1
|
Tolotti M, Brighenti S, Bruno MC, Cerasino L, Pindo M, Tirler W, Albanese D. Ecological "Windows of opportunity" influence biofilm prokaryotic diversity differently in glacial and non-glacial Alpine streams. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 944:173826. [PMID: 38866149 DOI: 10.1016/j.scitotenv.2024.173826] [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: 02/11/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 06/14/2024]
Abstract
In glacier-fed streams, the Windows of Opportunity (WOs) are periods of mild environmental conditions supporting the seasonal development of benthic microorganisms. WOs have been defined based on changes in biofilm biomass, but the responses of microbial diversity to WOs in Alpine streams have been overlooked. A two year (2017-2018) metabarcoding of epilithic and epipsammic biofilm prokaryotes was conducted in Alpine streams fed by glaciers (kryal), rock glaciers (rock glacial), or groundwater/precipitation (krenal) in two catchments of the Central-Eastern European Alps (Italy), aiming at testing the hypothesis that: 1) environmental WOs enhance not only the biomass but also the α-diversity of the prokaryotic biofilm in all stream types, 2) diversity and phenology of prokaryotic biofilm are mainly influenced by the physical habitat in glacial streams, and by water chemistry in the other two stream types. The study confirmed kryal and krenal streams as endmembers of epilithic and sediment prokaryotic α- and β-diversity, with rock glacial streams sharing a large proportion of taxa with the two other stream types. Alpha-diversity appeared to respond to ecological WOs, but, contrary to expectations, seasonality was less pronounced in the turbid kryal than in the clear streams. This was attributed to the small size of the glaciers feeding the studied kryal streams, whose discharge dynamics were those typical of the late phase of deglaciation. Prokaryotic α-diversity of non-glacial streams tended to be higher in early summer than in early autumn. Our findings, while confirming that high altitude streams are heavily threatened by climate change, underscore the still neglected role of rock glacier runoffs as climate refugia for the most stenothermic benthic aquatic microorganism. This advocates the need to define and test strategies for protecting these ecosystems for preserving, restoring, and connecting cold Alpine aquatic biodiversity in the context of the progressing global warming.
Collapse
Affiliation(s)
- Monica Tolotti
- Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all'Adige, Italy; National Biodiversity Future Center (NBFC), Università di Palermo, Palermo, Italy.
| | - Stefano Brighenti
- Competence Centre for Mountain Innovation Ecosystems, Free University of Bolzano, Bolzano/Bozen, Italy
| | - Maria Cristina Bruno
- Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all'Adige, Italy; National Biodiversity Future Center (NBFC), Università di Palermo, Palermo, Italy
| | - Leonardo Cerasino
- Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all'Adige, Italy
| | - Massimo Pindo
- Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all'Adige, Italy
| | | | - Davide Albanese
- Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all'Adige, Italy
| |
Collapse
|
2
|
Sanyal A, Antony R, Samui G, Thamban M. Autotrophy to Heterotrophy: Shift in Bacterial Functions During the Melt Season in Antarctic Cryoconite Holes. J Microbiol 2024:10.1007/s12275-024-00140-1. [PMID: 38814540 DOI: 10.1007/s12275-024-00140-1] [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: 11/03/2023] [Revised: 03/27/2024] [Accepted: 04/23/2024] [Indexed: 05/31/2024]
Abstract
Microbes residing in cryoconite holes (debris, water, and nutrient-rich ecosystems) on the glacier surface actively participate in carbon and nutrient cycling. Not much is known about how these communities and their functions change during the summer melt-season when intense ablation and runoff alter the influx and outflux of nutrients and microbes. Here, we use high-throughput-amplicon sequencing, predictive metabolic tools and Phenotype MicroArray techniques to track changes in bacterial communities and functions in cryoconite holes in a coastal Antarctic site and the surrounding fjord, during the summer season. The bacterial diversity in cryoconite hole meltwater was predominantly composed of heterotrophs (Proteobacteria) throughout the season. The associated functional potentials were related to heterotrophic-assimilatory and -dissimilatory pathways. Autotrophic Cyanobacterial lineages dominated the debris community at the beginning and end of summer, while heterotrophic Bacteroidota- and Proteobacteria-related phyla increased during the peak melt period. Predictive functional analyses based on taxonomy show a shift from predominantly phototrophy-related functions to heterotrophic assimilatory pathways as the melt-season progressed. This shift from autotrophic to heterotrophic communities within cryoconite holes can affect carbon drawdown and nutrient liberation from the glacier surface during the summer. In addition, the flushing out and export of cryoconite hole communities to the fjord could influence the biogeochemical dynamics of the fjord ecosystem.
Collapse
Affiliation(s)
- Aritri Sanyal
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Goa, 403804, India.
- School of Earth, Ocean and Atmospheric Sciences, Goa University, Goa, 403206, India.
| | - Runa Antony
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Goa, 403804, India
- GFZ German Research Centre for Geosciences, 14473, Potsdam, Germany
| | - Gautami Samui
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Goa, 403804, India
- Department of Environmental Science, Savitribai Phule Pune University, Ganeshkhind, Pune, 411007, India
| | - Meloth Thamban
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Goa, 403804, India
| |
Collapse
|
3
|
Rassner SME, Cook JM, Mitchell AC, Stevens IT, Irvine-Fynn TDL, Hodson AJ, Edwards A. The distinctive weathering crust habitat of a High Arctic glacier comprises discrete microbial micro-habitats. Environ Microbiol 2024; 26:e16617. [PMID: 38558266 DOI: 10.1111/1462-2920.16617] [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: 12/08/2023] [Accepted: 03/08/2024] [Indexed: 04/04/2024]
Abstract
Sunlight penetrates the ice surfaces of glaciers and ice sheets, forming a water-bearing porous ice matrix known as the weathering crust. This crust is home to a significant microbial community. Despite the potential implications of microbial processes in the weathering crust for glacial melting, biogeochemical cycles, and downstream ecosystems, there have been few explorations of its microbial communities. In our study, we used 16S rRNA gene sequencing and shotgun metagenomics of a Svalbard glacier surface catchment to characterise the microbial communities within the weathering crust, their origins and destinies, and the functional potential of the weathering crust metagenome. Our findings reveal that the bacterial community in the weathering crust is distinct from those in upstream and downstream habitats. However, it comprises two separate micro-habitats, each with different taxa and functional categories. The interstitial porewater is dominated by Polaromonas, influenced by the transfer of snowmelt, and exported via meltwater channels. In contrast, the ice matrix is dominated by Hymenobacter, and its metagenome exhibits a diverse range of functional adaptations. Given that the global weathering crust area and the subsequent release of microbes from it are strongly responsive to climate projections for the rest of the century, our results underscore the pressing need to integrate the microbiome of the weathering crust with other communities and processes in glacial ecosystems.
Collapse
Affiliation(s)
| | - Joseph M Cook
- Department of Life Sciences, Aberystwyth University, Wales, UK
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Andrew C Mitchell
- Department of Geography and Earth Sciences, Aberystwyth University, Wales, UK
| | - Ian T Stevens
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
- Department of Geography and Earth Sciences, Aberystwyth University, Wales, UK
| | | | - Andrew J Hodson
- Department of Arctic Geology, University Centre in Svalbard (UNIS), Longyearbyen, Norway
| | - Arwyn Edwards
- Department of Life Sciences, Aberystwyth University, Wales, UK
- Department of Arctic Biology, University Centre in Svalbard (UNIS), Longyearbyen, Norway
| |
Collapse
|
4
|
Mukhia S, Kumar A, Kumar R. Bacterial community distribution and functional potentials provide key insights into their role in the ecosystem functioning of a retreating Eastern Himalayan glacier. FEMS Microbiol Ecol 2024; 100:fiae012. [PMID: 38305149 PMCID: PMC10876117 DOI: 10.1093/femsec/fiae012] [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: 09/03/2023] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 02/03/2024] Open
Abstract
Himalayan glaciers are receding at an exceptional rate, perturbing the local biome and ecosystem processes. Understanding the microbial ecology of an exclusively microbe-driven biome provides insights into their contributions to the ecosystem functioning through biogeochemical fluxes. Here, we investigated the bacterial communities and their functional potential in the retreating East Rathong Glacier (ERG) of Sikkim Himalaya. Amplicon-based taxonomic classification revealed the dominance of the phyla Proteobacteria, Bacteroidota, and candidate Patescibacteria in the glacial sites. Further, eight good-quality metagenome-assembled genomes (MAGs) of Proteobacteria, Patescibacteria, Acidobacteriota, and Choloflexota retrieved from the metagenomes elucidated the microbial contributions to nutrient cycling. The ERG MAGs showed aerobic respiration as a primary metabolic feature, accompanied by carbon fixation and complex carbon degradation potentials. Pathways for nitrogen metabolism, chiefly dissimilatory nitrate reduction and denitrification, and a complete sulphur oxidation enzyme complex for sulphur metabolism were identified in the MAGs. We observed that DNA repair and oxidative stress response genes complemented with osmotic and periplasmic stress and protein chaperones were vital for adaptation against the intense radiation and stress conditions of the extreme Himalayan niche. Current findings elucidate the microbiome and associated functional potentials of a vulnerable glacier, emphasizing their significant ecological roles in a changing glacial ecosystem.
Collapse
Affiliation(s)
- Srijana Mukhia
- Biotechnology Division, CSIR – Institute of Himalayan Bioresource Technology, Post Box No. 06, Palampur 176061, Himachal Pradesh, India
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Anil Kumar
- Biotechnology Division, CSIR – Institute of Himalayan Bioresource Technology, Post Box No. 06, Palampur 176061, Himachal Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Rakshak Kumar
- Biotechnology Division, CSIR – Institute of Himalayan Bioresource Technology, Post Box No. 06, Palampur 176061, Himachal Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
5
|
Ren Z, Gao H. Antibiotic resistance genes in integrated surface ice, cryoconite, and glacier-fed stream in a mountain glacier in Central Asia. ENVIRONMENT INTERNATIONAL 2024; 184:108482. [PMID: 38324929 DOI: 10.1016/j.envint.2024.108482] [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: 12/04/2023] [Revised: 01/16/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
Glacier ice, cryoconite, and glacier-fed streams are interconnected features that have important implications for the dynamics and distribution of abiotic and biotic materials. However, the presence and behavior of antibiotic resistance genes (ARGs) within these glacial environments remained largely unexplored. Addressing this gap, we hypothesized that ARGs are widely distributed and exhibit distinct yet interconnected patterns of diversity and dynamics in these glacial environments. Here, we investigated ARGs in a mountain glacier in Central Asia. A total of 944 ARGs, spanning 22 antibiotic classes, were identified, with 633 ARGs shared across all three environments. Cryoconite exhibited the highest ARG richness, followed by ice, while stream biofilm displayed the lowest value. Exploring ARG profiles, we observed a consistent pattern in terms of antibiotic class and resistance mechanism across all three environments. Beta-lactam resistance genes exhibited the highest diversity, followed by multidrug, glycopeptide, and MLS. The predominant mechanisms were antibiotic inactivation, antibiotic efflux, and target alteration. The most prevalent ARG is cls, followed by mdfA, ropB, fabI, and macB. The similarity in ARG profiles between surface ice and cryoconite samples was more pronounced than their resemblance to stream biofilm samples. The variations of ARG profiles between any pair of environments were largely contributed by turnover component. Further insights into microbial interactions revealed 2328 significant associations between 80 OTUs and 356 ARGs, indicating complex relationships. Certain OTUs, including those from the genera Polaromonas, Ferruginibacter, Hymenobacter, Phormidesmis, Novosphingobium, and Polymorphobacter, were speculated as potential hosts for a variety of ARGs. Our findings underscore the intricate dynamics of antibiotic resistance in glacial ecosystems, emphasizing the need for a holistic understanding of ARG distribution, diversity, and associations across diverse environmental compartments. This research contributes valuable insights into the potential ecological implications of antibiotic resistance dissemination in cold environments, particularly as influenced by increasing climate change.
Collapse
Affiliation(s)
- Ze Ren
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Hongkai Gao
- Key Laboratory of Geographic Information Science (Ministry of Education), East China Normal University, Shanghai 200241, China.
| |
Collapse
|
6
|
Zhang Z, Liu Y, Zhao W, Ji M. Radiation impacts gene redundancy and biofilm regulation of cryoconite microbiomes in Northern Hemisphere glaciers. MICROBIOME 2023; 11:228. [PMID: 37848997 PMCID: PMC10583317 DOI: 10.1186/s40168-023-01621-y] [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: 04/06/2023] [Accepted: 07/14/2023] [Indexed: 10/19/2023]
Abstract
BACKGROUND Glaciers harbor diverse microorganisms adapted to extreme conditions with high radiation, fluctuating temperature, and low nutrient availability. In glacial ecosystems, cryoconite granules are hotspots of microbial metabolic activity and could influences the biogeochemical cycle on glacier surface. Climate change could influence glacier dynamics by changing regional meteorological factors (e.g., radiation, precipitation, temperature, wind, and evaporation). Moreover, meteorological factors not only influence glacier dynamics but also directly or indirectly influence cryoconite microbiomes. However, the relationship of the meteorological factors and cryoconite microbiome are poorly understood. RESULTS Here, we collected 88 metagenomes from 26 glaciers distributed in the Northern Hemisphere with corresponding public meteorological data to reveal the relationship between meteorological factors and variation of cryoconite microbiome. Our results showed significant differences in taxonomic and genomic characteristics between cryoconite generalists and specialists. Additionally, we found that the biogeography of both generalists and specialists was influenced by solar radiation. Specialists with smaller genome size and lower gene redundancy were more abundant under high radiation stress, implying that streamlined genomes are more adapted to high radiation conditions. Network analysis revealed that biofilm regulation is a ubiquitous function in response to radiation stress, and hub genes were associated with the formation and dispersion of biofilms. CONCLUSION These findings enhance our understanding of glacier cryoconite microbiome variation on a hemispheric scale and indicate the response mechanisms to radiation stress, which will support forecasts of the ecological consequences of future climate change. Video Abstract.
Collapse
Affiliation(s)
- Zhihao Zhang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yongqin Liu
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Center for Pan-Third Pole Environment, Lanzhou University, Lanzhou, 730000, China.
| | - Weishu Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
- SJTU Yazhou Bay Institute of Deepsea Sci-Tech, Yongyou Industrial Park, Sanya, 572024, China
- International Center for Deep Life Investigation (IC-DLI), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Mukan Ji
- Center for Pan-Third Pole Environment, Lanzhou University, Lanzhou, 730000, China
| |
Collapse
|
7
|
Michoud G, Kohler TJ, Ezzat L, Peter H, Nattabi JK, Nalwanga R, Pramateftaki P, Styllas M, Tolosano M, De Staercke V, Schön M, Marasco R, Daffonchio D, Bourquin M, Busi SB, Battin TJ. The dark side of the moon: first insights into the microbiome structure and function of one of the last glacier-fed streams in Africa. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230329. [PMID: 37564072 PMCID: PMC10410210 DOI: 10.1098/rsos.230329] [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: 03/16/2023] [Accepted: 06/20/2023] [Indexed: 08/12/2023]
Abstract
The glaciers on Africa's 'Mountains of the Moon' (Rwenzori National Park, Uganda) are predicted to disappear within the next decades owing to climate change. Consequently, the glacier-fed streams (GFSs) that drain them will vanish, along with their resident microbial communities. Despite the relevance of microbial communities for performing ecosystem processes in equatorial GFSs, their ecology remains understudied. Here, we show that the benthic microbiome from the Mt. Stanley GFS is distinct at several levels from other GFSs. Specifically, several novel taxa were present, and usually common groups such as Chrysophytes and Polaromonas exhibited lower relative abundances compared to higher-latitude GFSs, while cyanobacteria and diatoms were more abundant. The rich primary producer community in this GFS likely results from the greater environmental stability of the Afrotropics, and accordingly, heterotrophic processes dominated in the bacterial community. Metagenomics revealed that almost all prokaryotes in the Mt. Stanley GFS are capable of organic carbon oxidation, while greater than 80% have the potential for fermentation and acetate oxidation. Our findings suggest a close coupling between photoautotrophs and other microbes in this GFS, and provide a glimpse into the future for high-latitude GFSs globally where primary production is projected to increase with ongoing glacier shrinkage.
Collapse
Affiliation(s)
- Grégoire Michoud
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Tyler J. Kohler
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Leïla Ezzat
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Hannes Peter
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Juliet Kigongo Nattabi
- Department of Zoology, Entomology and Fisheries Sciences (ZEFs), College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Rosemary Nalwanga
- Department of Zoology, Entomology and Fisheries Sciences (ZEFs), College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Paraskevi Pramateftaki
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Michail Styllas
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Matteo Tolosano
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Vincent De Staercke
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Martina Schön
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ramona Marasco
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Daniele Daffonchio
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Massimo Bourquin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Susheel Bhanu Busi
- Systems Ecology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Tom J. Battin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| |
Collapse
|
8
|
Wang G, Yin X, Feng Z, Chen C, Chen D, Wu B, Liu C, Morel JL, Jiang Y, Yu H, He H, Chao Y, Tang Y, Qiu R, Wang S. Novel biological aqua crust enhances in situ metal(loid) bioremediation driven by phototrophic/diazotrophic biofilm. MICROBIOME 2023; 11:110. [PMID: 37202810 DOI: 10.1186/s40168-023-01549-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 04/13/2023] [Indexed: 05/20/2023]
Abstract
BACKGROUND Understanding the ecological and environmental functions of phototrophic biofilms in the biological crust is crucial for improving metal(loid) (e.g. Cd, As) bioremediation in mining ecosystems. In this study, in combination with metal(loid) monitoring and metagenomic analysis, we systematically evaluated the effect of biofilm in a novel biological aqua crust (biogenic aqua crust-BAC) on in situ metal(loid) bioremediation of a representative Pb/Zn tailing pond. RESULTS We observed strong accumulation of potentially bioavailable metal(loid)s and visible phototrophic biofilms in the BAC. Furthermore, dominating taxa Leptolyngbyaceae (10.2-10.4%, Cyanobacteria) and Cytophagales (12.3-22.1%, Bacteroidota) were enriched in biofilm. Along with predominant heterotrophs (e.g. Cytophagales sp.) as well as diazotrophs (e.g. Hyphomonadaceae sp.), autotrophs/diazotrophs (e.g. Leptolyngbyaceae sp.) in phototrophic biofilm enriched the genes encoding extracellular peptidase (e.g. family S9, S1), CAZymes (e.g. CBM50, GT2) and biofilm formation (e.g. OmpR, CRP and LuxS), thus enhancing the capacity of nutrient accumulation and metal(loid) bioremediation in BAC system. CONCLUSIONS Our study demonstrated that a phototrophic/diazotrophic biofilm constitutes the structured communities containing specific autotrophs (e.g. Leptolyngbyaceae sp.) and heterotrophs (e.g. Cytophagales sp.), which effectively control metal(loid) and nutrient input using solar energy in aquatic environments. Elucidation of the mechanisms of biofilm formation coupled with metal(loid) immobilization in BAC expands the fundamental understanding of the geochemical fate of metal(loid)s, which may be harnessed to enhance in situ metal(loid) bioremediation in the aquatic ecosystem of the mining area. Video Abstract.
Collapse
Affiliation(s)
- Guobao Wang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Xiuran Yin
- Microbial Ecophysiology Group, University of Bremen, Bremen, Germany
| | - Zekai Feng
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Chiyu Chen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Daijie Chen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Bo Wu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Chong Liu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Jean Louis Morel
- Laboratoire Sols Et Environnement, UMR 1120, Université de Lorraine, INRAE, 54518, Vandoeuvre-Lès-Nancy, France
| | - Yuanyuan Jiang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Hang Yu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Huan He
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Yuanqing Chao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Yetao Tang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China.
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
| | - Shizhong Wang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China.
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China.
| |
Collapse
|
9
|
Xia R, Sun M, Balcázar JL, Yu P, Hu F, Alvarez PJJ. Benzo[a]pyrene stress impacts adaptive strategies and ecological functions of earthworm intestinal viromes. THE ISME JOURNAL 2023:10.1038/s41396-023-01408-x. [PMID: 37069233 DOI: 10.1038/s41396-023-01408-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 03/24/2023] [Accepted: 03/30/2023] [Indexed: 04/19/2023]
Abstract
The earthworm gut virome influences the structure and function of the gut microbiome, which in turn influences worm health and ecological functions. However, despite its ecological and soil quality implications, it remains elusive how earthworm intestinal phages respond to different environmental stress, such as soil pollution. Here we used metagenomics and metatranscriptomics to investigate interactions between the worm intestinal phages and their bacteria under different benzo[a]pyrene (BaP) concentrations. Low-level BaP (0.1 mg kg-1) stress stimulated microbial metabolism (1.74-fold to control), and enhanced the antiphage defense system (n = 75) against infection (8 phage-host pairs). Low-level BaP exposure resulted in the highest proportion of lysogenic phages (88%), and prophages expressed auxiliary metabolic genes (AMGs) associated with nutrient transformation (e.g., amino acid metabolism). In contrast, high-level BaP exposure (200 mg kg-1) disrupted microbial metabolism and suppressed the antiphage systems (n = 29), leading to the increase in phage-bacterium association (37 phage-host pairs) and conversion of lysogenic to lytic phages (lysogenic ratio declined to 43%). Despite fluctuating phage-bacterium interactions, phage-encoded AMGs related to microbial antioxidant and pollutant degradation were enriched, apparently to alleviate pollution stress. Overall, these findings expand our knowledge of complex phage-bacterium interactions in pollution-stressed worm guts, and deepen our understanding of the ecological and evolutionary roles of phages.
Collapse
Affiliation(s)
- Rong Xia
- Soil Ecology Lab, Key Laboratory of Plant Immunity, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization and Jiangsu Key Laboratory for Solid Organic Waste Utilization, Nanjing, 210095, China
| | - Mingming Sun
- Soil Ecology Lab, Key Laboratory of Plant Immunity, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization and Jiangsu Key Laboratory for Solid Organic Waste Utilization, Nanjing, 210095, China.
| | - José Luis Balcázar
- Catalan Institute for Water Research (ICRA), 17003, Girona, Spain
- University of Girona, 17004, Girona, Spain
| | - Pingfeng Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310085, China.
| | - Feng Hu
- Soil Ecology Lab, Key Laboratory of Plant Immunity, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization and Jiangsu Key Laboratory for Solid Organic Waste Utilization, Nanjing, 210095, China
| | - Pedro J J Alvarez
- Civil and Environmental Engineering Department, Rice University, Houston, TX, 77005, USA
| |
Collapse
|
10
|
Homogeneous Environmental Selection Structures the Bacterial Communities of Benthic Biofilms in Proglacial Floodplain Streams. Appl Environ Microbiol 2023; 89:e0201022. [PMID: 36847567 PMCID: PMC10053691 DOI: 10.1128/aem.02010-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
In proglacial floodplains, glacier recession promotes biogeochemical and ecological gradients across relatively small spatial scales. The resulting environmental heterogeneity induces remarkable microbial biodiversity among proglacial stream biofilms. Yet the relative importance of environmental constraints in forming biofilm communities remains largely unknown. Extreme environmental conditions in proglacial streams may lead to the homogenizing selection of biofilm-forming microorganisms. However, environmental differences between proglacial streams may impose different selective forces, resulting in nested, spatially structured assembly processes. Here, we investigated bacterial community assembly processes by unraveling ecologically successful phylogenetic clades in two stream types (glacier-fed mainstems and non-glacier-fed tributaries) draining three proglacial floodplains in the Swiss Alps. Clades with low phylogenetic turnover rates were present in all stream types, including Gammaproteobacteria and Alphaproteobacteria, while the other clades were specific to one stream type. These clades constituted up to 34.8% and 31.1% of the community diversity and up to 61.3% and 50.9% of the relative abundances in mainstems and tributaries, respectively, highlighting their importance and success in these communities. Furthermore, the proportion of bacteria under homogeneous selection was inversely related to the abundance of photoautotrophs, and these clades may therefore decrease in abundance with the future "greening" of proglacial habitats. Finally, we found little effect of physical distance from the glacier on clades under selection in glacier-fed streams, probably due to the high hydrological connectivity of our study reaches. Overall, these findings shed new light on the mechanisms of microbial biofilm assembly in proglacial streams and help us to predict their future in a rapidly changing environment. IMPORTANCE Streams draining proglacial floodplains harbor benthic biofilms comprised of diverse microbial communities. These high-mountain ecosystems are rapidly changing with climate warming, and it is therefore critical to better understand the mechanisms underlying the assembly of their microbial communities. We found that homogeneous selection dominates the structuring of bacterial communities in benthic biofilms in both glacier-fed mainstems and nonglacier tributary streams within three proglacial floodplains in the Swiss Alps. However, differences between glacier-fed and tributary ecosystems may impose differential selective forces. Here, we uncovered nested, spatially structured assembly processes for proglacial floodplain communities. Our analyses additionally provided insights into linkages between aquatic photoautotrophs and the bacterial taxa under homogeneous selection, potentially by providing a labile source of carbon in these otherwise carbon-deprived systems. In the future, we expect a shift in the bacterial communities under homogeneous selection in glacier-fed streams as primary production becomes more important and streams become "greener".
Collapse
|
11
|
Busi SB, de Nies L, Pramateftaki P, Bourquin M, Kohler TJ, Ezzat L, Fodelianakis S, Michoud G, Peter H, Styllas M, Tolosano M, De Staercke V, Schön M, Galata V, Wilmes P, Battin T. Glacier-Fed Stream Biofilms Harbor Diverse Resistomes and Biosynthetic Gene Clusters. Microbiol Spectr 2023; 11:e0406922. [PMID: 36688698 PMCID: PMC9927545 DOI: 10.1128/spectrum.04069-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 12/22/2022] [Indexed: 01/24/2023] Open
Abstract
Antimicrobial resistance (AMR) is a universal phenomenon the origins of which lay in natural ecological interactions such as competition within niches, within and between micro- to higher-order organisms. To study these phenomena, it is crucial to examine the origins of AMR in pristine environments, i.e., limited anthropogenic influences. In this context, epilithic biofilms residing in glacier-fed streams (GFSs) are an excellent model system to study diverse, intra- and inter-domain, ecological crosstalk. We assessed the resistomes of epilithic biofilms from GFSs across the Southern Alps (New Zealand) and the Caucasus (Russia) and observed that both bacteria and eukaryotes encoded twenty-nine distinct AMR categories. Of these, beta-lactam, aminoglycoside, and multidrug resistance were both abundant and taxonomically distributed in most of the bacterial and eukaryotic phyla. AMR-encoding phyla included Bacteroidota and Proteobacteria among the bacteria, alongside Ochrophyta (algae) among the eukaryotes. Additionally, biosynthetic gene clusters (BGCs) involved in the production of antibacterial compounds were identified across all phyla in the epilithic biofilms. Furthermore, we found that several bacterial genera (Flavobacterium, Polaromonas, Superphylum Patescibacteria) encode both atimicrobial resistance genes (ARGs) and BGCs within close proximity of each other, demonstrating their capacity to simultaneously influence and compete within the microbial community. Our findings help unravel how naturally occurring BGCs and AMR contribute to the epilithic biofilms mode of life in GFSs. Additionally, we report that eukaryotes may serve as AMR reservoirs owing to their potential for encoding ARGs. Importantly, these observations may be generalizable and potentially extended to other environments that may be more or less impacted by human activity. IMPORTANCE Antimicrobial resistance is an omnipresent phenomenon in the anthropogenically influenced ecosystems. However, its role in shaping microbial community dynamics in pristine environments is relatively unknown. Using metagenomics, we report the presence of antimicrobial resistance genes and their associated pathways in epilithic biofilms within glacier-fed streams. Importantly, we observe biosynthetic gene clusters associated with antimicrobial resistance in both pro- and eukaryotes in these biofilms. Understanding the role of resistance in the context of this pristine environment and complex biodiversity may shed light on previously uncharacterized mechanisms of cross-domain interactions.
Collapse
Affiliation(s)
- Susheel Bhanu Busi
- Systems Ecology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Laura de Nies
- Systems Ecology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Paraskevi Pramateftaki
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Massimo Bourquin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Tyler J. Kohler
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Leïla Ezzat
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Stilianos Fodelianakis
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Grégoire Michoud
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Hannes Peter
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Michail Styllas
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Matteo Tolosano
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Vincent De Staercke
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Martina Schön
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Valentina Galata
- Systems Ecology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Paul Wilmes
- Systems Ecology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Tom Battin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| |
Collapse
|
12
|
Rolli E, Marasco R, Fusi M, Scaglia B, Schubotz F, Mapelli F, Ciccazzo S, Brusetti L, Trombino L, Tambone F, Adani F, Borin S, Daffonchio D. Environmental micro-niche filtering shapes bacterial pioneer communities during primary colonization of a Himalayas' glacier forefield. Environ Microbiol 2022; 24:5998-6016. [PMID: 36325730 PMCID: PMC10099744 DOI: 10.1111/1462-2920.16268] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022]
Abstract
The pedogenesis from the mineral substrate released upon glacier melting has been explained with the succession of consortia of pioneer microorganisms, whose structure and functionality are determined by the environmental conditions developing in the moraine. However, the microbiome variability that can be expected in the environmentally heterogeneous niches occurring in a moraine at a given successional stage is poorly investigated. In a 50 m2 area in the forefield of the Lobuche glacier (Himalayas, 5050 m above sea level), we studied six sites of primary colonization presenting different topographical features (orientation, elevation and slope) and harbouring greyish/dark biological soil crusts (BSCs). The spatial vicinity of the sites opposed to their topographical differences, allowed us to examine the effect of environmental conditions independently from the time of deglaciation. The bacterial microbiome diversity and their co-occurrence network, the bacterial metabolisms predicted from 16S rRNA gene high-throughput sequencing, and the microbiome intact polar lipids were investigated in the BSCs and the underlying sediment deep layers (DLs). Different bacterial microbiomes inhabited the BSCs and the DLs, and their composition varied among sites, indicating a niche-specific role of the micro-environmental conditions in the bacterial communities' assembly. In the heterogeneous sediments of glacier moraines, physico-chemical and micro-climatic variations at the site-spatial scale are crucial in shaping the microbiome microvariability and structuring the pioneer bacterial communities during pedogenesis.
Collapse
Affiliation(s)
- Eleonora Rolli
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy
| | - Ramona Marasco
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Marco Fusi
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Centre for Conservation and Restoration Science, Edinburgh Napier University, Edinburgh, UK
| | - Barbara Scaglia
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy-Gruppo Ricicla Lab, University of Milan, Milan, Italy
| | - Florence Schubotz
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Francesca Mapelli
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy
| | - Sonia Ciccazzo
- Faculty of Science and Technology, Free University of Bolzano, Bolzano, Italy
| | - Lorenzo Brusetti
- Faculty of Science and Technology, Free University of Bolzano, Bolzano, Italy
| | - Luca Trombino
- Department of Earth Sciences 'Ardito Desio', University of Milan, Milan, Italy
| | - Fulvia Tambone
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy-Gruppo Ricicla Lab, University of Milan, Milan, Italy
| | - Fabrizio Adani
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy-Gruppo Ricicla Lab, University of Milan, Milan, Italy
| | - Sara Borin
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy
| | - Daniele Daffonchio
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| |
Collapse
|
13
|
Chen Z, Dolfing J, Zhuang S, Wu Y. Periphytic biofilms-mediated microbial interactions and their impact on the nitrogen cycle in rice paddies. ECO-ENVIRONMENT & HEALTH (ONLINE) 2022; 1:172-180. [PMID: 38075597 PMCID: PMC10702904 DOI: 10.1016/j.eehl.2022.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 09/13/2022] [Accepted: 09/29/2022] [Indexed: 01/03/2024]
Abstract
Rice paddies are unique waterlogged wetlands artificially constructed for agricultural production. Periphytic biofilms (PBs) at the soil-water interface play an important role in rice paddies characterized by high nutrient input but low utilization efficiency. PBs are composed of microbial aggregates, including a wide variety of microorganisms (algae, bacteria, fungi, protozoa, and metazoa), extracellular polymeric substances and minerals (iron, aluminum, and calcium), which form an integrated food web and energy flux within a relatively stable micro-ecosystem. PBs are crucial to regulate and streamline the nitrogen cycle by neutralizing nitrogen losses and improving rice production since PBs can serve as both a sink by capturing surplus nitrogen and a source by slowly re-releasing this nitrogen for reutilization. Here the ecological advantages of PBs in regulating the nitrogen cycle in rice paddies are illustrated. We summarize the key functional importance of PBs, including the intricate and delicate community structure, microbial interactions among individual phylotypes, a wide diversity of self-produced organics, the active adaptation of PBs to constantly changing environments, and the intricate mechanisms by which PBs regulate the nitrogen cycle. We also identify the future challenges of microbial interspecific cooperation in PBs and their quantitative contributions to agricultural sustainability, optimizing nitrogen utilization and crop yields in rice paddies.
Collapse
Affiliation(s)
- Zhihao Chen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- Zigui Three Gorges Reservoir Ecosystem, Observation and Research Station of Ministry of Water Resources of the People's Republic of China, Yichang 443605, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jan Dolfing
- Faculty of Energy and Environment, Northumbria University, Newcastle Upon Tyne NE1 8QH, UK
| | - Shunyao Zhuang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yonghong Wu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- Zigui Three Gorges Reservoir Ecosystem, Observation and Research Station of Ministry of Water Resources of the People's Republic of China, Yichang 443605, China
| |
Collapse
|
14
|
Brandani J, Peter H, Busi SB, Kohler TJ, Fodelianakis S, Ezzat L, Michoud G, Bourquin M, Pramateftaki P, Roncoroni M, Lane SN, Battin TJ. Spatial patterns of benthic biofilm diversity among streams draining proglacial floodplains. Front Microbiol 2022; 13:948165. [PMID: 36003939 PMCID: PMC9393633 DOI: 10.3389/fmicb.2022.948165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/11/2022] [Indexed: 11/20/2022] Open
Abstract
Glacier shrinkage opens new proglacial terrain with pronounced environmental gradients along longitudinal and lateral chronosequences. Despite the environmental harshness of the streams that drain glacier forelands, their benthic biofilms can harbor astonishing biodiversity spanning all domains of life. Here, we studied the spatial dynamics of prokaryotic and eukaryotic photoautotroph diversity within braided glacier-fed streams and tributaries draining lateral terraces predominantly fed by groundwater and snowmelt across three proglacial floodplains in the Swiss Alps. Along the lateral chronosequence, we found that benthic biofilms in tributaries develop higher biomass than those in glacier-fed streams, and that their respective diversity and community composition differed markedly. We also found spatial turnover of bacterial communities in the glacier-fed streams along the longitudinal chronosequence. These patterns along the two chronosequences seem unexpected given the close spatial proximity and connectivity of the various streams, suggesting environmental filtering as an underlying mechanism. Furthermore, our results suggest that photoautotrophic communities shape bacterial communities across the various streams, which is understandable given that algae are the major source of organic matter in proglacial streams. Overall, our findings shed new light on benthic biofilms in proglacial streams now changing at rapid pace owing to climate-induced glacier shrinkage.
Collapse
Affiliation(s)
- Jade Brandani
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Hannes Peter
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Susheel Bhanu Busi
- Systems Ecology Group, Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Tyler J. Kohler
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Stilianos Fodelianakis
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Leila Ezzat
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Grégoire Michoud
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Massimo Bourquin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Paraskevi Pramateftaki
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Matteo Roncoroni
- Institute of Earth Surface Dynamics (IDYST), University of Lausanne, Lausanne, Switzerland
| | - Stuart N. Lane
- Institute of Earth Surface Dynamics (IDYST), University of Lausanne, Lausanne, Switzerland
| | - Tom J. Battin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- *Correspondence: Tom J. Battin,
| |
Collapse
|