revealed that Pseudomonas, Staphylococcus, and Veillonella were the most abundant bacterial taxa in the initial snowmelt samples during winter precipitation. However, their abundance decreased by 87.6% as snowing continued (24 h). Reduced water base cation concentration also led to a 1.15-fold increase in the Shannon index, indicating a similar yet heightened bacterial diversity. Seasonally, Pedobacter and Massilia showed higher relative abundance (25% and 18%, respectively), presenting increased bacterial transmission to the soil. Furthermore, Pseudomonas was identified in 60% of spring snowstorm samples, suggesting long-distance dispersal of pathogenic bacteria. When these atmospheric aerosol particles carrying biological entities (0.65-1.1 μm) penetrated human alveoli, the calculated hazard ratio was 0.55, which as observed in inhalation exposures. Consequently, this study underscores the risk of seasonal precipitation-enhanced ambient bacterial transmission.
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Affiliation(s)
- Ting Zhang
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Dingqiang Zhang
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Zhonghang Lyu
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Jitao Zhang
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Xian Wu
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Yingxin Yu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
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Rodríguez V, Bartholomäus A, Witzgall K, Riveras-Muñoz N, Oses R, Liebner S, Kallmeyer J, Rach O, Mueller CW, Seguel O, Scholten T, Wagner D. Microbial impact on initial soil formation in arid and semiarid environments under simulated climate change. Front Microbiol 2024; 15:1319997. [PMID: 38298893 PMCID: PMC10827993 DOI: 10.3389/fmicb.2024.1319997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/02/2024] [Indexed: 02/02/2024] Open
Abstract
The microbiota is attributed to be important for initial soil formation under extreme climate conditions, but experimental evidence for its relevance is scarce. To fill this gap, we investigated the impact of in situ microbial communities and their interrelationship with biocrust and plants compared to abiotic controls on soil formation in initial arid and semiarid soils. Additionally, we assessed the response of bacterial communities to climate change. Topsoil and subsoil samples from arid and semiarid sites in the Chilean Coastal Cordillera were incubated for 16 weeks under diurnal temperature and moisture variations to simulate humid climate conditions as part of a climate change scenario. Our findings indicate that microorganism-plant interaction intensified aggregate formation and stabilized soil structure, facilitating initial soil formation. Interestingly, microorganisms alone or in conjunction with biocrust showed no discernible patterns compared to abiotic controls, potentially due to water-masking effects. Arid soils displayed reduced bacterial diversity and developed a new community structure dominated by Proteobacteria, Actinobacteriota, and Planctomycetota, while semiarid soils maintained a consistently dominant community of Acidobacteriota and Proteobacteria. This highlighted a sensitive and specialized bacterial community in arid soils, while semiarid soils exhibited a more complex and stable community. We conclude that microorganism-plant interaction has measurable impacts on initial soil formation in arid and semiarid regions on short time scales under climate change. Additionally, we propose that soil and climate legacies are decisive for the present soil microbial community structure and interactions, future soil development, and microbial responses.
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Affiliation(s)
- Victoria Rodríguez
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany
| | | | - Kristina Witzgall
- Soil Science, TUM School of Life Sciences, Technical University of Munich, Freising-Weihenstephan, Germany
| | - Nicolás Riveras-Muñoz
- Department of Geosciences, Soil Science and Geomorphology, University of Tübingen, Tübingen, Germany
| | - Romulo Oses
- Centro Regional de Investigación y Desarrollo Sustentable de Atacama (CRIDESAT), Universidad de Atacama, Copiapó, Chile
| | - Susanne Liebner
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Jens Kallmeyer
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany
| | - Oliver Rach
- GFZ German Research Centre for Geosciences, Section Geomorphology, Potsdam, Germany
| | - Carsten W. Mueller
- Institute for Ecology, Chair of Soil Science, Technische Universitaet Berlin, Berlin, Germany
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Oscar Seguel
- Facultad de Ciencias Agronómicas, Universidad de Chile, Santiago, Chile
| | - Thomas Scholten
- Department of Geosciences, Soil Science and Geomorphology, University of Tübingen, Tübingen, Germany
| | - Dirk Wagner
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany
- Institute of Geosciences, University of Potsdam, Potsdam, Germany
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Giorgio M, Niccolò BGM, Benedetta T, Luisa M, Leonardo BF, Gregory B, Pietro B, Alberto A, Domizia D, Emidio A. Fungal and Bacterial Diversity in the Tuber magnatum Ecosystem and Microbiome. MICROBIAL ECOLOGY 2023; 85:508-521. [PMID: 35237850 DOI: 10.1007/s00248-021-01950-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Fungi belonging to the genus Tuber produce edible ascocarps known as truffles. Tuber magnatum Picco may be the most appreciated truffle species given its peculiar aroma. While its life cycle is not yet fully elucidated, some studies demonstrated an active role of microorganisms. The main goal of this study was to determine how the T. magnatum microbiome varies across space and time. To address this, we characterized microbial communities associated with T. magnatum through high-throughput amplicon sequencing of internal transcribed spacer (ITS) and 16S rDNAs in three productive natural sites in Italy across 2 years. At each site, four truffles were sampled as well as the soil underneath and at 40, 100, and 200 cm from the harvesting points, to assess for microbial variation between substrates, years, and sites. A statistically significant site-related effect on microbial communities was identified, whereas only the prokaryotic community was significantly affected by the distance of soil from the truffle. Significant differences between sampling years were also found, demonstrating a possible relation among rainfall precipitation and Firmicutes and Actinobacteria. Thirty-six bacterial OTUs in truffles and 11 bacterial OTUs in soils beneath truffles were identified as indicator taxa. As shown for other truffle species, the dominance of Bradyrhizobium, Rhizobium, and Ensifer spp. within the truffle fruiting body suggests an evolutionary adaptation of this microorganism to the genus Tuber. The present work offers novel and relevant insights into the microbial ecology of T. magnatum ecosystems and fruiting bodies. The function and role of these bacteria in the truffle microbiome and life cycle are in need of further investigation.
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Affiliation(s)
- Marozzi Giorgio
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121, Perugia, Italy
| | - Benucci Gian Maria Niccolò
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA.
| | - Turchetti Benedetta
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121, Perugia, Italy
| | - Massaccesi Luisa
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, 01100, Viterbo, Italy
| | - Baciarelli Falini Leonardo
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121, Perugia, Italy
| | - Bonito Gregory
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - Buzzini Pietro
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121, Perugia, Italy
| | - Agnelli Alberto
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121, Perugia, Italy
| | - Donnini Domizia
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121, Perugia, Italy
| | - Albertini Emidio
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121, Perugia, Italy
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Kuhn T, Mamin M, Bindschedler S, Bshary R, Estoppey A, Gonzalez D, Palmieri F, Junier P, Richter XYL. Spatial scales of competition and a growth-motility trade-off interact to determine bacterial coexistence. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211592. [PMID: 36483758 PMCID: PMC9727664 DOI: 10.1098/rsos.211592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
The coexistence of competing species is a long-lasting puzzle in evolutionary ecology research. Despite abundant experimental evidence showing that the opportunity for coexistence decreases as niche overlap increases between species, bacterial species and strains competing for the same resources are commonly found across diverse spatially heterogeneous habitats. We thus hypothesized that the spatial scale of competition may play a key role in determining bacterial coexistence, and interact with other mechanisms that promote coexistence, including a growth-motility trade-off. To test this hypothesis, we let two Pseudomonas putida strains compete at local and regional scales by inoculating them either in a mixed droplet or in separate droplets in the same Petri dish, respectively. We also created conditions that allow the bacterial strains to disperse across abiotic or fungal hyphae networks. We found that competition at the local scale led to competitive exclusion while regional competition promoted coexistence. When competing in the presence of dispersal networks, the growth-motility trade-off promoted coexistence only when the strains were inoculated in separate droplets. Our results provide a mechanism by which existing laboratory data suggesting competitive exclusion at a local scale is reconciled with the widespread coexistence of competing bacterial strains in complex natural environments with dispersal.
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Affiliation(s)
- Thierry Kuhn
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
- Laboratory of Eco-Ethology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Marine Mamin
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Saskia Bindschedler
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Redouan Bshary
- Laboratory of Eco-Ethology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Aislinn Estoppey
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Diego Gonzalez
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Fabio Palmieri
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Pilar Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Xiang-Yi Li Richter
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
- Laboratory of Eco-Ethology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
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7
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Liu Y, Luo W, Wen X, Mu G, Wu X, Zhang Z. Eco-Stoichiometric Characteristics of Rhizosphere and Bulk Soils of Smilax china L. along Vertical Zone Spectrum of Fanjing Mountain. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19148693. [PMID: 35886545 PMCID: PMC9319539 DOI: 10.3390/ijerph19148693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/27/2022] [Accepted: 07/05/2022] [Indexed: 12/04/2022]
Abstract
To explore the correlations between nutrients and stoichiometric characteristics in the rhizosphere and bulk soils of understory Smilax china L. in forest ecosystems at different altitudes and to clarify the rhizosphere effect of understory vegetation in forest ecosystems and its response strategy to altitude, providing a theoretical basis for better forest ecological environment protection and high-quality development in Fanjing Mountain. Understory Smilax china L. at four different altitudes were selected, with the differences and influencing factors of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) mass fractions and stoichiometric ratios in their rhizosphere and bulk soils analyzed. The average mass fractions of total C, total N and alkali-hydrolyzed N in the rhizosphere and bulk soils of Smilax china L. at different altitudes were 224.43 and 181.55 g·kg−1; 9.56 and 6.81 g·kg−1; and 648.19 and 600.70 g·kg−1, respectively. The rhizosphere effect of Smilax china L. was significant at altitudes of 500 m and 1000 m but became not so prominent with the rise of altitude. The C:N ratio in the rhizosphere and bulk soils ranged from 19.51 to 39.75 and the C:P ratio ranged from 225.29 to 543.05. C accumulation is greater than N accumulation in the rhizosphere and bulk soils of Smilax china L., and both present P limitation. Based on the comprehensive analysis of the mass fractions and eco-stoichiometric ratios of soil nutrients, the P limitation in Fanjing Mountain forest ecosystem is commonly seen and should be addressed.
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Affiliation(s)
- Yingying Liu
- Guizhou Institute of Biology, Guiyang 550009, China; (Y.L.); (W.L.); (G.M.); (X.W.)
| | - Wenmin Luo
- Guizhou Institute of Biology, Guiyang 550009, China; (Y.L.); (W.L.); (G.M.); (X.W.)
| | - Ximei Wen
- Guizhou Institute of Mountain Resources, Guiyang 550002, China;
| | - Guiting Mu
- Guizhou Institute of Biology, Guiyang 550009, China; (Y.L.); (W.L.); (G.M.); (X.W.)
| | - Xianliang Wu
- Guizhou Institute of Biology, Guiyang 550009, China; (Y.L.); (W.L.); (G.M.); (X.W.)
| | - Zhenming Zhang
- Guizhou Institute of Biology, Guiyang 550009, China; (Y.L.); (W.L.); (G.M.); (X.W.)
- Correspondence: ; Tel.: +86-151-8519-6301
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Diaz-Garza AM, Fierro-Rivera JI, Pacheco A, Schüßler A, Gradilla-Hernández MS, Senés-Guerrero C. Temporal Dynamics of Rhizobacteria Found in Pequin Pepper, Soybean, and Orange Trees Growing in a Semi-arid Ecosystem. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.602283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Jordaan K, Lappan R, Dong X, Aitkenhead IJ, Bay SK, Chiri E, Wieler N, Meredith LK, Cowan DA, Chown SL, Greening C. Hydrogen-Oxidizing Bacteria Are Abundant in Desert Soils and Strongly Stimulated by Hydration. mSystems 2020; 5:e01131-20. [PMID: 33203691 PMCID: PMC7677003 DOI: 10.1128/msystems.01131-20] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 01/19/2023] Open
Abstract
How the diverse bacterial communities inhabiting desert soils maintain energy and carbon needs is much debated. Traditionally, most bacteria are thought to persist by using organic carbon synthesized by photoautotrophs following transient hydration events. Recent studies focused on Antarctic desert soils have revealed, however, that some bacteria use atmospheric trace gases, such as hydrogen (H2), to conserve energy and fix carbon independently of photosynthesis. In this study, we investigated whether atmospheric H2 oxidation occurs in four nonpolar desert soils and compared this process to photosynthesis. To do so, we first profiled the distribution, expression, and activities of hydrogenases and photosystems in surface soils collected from the South Australian desert over a simulated hydration-desiccation cycle. Hydrogenase-encoding sequences were abundant in the metagenomes and metatranscriptomes and were detected in actinobacterial, acidobacterial, and cyanobacterial metagenome-assembled genomes. Native dry soil samples mediated H2 oxidation, but rates increased 950-fold following wetting. Oxygenic and anoxygenic phototrophs were also detected in the community but at lower abundances. Hydration significantly stimulated rates of photosynthetic carbon fixation and, to a lesser extent, dark carbon assimilation. Hydrogenase genes were also widespread in samples from three other climatically distinct deserts, the Namib, Gobi, and Mojave, and atmospheric H2 oxidation was also greatly stimulated by hydration at these sites. Together, these findings highlight that H2 is an important, hitherto-overlooked energy source supporting bacterial communities in desert soils. Contrary to our previous hypotheses, however, H2 oxidation occurs simultaneously rather than alternately with photosynthesis in such ecosystems and may even be mediated by some photoautotrophs.IMPORTANCE Desert ecosystems, spanning a third of the earth's surface, harbor remarkably diverse microbial life despite having a low potential for photosynthesis. In this work, we reveal that atmospheric hydrogen serves as a major previously overlooked energy source for a large proportion of desert bacteria. We show that both chemoheterotrophic and photoautotrophic bacteria have the potential to oxidize hydrogen across deserts sampled across four continents. Whereas hydrogen oxidation was slow in native dry deserts, it increased by three orders of magnitude together with photosynthesis following hydration. This study revealed that continual harvesting of atmospheric energy sources may be a major way that desert communities adapt to long periods of water and energy deprivation, with significant ecological and biogeochemical ramifications.
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Affiliation(s)
- Karen Jordaan
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Rachael Lappan
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Xiyang Dong
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, China
| | - Ian J Aitkenhead
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - Sean K Bay
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Eleonora Chiri
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | | | - Laura K Meredith
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, USA
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Steven L Chown
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
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10
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Rapid Shifts in Bacterial Community Assembly under Static and Dynamic Hydration Conditions in Porous Media. Appl Environ Microbiol 2019; 86:AEM.02057-19. [PMID: 31653789 PMCID: PMC6912082 DOI: 10.1128/aem.02057-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 10/04/2019] [Indexed: 11/26/2022] Open
Abstract
The composition and activity of soil bacteria are central to various ecosystem services and soil biogeochemical cycles. A key factor for soil bacterial activity is soil hydration, which is in a constant state of change due to rainfall, drainage, plant water uptake, and evaporation. These dynamic changes in soil hydration state affect the structure and function of soil bacterial communities in complex ways often unobservable in natural soil. We designed an experimental system that retains the salient features of hydrated soil yet enables systematic evaluation of changes in a representative bacterial community in response to cycles of wetting and drying. The study shows that hydration cycles affect community abundance, yet most changes in composition occur with the less-abundant species (while the successful ones remain dominant). This research offers a new path for an improved understanding of bacterial community assembly in natural environments, including bacterial growth, maintenance, and death, with a special focus on the role of hydrological factors. The complexity of natural soils presents a challenge to the systematic identification and disentanglement of governing processes that shape natural bacterial communities. Studies have highlighted the critical role of the soil aqueous phase in shaping interactions among soil bacterial communities. To quantify and improve the attributability of soil aqueous-phase effects, we introduced a synthetic and traceable bacterial community to simple porous microcosms and subjected the community to constant or dynamic hydration conditions. The results were expressed in terms of absolute abundance and show species-specific responses to hydration and nutrient conditions. Hydration dynamics exerted a significant influence on the fraction of less-abundant species, especially after extended incubation periods. Phylogenetic relationships did not explain the group of most abundant species. The ability to quantify species-level dynamics in a bacterial community offers an important step toward deciphering the links between community composition and functions in dynamic terrestrial environments. IMPORTANCE The composition and activity of soil bacteria are central to various ecosystem services and soil biogeochemical cycles. A key factor for soil bacterial activity is soil hydration, which is in a constant state of change due to rainfall, drainage, plant water uptake, and evaporation. These dynamic changes in soil hydration state affect the structure and function of soil bacterial communities in complex ways often unobservable in natural soil. We designed an experimental system that retains the salient features of hydrated soil yet enables systematic evaluation of changes in a representative bacterial community in response to cycles of wetting and drying. The study shows that hydration cycles affect community abundance, yet most changes in composition occur with the less-abundant species (while the successful ones remain dominant). This research offers a new path for an improved understanding of bacterial community assembly in natural environments, including bacterial growth, maintenance, and death, with a special focus on the role of hydrological factors.
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