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Antony R, Mongad D, Sanyal A, Dhotre D, Thamban M. Holed up, but thriving: Impact of multitrophic cryoconite communities on glacier elemental cycles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 933:173187. [PMID: 38750762 DOI: 10.1016/j.scitotenv.2024.173187] [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: 12/11/2023] [Revised: 05/10/2024] [Accepted: 05/10/2024] [Indexed: 05/20/2024]
Abstract
Cryoconite holes (water and sediment-filled depressions), found on glacier surfaces worldwide, serve as reservoirs of microbes, carbon, trace elements, and nutrients, transferring these components downstream via glacier hydrological networks. Through targeted amplicon sequencing of carbon and nitrogen cycling genes, coupled with functional inference-based methods, we explore the functional diversity of these mini-ecosystems within Antarctica and the Himalayas. These regions showcase distinct environmental gradients and experience varying rates of environmental change influenced by global climatic shifts. Analysis revealed a diverse array of photosynthetic microorganisms, including Stramenopiles, Cyanobacteria, Rhizobiales, Burkholderiales, and photosynthetic purple sulfur Proteobacteria. Functional inference highlighted the high potential for carbohydrate, amino acid, and lipid metabolism in the Himalayan region, where organic carbon concentrations surpassed those in Antarctica by up to 2 orders of magnitude. Nitrogen cycling processes, including fixation, nitrification, and denitrification, are evident, with Antarctic cryoconite exhibiting a pronounced capacity for nitrogen fixation, potentially compensating for the limited nitrate concentrations in this region. Processes associated with the respiration of elemental sulfur and inorganic sulfur compounds such as sulfate, sulfite, thiosulfate, and sulfide suggest the presence of a complete sulfur cycle. The Himalayan region exhibits a higher potential for sulfur cycling, likely due to the abundant sulfate ions and sulfur-bearing minerals in this region. The capability for complete iron cycling through iron oxidation and reduction reactions was also predicted. Methanogenic archaea that produce methane during organic matter decomposition and methanotrophic bacteria that utilize methane as carbon and energy sources co-exist in the cryoconite, suggesting that these niches support the complete cycling of methane. Additionally, the presence of various microfauna suggests the existence of a complex food web. Collectively, these results indicate that cryoconite holes are self-sustaining ecosystems that drive elemental cycles on glaciers and potentially control carbon, nitrogen, sulfur, and iron exports downstream.
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Affiliation(s)
- Runa Antony
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco-da-Gama, India; GFZ German Research Centre for Geosciences, Potsdam, Germany.
| | - Dattatray Mongad
- National Centre for Microbial Resource, National Centre for Cell Science, Pune, India
| | - Aritri Sanyal
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco-da-Gama, India
| | - Dhiraj Dhotre
- National Centre for Microbial Resource, National Centre for Cell Science, Pune, India
| | - Meloth Thamban
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco-da-Gama, India
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Jia P, Tian M, Zhang B, Wu X, He X, Zhang W. Habitat changes due to glacial freezing and melting reshape microbial networks. ENVIRONMENT INTERNATIONAL 2024; 189:108788. [PMID: 38838490 DOI: 10.1016/j.envint.2024.108788] [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: 03/03/2024] [Revised: 05/15/2024] [Accepted: 05/29/2024] [Indexed: 06/07/2024]
Abstract
The phenomenon of glacial freezing and thawing involves microbial sequestration, release, and colonization, which has the potential to impact ecosystem functioning through changes in microbial diversity and interactions. In this study, we examined the structural features of microbial communities of the Dongkemadi glacier, including bacteria, fungi, and archaea, in four distinct glacial environments (snow, ice, meltwater, and frontier soil). The sequestration, release, and colonization of glacial microbes have been found to significantly impact the diversity and structure of glacial microbial communities, as well as the complexity of microbial networks. Specifically, the complexity of bacterial networks has been observed to increase in a sequential manner during these processes. Utilizing the Inter-Domain Ecological Network approach, researchers have further explored the cross-trophic interactions among bacteria, fungi, and archaea. The complexity of the bacteria-fungi-archaea network exhibited a sequential increase due to the processes of sequestration, release, and colonization of glacial microbes. The release and colonization of glacial microbes led to a shift in the role of archaea as key species within the network. Additionally, our findings suggest that the hierarchical interactions among various microorganisms contributed to the heightened complexity of the bacteria-fungi-archaea network. The primary constituents of the glacial microbial ecosystem are unclassified species associated with the Polaromonas. It is noteworthy that various key species in glacial ecosystems are influenced by the distinct environmental factors. Moreover, our findings suggest that key species are not significantly depleted in response to abrupt alterations in individual environmental factors, shedding light on the dynamics of microbial cross-trophic interactions within glacial ecosystems.
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Affiliation(s)
- Puchao Jia
- Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Extreme Environmental Microbial Resources and Engineering of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mao Tian
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Binglin Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xiukun Wu
- Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Extreme Environmental Microbial Resources and Engineering of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xiaobo He
- Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Tanggula Mountain Cryosphere and Environment Observation and Research Station of Tibet Autonomous Region, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Wei Zhang
- Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Extreme Environmental Microbial Resources and Engineering of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
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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.
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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.
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Zhang C, Ren Z. The role of subsurface ice in sustaining bacteria in continental and maritime glaciers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 896:165324. [PMID: 37414181 DOI: 10.1016/j.scitotenv.2023.165324] [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: 04/07/2023] [Revised: 06/29/2023] [Accepted: 07/02/2023] [Indexed: 07/08/2023]
Abstract
In supraglacial environments, surface and subsurface ices are two distinct and connected microhabitats in terms of physicochemical and biological aspects. At the frontline of climate change, glaciers lose tremendous ice masses to downstream ecosystems, serving as crucial sources of both biotic and abiotic materials. In this study, we studied the disparities and relationships of microbial communities between surface and subsurface ices collected from a maritime and a continental glacier during summer. The results showed that surface ices had significantly higher nutrients and were more physiochemically different than subsurface ices. Despite lower nutrients, subsurface ices had higher alpha-diversity with more unique and enriched operational taxonomic units (OTUs) than surface ices, indicating the potential role of subsurface as a bacterial refuge. Sorensen dissimilarity between bacterial communities in surface ices and subsurface ices was mainly contributed by the turnover component, suggesting strong species replacement from surface to subsurface ices due to large environmental gradients. For different glaciers, the maritime glacier had significantly higher alpha-diversity than the continental glacier. The difference between surface and subsurface communities was more pronounced in the maritime glacier than in the continental glacier. The network analysis revealed that surface-enriched and subsurface-enriched OTUs formed independent modules, with surface-enriched OTUs having closer interconnections and greater importance in the network of the maritime glacier. This study highlights the important role of subsurface ice as a bacterial refuge and enriches our knowledge of microbial properties in glaciers.
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Affiliation(s)
- Cheng Zhang
- School of Engineering Technology, Beijing Normal University, Zhuhai, China; Instrumentation and Service Center for Science and Technology, Beijing Normal University, Zhuhai, China
| | - Ze Ren
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
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Ren Z, Cao S, Chen T, Zhang C, Yu J. Bacterial functional redundancy and carbon metabolism potentials in soil, sediment, and water of thermokarst landscapes across the Qinghai-Tibet Plateau: Implications for the fate of permafrost carbon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158340. [PMID: 36041614 DOI: 10.1016/j.scitotenv.2022.158340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Permafrost thaw create widespread thermokarst landscapes. As a result, distinct habitats are provided to harbor different bacterial communities in degraded permafrost soil (PBCs), thermokarst lake sediment (SBCs), and lake water (WBCs), driving carbon metabolism differentially. In this study, we investigated functional diversity and redundancy, and carbon metabolism potentials of PBCs, SBCs, and WBCs in thermokarst landscapes across the Qinghai-Tibet Plateau. The results showed that PBCs and SBCs had higher taxonomic and functional alpha diversity than WBCs, while WBCs had lower functional redundancy. WBCs had the highest beta diversity followed by SBCs and PBCs, suggesting strong determination of taxonomic variations on functional differences. Community assembly processes also had significant influences on beta diversity, especially for SBCs. Metabolism pathways of carbohydrate metabolism, methane metabolism, and carbon fixation were enriched differentially in PBCs, SBCs, and WBCs, suggesting different C fate in distinct habitats. Carbohydrate metabolism data suggested that PBCs might have stronger potentials to mineralize a greater diversity of organic carbon substrate than SBCs and WBCs, promoting degradation of organic carbon stocks in degraded permafrost soils. Methane metabolism data showed that SBCs had a stronger methanogenesis potential followed by PBCs and WBCs, while PBCs had a stronger methane oxidation potential. High abundance of genes involving in formaldehyde assimilation might suggested that a large proportion of produced methane might be assimilated by methanotrophs in the thermokarst landscapes. Both aerobic and anaerobic carbon fixation pathways were enriched in PBCs. The results added our understanding of functional properties and biogeochemical carbon cycles in thermokarst landscapes, improving our abilities in accurate modeling of carbon dynamics and the ultimate fate of permafrost carbon in a warming world.
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Affiliation(s)
- Ze Ren
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China; School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Shengkui Cao
- School of Geographical Science, Qinghai Normal University, Xining 810008, China.
| | - Tao Chen
- Center for Grassland Microbiome, State Key Laboratory of Grassland Agro-ecosystems, Lanzhou University, Lanzhou 730020, China
| | - Cheng Zhang
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China; School of Engineering Technology, Beijing Normal University, Zhuhai 519087, China
| | - Jinlei Yu
- Key Laboratory of Geographic Information Science, Ministry of Education, East China Normal University, Shanghai 200241, China
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