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Thøgersen MS, Zervas A, Stougaard P, Ellegaard-Jensen L. Investigating eukaryotic and prokaryotic diversity and functional potential in the cold and alkaline ikaite columns in Greenland. Front Microbiol 2024; 15:1358787. [PMID: 38655082 PMCID: PMC11035741 DOI: 10.3389/fmicb.2024.1358787] [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: 12/20/2023] [Accepted: 03/08/2024] [Indexed: 04/26/2024] Open
Abstract
The ikaite columns in the Ikka Fjord, SW Greenland, represent a permanently cold and alkaline environment known to contain a rich bacterial diversity. 16S and 18S rRNA gene amplicon and metagenomic sequencing was used to investigate the microbial diversity in the columns and for the first time, the eukaryotic and archaeal diversity in ikaite columns were analyzed. The results showed a rich prokaryotic diversity that varied across columns as well as within each column. Seven different archaeal phyla were documented in multiple locations inside the columns. The columns also contained a rich eukaryotic diversity with 27 phyla representing microalgae, protists, fungi, and small animals. Based on metagenomic sequencing, 25 high-quality MAGs were assembled and analyzed for the presence of genes involved in cycling of nitrogen, sulfur, and phosphorous as well as genes encoding carbohydrate-active enzymes (CAZymes), showing a potentially very bioactive microbial community.
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Benning LG, Wagner D, Larose C, Gunde-Cimerman N, Häggblom MM. Editorial: thematic issue on Polar and Alpine Microbiology. FEMS Microbiol Ecol 2024; 100:fiae030. [PMID: 38518222 PMCID: PMC10959548 DOI: 10.1093/femsec/fiae030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 03/08/2024] [Indexed: 03/24/2024] Open
Affiliation(s)
- Liane G Benning
- German Research Centre for Geosciences GFZ, Telegrafenberg A71-359, 14473 Potsdam, Germany
| | - Dirk Wagner
- German Research Centre for Geosciences GFZ, Telegrafenberg A71-359, 14473 Potsdam, Germany
| | - Catherine Larose
- Université Grenoble Alpes, CNRS, Institute of Geosciences of the Environment IGE, CS 40700, 38 058 Grenoble, France
| | - Nina Gunde-Cimerman
- University of Ljubljana, Department of Biology, Biotechnical faculty, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Max M Häggblom
- Rutgers University, Department of Biochemistry and Microbiology, 76 Lipman Drive, New Brunswick, NJ 08901-8525, United States
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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.
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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
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Jaarsma AH, Zervas A, Sipes K, Campuzano Jiménez F, Smith AC, Svendsen LV, Thøgersen MS, Stougaard P, Benning LG, Tranter M, Anesio AM. The undiscovered biosynthetic potential of the Greenland Ice Sheet microbiome. Front Microbiol 2023; 14:1285791. [PMID: 38149278 PMCID: PMC10749974 DOI: 10.3389/fmicb.2023.1285791] [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: 08/30/2023] [Accepted: 11/24/2023] [Indexed: 12/28/2023] Open
Abstract
The Greenland Ice Sheet is a biome which is mainly microbially driven. Several different niches can be found within the glacial biome for those microbes able to withstand the harsh conditions, e.g., low temperatures, low nutrient conditions, high UV radiation in summer, and contrasting long and dark winters. Eukaryotic algae can form blooms during the summer on the ice surface, interacting with communities of bacteria, fungi, and viruses. Cryoconite holes and snow are also habitats with their own microbial community. Nevertheless, the microbiome of supraglacial habitats remains poorly studied, leading to a lack of representative genomes from these environments. Under-investigated extremophiles, like those living on the Greenland Ice Sheet, may provide an untapped reservoir of chemical diversity that is yet to be discovered. In this study, an inventory of the biosynthetic potential of these organisms is made, through cataloging the presence of biosynthetic gene clusters in their genomes. There were 133 high-quality metagenome-assembled genomes (MAGs) and 28 whole genomes of bacteria obtained from samples of the ice sheet surface, cryoconite, biofilm, and snow using culturing-dependent and -independent approaches. AntiSMASH and BiG-SCAPE were used to mine these genomes and subsequently analyze the resulting predicted gene clusters. Extensive sets of predicted Biosynthetic Gene Clusters (BGCs) were collected from the genome collection, with limited overlap between isolates and MAGs. Additionally, little overlap was found in the biosynthetic potential among different environments, suggesting specialization of organisms in specific habitats. The median number of BGCs per genome was significantly higher for the isolates compared to the MAGs. The most talented producers were found among Proteobacteria. We found evidence for the capacity of these microbes to produce antimicrobials, carotenoid pigments, siderophores, and osmoprotectants, indicating potential survival mechanisms to cope with extreme conditions. The majority of identified BGCs, including those in the most prevalent gene cluster families, have unknown functions, presenting a substantial potential for bioprospecting. This study underscores the diverse biosynthetic potential in Greenland Ice Sheet genomes, revealing insights into survival strategies and highlighting the need for further exploration and characterization of these untapped resources.
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Affiliation(s)
- Ate H. Jaarsma
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Athanasios Zervas
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Katie Sipes
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | | | | | | | | | - Peter Stougaard
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Liane G. Benning
- German Research Centre for Geosciences, Helmholtz Centre Potsdam, Potsdam, Germany
- Department of Earth Sciences, Freie Universität Berlin, Berlin, Germany
| | - Martyn Tranter
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
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