1
|
Li Y, Yu T, Feng X, Zhao B, Chen H, Yang H, Chen X, Zhang XH, Anderson HR, Burns NZ, Zeng F, Tao L, Zeng Z. Biosynthesis of GMGT lipids by a radical SAM enzyme associated with anaerobic archaea and oxygen-deficient environments. Nat Commun 2024; 15:5256. [PMID: 38898040 PMCID: PMC11186832 DOI: 10.1038/s41467-024-49650-x] [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: 01/18/2024] [Accepted: 06/11/2024] [Indexed: 06/21/2024] Open
Abstract
Archaea possess characteristic membrane-spanning lipids that are thought to contribute to the adaptation to extreme environments. However, the biosynthesis of these lipids is poorly understood. Here, we identify a radical S-adenosyl-L-methionine (SAM) enzyme that synthesizes glycerol monoalkyl glycerol tetraethers (GMGTs). The enzyme, which we name GMGT synthase (Gms), catalyzes the formation of a C(sp3)-C(sp3) linkage between the two isoprenoid chains of glycerol dialkyl glycerol tetraethers (GDGTs). This conclusion is supported by heterologous expression of gene gms from a GMGT-producing species in a methanogen, as well as demonstration of in vitro activity using purified Gms enzyme. Additionally, we show that genes encoding putative Gms homologs are present in obligate anaerobic archaea and in metagenomes obtained from oxygen-deficient environments, and appear to be absent in metagenomes from oxic settings.
Collapse
Affiliation(s)
- Yanan Li
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, China
| | - Ting Yu
- Department of Systems Biology and Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, China
| | - Xi Feng
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Bo Zhao
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Huahui Chen
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Huan Yang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Xing Chen
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiao-Hua Zhang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | | | - Noah Z Burns
- Department of Chemistry, Stanford University, Stanford, USA
| | - Fuxing Zeng
- Department of Systems Biology and Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, China.
| | - Lizhi Tao
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, China.
| | - Zhirui Zeng
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China.
| |
Collapse
|
2
|
Cifuente JO, Colleoni C, Kalscheuer R, Guerin ME. Architecture, Function, Regulation, and Evolution of α-Glucans Metabolic Enzymes in Prokaryotes. Chem Rev 2024; 124:4863-4934. [PMID: 38606812 PMCID: PMC11046441 DOI: 10.1021/acs.chemrev.3c00811] [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] [Indexed: 04/13/2024]
Abstract
Bacteria have acquired sophisticated mechanisms for assembling and disassembling polysaccharides of different chemistry. α-d-Glucose homopolysaccharides, so-called α-glucans, are the most widespread polymers in nature being key components of microorganisms. Glycogen functions as an intracellular energy storage while some bacteria also produce extracellular assorted α-glucans. The classical bacterial glycogen metabolic pathway comprises the action of ADP-glucose pyrophosphorylase and glycogen synthase, whereas extracellular α-glucans are mostly related to peripheral enzymes dependent on sucrose. An alternative pathway of glycogen biosynthesis, operating via a maltose 1-phosphate polymerizing enzyme, displays an essential wiring with the trehalose metabolism to interconvert disaccharides into polysaccharides. Furthermore, some bacteria show a connection of intracellular glycogen metabolism with the genesis of extracellular capsular α-glucans, revealing a relationship between the storage and structural function of these compounds. Altogether, the current picture shows that bacteria have evolved an intricate α-glucan metabolism that ultimately relies on the evolution of a specific enzymatic machinery. The structural landscape of these enzymes exposes a limited number of core catalytic folds handling many different chemical reactions. In this Review, we present a rationale to explain how the chemical diversity of α-glucans emerged from these systems, highlighting the underlying structural evolution of the enzymes driving α-glucan bacterial metabolism.
Collapse
Affiliation(s)
- Javier O. Cifuente
- Instituto
Biofisika (UPV/EHU, CSIC), University of
the Basque Country, E-48940 Leioa, Spain
| | - Christophe Colleoni
- University
of Lille, CNRS, UMR8576-UGSF -Unité de Glycobiologie Structurale
et Fonctionnelle, F-59000 Lille, France
| | - Rainer Kalscheuer
- Institute
of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, 40225 Dusseldorf, Germany
| | - Marcelo E. Guerin
- Structural
Glycobiology Laboratory, Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona (IBMB), Spanish
National Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac 4-8, Tower R, 08028 Barcelona, Catalonia, Spain
| |
Collapse
|
3
|
Zhang IH, Borer B, Zhao R, Wilbert S, Newman DK, Babbin AR. Uncultivated DPANN archaea are ubiquitous inhabitants of global oxygen-deficient zones with diverse metabolic potential. mBio 2024; 15:e0291823. [PMID: 38380943 PMCID: PMC10936187 DOI: 10.1128/mbio.02918-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
Archaea belonging to the DPANN (Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota) superphylum have been found in an expanding number of environments and perform a variety of biogeochemical roles, including contributing to carbon, sulfur, and nitrogen cycling. Generally characterized by ultrasmall cell sizes and reduced genomes, DPANN archaea may form mutualistic, commensal, or parasitic interactions with various archaeal and bacterial hosts, influencing the ecology and functioning of microbial communities. While DPANN archaea reportedly comprise a sizeable fraction of the archaeal community within marine oxygen-deficient zone (ODZ) water columns, little is known about their metabolic capabilities in these ecosystems. We report 33 novel metagenome-assembled genomes (MAGs) belonging to the DPANN phyla Nanoarchaeota, Pacearchaeota, Woesearchaeota, Undinarchaeota, Iainarchaeota, and SpSt-1190 from pelagic ODZs in the Eastern Tropical North Pacific and the Arabian Sea. We find these archaea to be permanent, stable residents of all three major ODZs only within anoxic depths, comprising up to 1% of the total microbial community and up to 25%-50% of archaea as estimated from read mapping to MAGs. ODZ DPANN appear to be capable of diverse metabolic functions, including fermentation, organic carbon scavenging, and the cycling of sulfur, hydrogen, and methane. Within a majority of ODZ DPANN, we identify a gene homologous to nitrous oxide reductase. Modeling analyses indicate the feasibility of a nitrous oxide reduction metabolism for host-attached symbionts, and the small genome sizes and reduced metabolic capabilities of most DPANN MAGs suggest host-associated lifestyles within ODZs. IMPORTANCE Archaea from the DPANN (Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota) superphylum have diverse metabolic capabilities and participate in multiple biogeochemical cycles. While metagenomics and enrichments have revealed that many DPANN are characterized by ultrasmall genomes, few biosynthetic genes, and episymbiotic lifestyles, much remains unknown about their biology. We report 33 new DPANN metagenome-assembled genomes originating from the three global marine oxygen-deficient zones (ODZs), the first from these regions. We survey DPANN abundance and distribution within the ODZ water column, investigate their biosynthetic capabilities, and report potential roles in the cycling of organic carbon, methane, and nitrogen. We test the hypothesis that nitrous oxide reductases found within several ODZ DPANN genomes may enable ultrasmall episymbionts to serve as nitrous oxide consumers when attached to a host nitrous oxide producer. Our results indicate DPANN archaea as ubiquitous residents within the anoxic core of ODZs with the potential to produce or consume key compounds.
Collapse
Affiliation(s)
- Irene H. Zhang
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Benedict Borer
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Steven Wilbert
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Dianne K. Newman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | - Andrew R. Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| |
Collapse
|
4
|
Sun J, Zhou H, Cheng H, Chen Z, Yang J, Wang Y, Jing C. Depth-Dependent Distribution of Prokaryotes in Sediments of the Manganese Crust on Nazimov Guyots of the Magellan Seamounts. MICROBIAL ECOLOGY 2023; 86:3027-3042. [PMID: 37792089 DOI: 10.1007/s00248-023-02305-8] [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: 05/17/2023] [Accepted: 09/04/2023] [Indexed: 10/05/2023]
Abstract
Deep ocean polymetallic nodules, rich in cobalt, nickel, and titanium which are commonly used in high-technology and biotechnology applications, are being eyed for green energy transition through deep-sea mining operations. Prokaryotic communities underneath polymetallic nodules could participate in deep-sea biogeochemical cycling, however, are not fully described. To address this gap, we collected sediment cores from Nazimov guyots, where polymetallic nodules exist, to explore the diversity and vertical distribution of prokaryotic communities. Our 16S rRNA amplicon sequencing data, quantitative PCR results, and phylogenetic beta diversity indices showed that prokaryotic diversity in the surficial layers (0-8 cm) was > 4-fold higher compared to deeper horizons (8-26 cm), while heterotrophs dominated in all sediment horizons. Proteobacteria was the most abundant taxon (32-82%) across all sediment depths, followed by Thaumarchaeota (4-37%), Firmicutes (2-18%), and Planctomycetes (1-6%). Depth was the key factor controlling prokaryotic distribution, while heavy metals (e.g., iron, copper, nickel, cobalt, zinc) can also influence significantly the downcore distribution of prokaryotic communities. Analyses of phylogenetic diversity showed that deterministic processes governing prokaryotic assembly in surficial layers, contrasting with stochastic influences in deep layers. This was further supported from the detection of a more complex prokaryotic co-occurrence network in the surficial layer which suggested more diverse prokaryotic communities existed in the surface vs. deeper sediments. This study expands current knowledge on the vertical distribution of benthic prokaryotic diversity in deep sea settings underneath polymetallic nodules, and the results reported might set a baseline for future mining decisions.
Collapse
Affiliation(s)
- Jianxing Sun
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
| | - Hongbo Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China
| | - Haina Cheng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China
| | - Zhu Chen
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China
| | - Jichao Yang
- College of Marine Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, People's Republic of China
| | - Yuguang Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China.
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China.
| | - Chunlei Jing
- National Deepsea Center, Ministry of Natural Resources, Qingdao, 266237, Shandong, People's Republic of China.
| |
Collapse
|
5
|
Girard C, Vincent WF, Culley AI. Arctic bacterial diversity and connectivity in the coastal margin of the Last Ice Area. ISME COMMUNICATIONS 2023; 3:105. [PMID: 37752298 PMCID: PMC10522646 DOI: 10.1038/s43705-023-00313-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 09/28/2023]
Abstract
Arctic climate change is leading to sea-ice attrition in the Last Ice Area along the northern coast of Canada and Greenland, but less attention has been given to the associated land-based ecosystems. Here we evaluated bacterial community structure in a hydrologically coupled cryo-ecosystem in the region: Thores Glacier, proglacial Thores Lake, and its outlet to the sea. Deep amplicon sequencing revealed that Polaromonas was ubiquitous, but differed genetically among diverse niches. Surface glacier-ice was dominated by Cyanobacteria, while the perennially ice-capped, well-mixed water column of Thores Lake had a unique assemblage of Chloroflexi, Actinobacteriota, and Planctomycetota. Species richness increased downstream, but glacier microbes were little detected in the lake, suggesting strong taxonomic sorting. Ongoing climate change and the retreat of Thores Glacier would lead to complete drainage and loss of the lake microbial ecosystem, indicating the extreme vulnerability of diverse cryohabitats and unique microbiomes in the Last Ice coastal margin.
Collapse
Affiliation(s)
- Catherine Girard
- Département de biochimie, de microbiologie et de bio-informatique & Institut de biologie intégrative et des systèmes (IBIS), Université Laval, Québec, QC, Canada.
- Centre d'études nordiques (CEN), Québec, QC, Canada.
- Groupe de recherche interuniversitaire en limnologie et en écologie aquatique (GRIL), Montréal, QC, Canada.
- Département des sciences fondamentales, Université du Québec à Chicoutimi (UQAC), Chicoutimi, QC, Canada.
| | - Warwick F Vincent
- Centre d'études nordiques (CEN), Québec, QC, Canada
- Département de biologie & Institut de biologie intégrative et des systèmes (IBIS), Université Laval, Québec, QC, Canada
- Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada
| | - Alexander I Culley
- Département de biochimie, de microbiologie et de bio-informatique & Institut de biologie intégrative et des systèmes (IBIS), Université Laval, Québec, QC, Canada
- Centre d'études nordiques (CEN), Québec, QC, Canada
- Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, HI, USA
| |
Collapse
|
6
|
Vigneron A, Vincent WF, Lovejoy C. Discovery of a novel bacterial class with the capacity to drive sulfur cycling and microbiome structure in a paleo-ocean analog. ISME COMMUNICATIONS 2023; 3:82. [PMID: 37596370 PMCID: PMC10439189 DOI: 10.1038/s43705-023-00287-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/20/2023]
Abstract
Uncultivated microbial taxa represent a large fraction of global microbial diversity and likely drive numerous biogeochemical transformations in natural ecosystems. Geographically isolated, polar ecosystems are complex microbial biomes and refuges of underexplored taxonomic and functional biodiversity. Combining amplicon sequencing with genome-centric metagenomic analysis of samples from one of the world's northernmost lakes (Lake A, Ellesmere Island, Canadian High Arctic), we identified a novel bacterial taxon that dominates in the bottom layer of anoxic, sulfidic, relict sea water that was isolated from the Arctic Ocean some 3000 years ago. Based on phylogenomic comparative analyses, we propose that these bacteria represent a new Class within the poorly described Electryoneota/AABM5-125-24 candidate phylum. This novel class, for which we propose the name Tariuqbacteria, may be either a relict of ancient ocean conditions or endemic to this High Arctic system, provisionally providing a rare example of high-taxonomy level endemism. Consistent with the geochemistry of the bottom water, the genetic composition of the Candidatus Tariuqbacter genome revealed a strictly anaerobic lifestyle with the potential for sulfate and sulfur reduction, a versatile carbon metabolism and the capability to eliminate competing bacteria through methylarsenite production, suggesting an allelochemical influence on microbiome structure by this planktonic microbe.
Collapse
Affiliation(s)
- Adrien Vigneron
- Département de Biologie, Université Laval, Québec, QC, Canada.
- Centre d'études nordiques (CEN), Université Laval, Québec, QC, Canada.
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada.
- Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.
| | - Warwick F Vincent
- Département de Biologie, Université Laval, Québec, QC, Canada
- Centre d'études nordiques (CEN), Université Laval, Québec, QC, Canada
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada
| | - Connie Lovejoy
- Département de Biologie, Université Laval, Québec, QC, Canada
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada
- Québec Océan, Université Laval, Québec, QC, Canada
| |
Collapse
|
7
|
Feehan B, Ran Q, Dorman V, Rumback K, Pogranichniy S, Ward K, Goodband R, Niederwerder MC, Lee STM. Novel complete methanogenic pathways in longitudinal genomic study of monogastric age-associated archaea. Anim Microbiome 2023; 5:35. [PMID: 37461084 DOI: 10.1186/s42523-023-00256-6] [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: 01/16/2023] [Accepted: 07/11/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Archaea perform critical roles in the microbiome system, including utilizing hydrogen to allow for enhanced microbiome member growth and influencing overall host health. With the majority of microbiome research focusing on bacteria, the functions of archaea are largely still under investigation. Understanding methanogenic functions during the host lifetime will add to the limited knowledge on archaeal influence on gut and host health. In our study, we determined lifelong archaea dynamics, including detection and methanogenic functions, while assessing global, temporal and host distribution of our novel archaeal metagenome-assembled genomes (MAGs). We followed 7 monogastric swine throughout their life, from birth to adult (1-156 days of age), and collected feces at 22 time points. The samples underwent gDNA extraction, Illumina sequencing, bioinformatic quality and assembly processes, MAG taxonomic assignment and functional annotation. MAGs were utilized in downstream phylogenetic analysis for global, temporal and host distribution in addition to methanogenic functional potential determination. RESULTS We generated 1130 non-redundant MAGs, representing 588 unique taxa at the species level, with 8 classified as methanogenic archaea. The taxonomic classifications were as follows: orders Methanomassiliicoccales (5) and Methanobacteriales (3); genera UBA71 (3), Methanomethylophilus (1), MX-02 (1), and Methanobrevibacter (3). We recovered the first US swine Methanobrevibacter UBA71 sp006954425 and Methanobrevibacter gottschalkii MAGs. The Methanobacteriales MAGs were identified primarily during the young, preweaned host whereas Methanomassiliicoccales primarily in the adult host. Moreover, we identified our methanogens in metagenomic sequences from Chinese swine, US adult humans, Mexican adult humans, Swedish adult humans, and paleontological humans, indicating that methanogens span different hosts, geography and time. We determined complete metabolic pathways for all three methanogenic pathways: hydrogenotrophic, methylotrophic, and acetoclastic. This study provided the first evidence of acetoclastic methanogenesis in archaea of monogastric hosts which indicated a previously unknown capability for acetate utilization in methanogenesis for monogastric methanogens. Overall, we hypothesized that the age-associated detection patterns were due to differential substrate availability via the host diet and microbial metabolism, and that these methanogenic functions are likely crucial to methanogens across hosts. This study provided a comprehensive, genome-centric investigation of monogastric-associated methanogens which will further improve our understanding of microbiome development and functions.
Collapse
Affiliation(s)
- Brandi Feehan
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Qinghong Ran
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Victoria Dorman
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Kourtney Rumback
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Sophia Pogranichniy
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Kaitlyn Ward
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Robert Goodband
- Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS, 66506, USA
| | | | - Sonny T M Lee
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA.
| |
Collapse
|
8
|
Vigneron A, Cruaud P, Lovejoy C, Vincent WF. Genomic insights into cryptic cycles of microbial hydrocarbon production and degradation in contiguous freshwater and marine microbiomes. MICROBIOME 2023; 11:104. [PMID: 37173775 PMCID: PMC10176705 DOI: 10.1186/s40168-023-01537-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/29/2023] [Indexed: 05/15/2023]
Abstract
BACKGROUND Cyanobacteria and eukaryotic phytoplankton produce long-chain alkanes and generate around 100 times greater quantities of hydrocarbons in the ocean compared to natural seeps and anthropogenic sources. Yet, these compounds do not accumulate in the water column, suggesting rapid biodegradation by co-localized microbial populations. Despite their ecological importance, the identities of microbes involved in this cryptic hydrocarbon cycle are mostly unknown. Here, we identified genes encoding enzymes involved in the hydrocarbon cycle across the salinity gradient of a remote, vertically stratified, seawater-containing High Arctic lake that is isolated from anthropogenic petroleum sources and natural seeps. Metagenomic analysis revealed diverse hydrocarbon cycling genes and populations, with patterns of variation along gradients of light, salinity, oxygen, and sulfur that are relevant to freshwater, oceanic, hadal, and anoxic deep sea ecosystems. RESULTS Analyzing genes and metagenome-assembled genomes down the water column of Lake A in the Canadian High Arctic, we detected microbial hydrocarbon production and degradation pathways at all depths, from surface freshwaters to dark, saline, anoxic waters. In addition to Cyanobacteria, members of the phyla Flavobacteria, Nitrospina, Deltaproteobacteria, Planctomycetes, and Verrucomicrobia had pathways for alkane and alkene production, providing additional sources of biogenic hydrocarbons. Known oil-degrading microorganisms were poorly represented in the system, while long-chain hydrocarbon degradation genes were identified in various freshwater and marine lineages such as Actinobacteria, Schleiferiaceae, and Marinimicrobia. Genes involved in sulfur and nitrogen compound transformations were abundant in hydrocarbon producing and degrading lineages, suggesting strong interconnections with nitrogen and sulfur cycles and a potential for widespread distribution in the ocean. CONCLUSIONS Our detailed metagenomic analyses across water column gradients in a remote petroleum-free lake derived from the Arctic Ocean suggest that the current estimation of bacterial hydrocarbon production in the ocean could be substantially underestimated by neglecting non-phototrophic production and by not taking low oxygen zones into account. Our findings also suggest that biogenic hydrocarbons may sustain a large fraction of freshwater and oceanic microbiomes, with global biogeochemical implications for carbon, sulfur, and nitrogen cycles. Video Abstract.
Collapse
Affiliation(s)
- Adrien Vigneron
- Département de Biologie, Université Laval, Québec, QC, Canada.
- Centre d'études nordiques (CEN), Université Laval, Québec, QC, Canada.
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada.
- Takuvik Joint International Laboratory, CNRS / Université Laval, Québec, QC, Canada.
| | - Perrine Cruaud
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Université Laval, Québec, QC, Canada
| | - Connie Lovejoy
- Département de Biologie, Université Laval, Québec, QC, Canada
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Takuvik Joint International Laboratory, CNRS / Université Laval, Québec, QC, Canada
- Québec Océan, Université Laval, Québec, QC, Canada
| | - Warwick F Vincent
- Département de Biologie, Université Laval, Québec, QC, Canada
- Centre d'études nordiques (CEN), Université Laval, Québec, QC, Canada
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Takuvik Joint International Laboratory, CNRS / Université Laval, Québec, QC, Canada
| |
Collapse
|
9
|
Cheng X, Xiang X, Yun Y, Wang W, Wang H, Bodelier PLE. Archaea and their interactions with bacteria in a karst ecosystem. Front Microbiol 2023; 14:1068595. [PMID: 36814573 PMCID: PMC9939782 DOI: 10.3389/fmicb.2023.1068595] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 01/19/2023] [Indexed: 02/08/2023] Open
Abstract
Karst ecosystems are widely distributed around the world, accounting for 15-20% of the global land area. However, knowledge on microbial ecology of these systems does not match with their global importance. To close this knowledge gap, we sampled three niches including weathered rock, sediment, and drip water inside the Heshang Cave and three types of soils overlying the cave (forest soil, farmland soil, and pristine karst soil). All these samples were subjected to high-throughput sequencing of V4-V5 region of 16S rRNA gene and analyzed with multivariate statistical analysis. Overall, archaeal communities were dominated by Thaumarchaeota, whereas Actinobacteria dominated bacterial communities. Thermoplasmata, Nitrosopumilaceae, Aenigmarchaeales, Crossiella, Acidothermus, and Solirubrobacter were the important predictor groups inside the Heshang Cave, which were correlated to NH4 + availability. In contrast, Candidatus Nitrososphaera, Candidatus Nitrocosmicus, Thaumarchaeota Group 1.1c, and Pseudonocardiaceae were the predictors outside the cave, whose distribution was correlated with pH, Ca2+, and NO2 -. Tighter network structures were found in archaeal communities than those of bacteria, whereas the topological properties of bacterial networks were more similar to those of total prokaryotic networks. Both chemolithoautotrophic archaea (Candidatus Methanoperedens and Nitrosopumilaceae) and bacteria (subgroup 7 of Acidobacteria and Rokubacteriales) were the dominant keystone taxa within the co-occurrence networks, potentially playing fundamental roles in obtaining energy under oligotrophic conditions and thus maintaining the stability of the cave ecosystem. To be noted, all the keystone taxa of karst ecosystems were related to nitrogen cycling, which needs further investigation, particularly the role of archaea. The predicted ecological functions in karst soils mainly related to carbohydrate metabolism, biotin metabolism, and synthesis of fatty acid. Our results offer new insights into archaeal ecology, their potential functions, and archaeal interactions with bacteria, which enhance our understanding about the microbial dark matter in the subsurface karst ecosystems.
Collapse
Affiliation(s)
- Xiaoyu Cheng
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China,School of Environmental Studies, China University of Geosciences, Wuhan, China,Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
| | - Xing Xiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China,College of Life Science, Shangrao Normal University, Shangrao, China
| | - Yuan Yun
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China,College of Life Sciences, Nankai University, Tianjin, China
| | - Weiqi Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China,School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Hongmei Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China,School of Environmental Studies, China University of Geosciences, Wuhan, China,*Correspondence: Hongmei Wang, ✉ ; ✉
| | - Paul L. E. Bodelier
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
| |
Collapse
|
10
|
Vigneron A, Cruaud P, Guyoneaud R, Goñi-Urriza M. Into the darkness of the microbial dark matter in situ activities through expression profiles of Patescibacteria populations. Front Microbiol 2023; 13:1073483. [PMID: 36699594 PMCID: PMC9868632 DOI: 10.3389/fmicb.2022.1073483] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/05/2022] [Indexed: 01/11/2023] Open
Abstract
Patescibacteria form a highly diverse and widespread superphylum of uncultured microorganisms representing a third of the global microbial diversity. Most of our knowledge on Patescibacteria putative physiology relies on metagenomic mining and metagenome-assembled genomes, but the in situ activities and the ecophysiology of these microorganisms have been rarely explored, leaving the role of Patescibacteria in ecosystems elusive. Using a genome-centric metatranscriptomic approach, we analyzed the diel and seasonal gene transcription profiles of 18 Patescibacteria populations in brackish microbial mats to test whether our understanding of Patescibacteria metabolism allows the extrapolation of their in situ activities. Although our results revealed a circadian cycle in Patescibacteria activities, a strong streamlined genetic expression characterized the Patescibacteria populations. This result has a major consequence for the extrapolation of their physiology and environmental function since most transcribed genes were uncharacterized, indicating that the ecophysiology of Patescibacteria cannot be yet reliably predicted from genomic data.
Collapse
Affiliation(s)
- Adrien Vigneron
- IBEAS, Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France
| | | | - Rémy Guyoneaud
- IBEAS, Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France
| | - Marisol Goñi-Urriza
- IBEAS, Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France
| |
Collapse
|
11
|
Magnuson E, Altshuler I, Fernández-Martínez MÁ, Chen YJ, Maggiori C, Goordial J, Whyte LG. Active lithoautotrophic and methane-oxidizing microbial community in an anoxic, sub-zero, and hypersaline High Arctic spring. THE ISME JOURNAL 2022; 16:1798-1808. [PMID: 35396347 PMCID: PMC9213412 DOI: 10.1038/s41396-022-01233-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 03/21/2022] [Accepted: 03/29/2022] [Indexed: 05/01/2023]
Abstract
Lost Hammer Spring, located in the High Arctic of Nunavut, Canada, is one of the coldest and saltiest terrestrial springs discovered to date. It perennially discharges anoxic (<1 ppm dissolved oxygen), sub-zero (~-5 °C), and hypersaline (~24% salinity) brines from the subsurface through up to 600 m of permafrost. The sediment is sulfate-rich (1 M) and continually emits gases composed primarily of methane (~50%), making Lost Hammer the coldest known terrestrial methane seep and an analog to extraterrestrial habits on Mars, Europa, and Enceladus. A multi-omics approach utilizing metagenome, metatranscriptome, and single-amplified genome sequencing revealed a rare surface terrestrial habitat supporting a predominantly lithoautotrophic active microbial community driven in part by sulfide-oxidizing Gammaproteobacteria scavenging trace oxygen. Genomes from active anaerobic methane-oxidizing archaea (ANME-1) showed evidence of putative metabolic flexibility and hypersaline and cold adaptations. Evidence of anaerobic heterotrophic and fermentative lifestyles were found in candidate phyla DPANN archaea and CG03 bacteria genomes. Our results demonstrate Mars-relevant metabolisms including sulfide oxidation, sulfate reduction, anaerobic oxidation of methane, and oxidation of trace gases (H2, CO2) detected under anoxic, hypersaline, and sub-zero ambient conditions, providing evidence that similar extant microbial life could potentially survive in similar habitats on Mars.
Collapse
Affiliation(s)
- Elisse Magnuson
- Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Ianina Altshuler
- School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Ya-Jou Chen
- Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Catherine Maggiori
- Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | | | - Lyle G Whyte
- Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada.
| |
Collapse
|
12
|
Abstract
Walker Glacier near the northern coast of Ellesmere Island in the Canadian High Arctic (terrestrial margin of the ‘Last Ice Area’) is undergoing rapid ice attrition in response to climate change. We applied culture and molecular methods to investigate fungal diversity at the terminus of this glacier. Analysis of the mycoflora composition showed that the Walker Glacier isolates separated into two clusters: the surface of the glacier ice and the glacier foreland. The recently exposed sediments of the foreland had a lower fungal diversity and different species from those on the ice, with the exception of five species that occurred in both habitats. This loss of glacial ice in the Arctic is therefore resulting in the loss of habitats for cold-dwelling fungal species. Fungal diversity is a potentially rich biological resource of glacial ecosystems, with unique taxa. The rapid loss of these glacial habitats underscores the urgency for genomic surveys of fungal diversity in the High Arctic, and the need for further isolation of strains as well as cryopreservation of environmental micro-biome samples for future research and conservation.
Collapse
|