We present findings on the effect of nanometer-sized silica-based pores on the glass transition of aqueous solutions of lithium bis(trifluoromethane)sulfonimide(LiTFSI)and lithium difluorosulfimide(LiFSI),respectively...We present findings on the effect of nanometer-sized silica-based pores on the glass transition of aqueous solutions of lithium bis(trifluoromethane)sulfonimide(LiTFSI)and lithium difluorosulfimide(LiFSI),respectively.Our experimental results demonstrate a clear dependence of the confinement effect on the anion type,particularly for water-rich solutions,in which the precipitation of crystalized ice under cooling process induces the formation of freeze-concentrated phase confined between pore wall and core ice.As this liquid layer becomes thinner,the freeze-concentrated phase experiences glass transition at increasingly higher temperatures in solutions of LiTFSI.However,differently,for solutions of LiFSI and LiCl,this secondary confinement has a negligible effect on the glass transition of solutions confined wherein.These different behaviors emphasize the obvious difference in the dynamic properties’response of LiTFSI and LiFSI solutions to spatial confinement and particularly to the presence of the hydrophilic pore wall.展开更多
The archaeal phylum Bathyarchaeota comprises highly diversified subgroups and is considered to be one of the most abundant microorganisms on earth. The metabolic features and evolution of this phylum still remain larg...The archaeal phylum Bathyarchaeota comprises highly diversified subgroups and is considered to be one of the most abundant microorganisms on earth. The metabolic features and evolution of this phylum still remain largely unknown. In this article, a comparative metabolic analysis of 15 newly reconstructed and 36 published metagenomic assembled genomes (MAGs) spanning 10 subgroups was performed, revealing the core metabolic features of Bathyarchaeota—namely, protein, lipid, and benzoate degradation;glycolysis;and the Wood–Ljungdahl (WL) pathway, indicating an acetyl-CoA-centralized metabolism within this phylum. Furthermore, a partial tricarboxylic acid (TCA) cycle, acetogenesis, and sulfur-related metabolic pathways were found in specific subgroups, suggesting versatile metabolic capabilities and ecological functions of different subgroups. Intriguingly, most of the MAGs from the Bathy-21 and -22 subgroups, which are placed at the phylogenetic root of all bathyarchaeotal lineages and likely represent the ancient Bathyarchaeota types, were found in hydrothermal environments and encoded reverse gyrase, suggesting a hyperthermophilic feature. This work reveals the core metabolic features of Bathyarchaeota, and indicates a hot origin of this archaeal phylum.展开更多
Sputter-deposited Au/NisoFeso bilayer films were annealed in a vacuum of 5×10^-4 Pa at 523 to 723 K for 30 or 90 min. The characteristics of the bilayer films were determined by Auger electron spectroscopy, field...Sputter-deposited Au/NisoFeso bilayer films were annealed in a vacuum of 5×10^-4 Pa at 523 to 723 K for 30 or 90 min. The characteristics of the bilayer films were determined by Auger electron spectroscopy, field emission scanning electron microscopy, X- ray diffractometry, a four-point probe technique, and an alternating gradient magnetometer. When the annealing temperature and time reached 723 K and 90 min, Ni and Fe atoms markedly diffused into the Au layer. The grain size of the Au layer did not change markedly with the annealing condition. As the annealing time was 30 min and the annealing temperature exceeded 573 K, the resistance of the bilayer film increased with increasing the annealing temperature. Furthermore, the resistance of the bilayer film annealed at 723 K for 90 ,nin was lower than that of the bilayer film annealed at 723 K for 30 min. All the bilayer films showed magnetic hysteresis loops. The as-deposited bilayer film showed a hard magnetization. The bilayer film represented an easy magnetization with increasing the annealing temperature. The Au/Ni50Fe50 film that annealed at 723 K for 90 min had the lowest saturation magnetization.展开更多
110 nm-thick Au layers were sputter-deposited on unheated glasses coatedabout a 10 nm-thick and a 50 nm-thick Cr layer respectively. The Au/Cr bilayer films were annealedin a vacuum of 1 mPa at 300℃ for 2, 5 and 30 m...110 nm-thick Au layers were sputter-deposited on unheated glasses coatedabout a 10 nm-thick and a 50 nm-thick Cr layer respectively. The Au/Cr bilayer films were annealedin a vacuum of 1 mPa at 300℃ for 2, 5 and 30 min, respectively. Auger electron spectroscopy, X-raydiffraction and Field emission scanning electron microscopy were used to analyze the composition andstructure of the Au layers. The resistivity of the bilayer films was measured by using four-pointprobe technique. The adhesion of the bilayer films to the substrate was tested using tape tests. Theamount of Cr atoms diffusing into the Au layer increases with increasing the annealing time,resulting in a decrease in lattice constant and an increase in resistivity of the Au layer. Thecontent of Cr inside the Au layer grown on the thinner Cr layer is less than that grown on thethicker Cr layer. For the Au/Cr bilayer films, the lower resistivity and the good adhesion to theglass substrate can be obtained at a shorter annealing time for a thinner Cr layer.展开更多
The origin of sedimentary dolomite has become a long-standing problem in the Earth Sciences.Some carbonate minerals like ankerite have the same crystal structure as dolomite,hence their genesis may provide clues to he...The origin of sedimentary dolomite has become a long-standing problem in the Earth Sciences.Some carbonate minerals like ankerite have the same crystal structure as dolomite,hence their genesis may provide clues to help solving the dolomite problem.The purpose of this study was to probe whether microbial activity can be involved in the formation of ankerite.Bio-carbonation experiments associated with microbial iron reduction were performed in batch systems with various concentrations of Ca^(2+)(0–20 mmol/L),with a marine iron-reducing bacterium Shewanella piezotolerans WP3 as the reaction mediator,and with lactate and ferrihydrite as the respective electron donor and acceptor.Our biomineralization data showed that Ca-amendments expedited microbially-mediated ferrihydrite reduction by enhancing the adhesion between WP3 cells and ferrihydrite particles.After bioreduction,siderite occurred as the principal secondary mineral in the Ca-free systems.Instead,Ca-Fe carbonates were formed when Ca^(2+)ions were present.The CaCO_(3) content of microbially-induced Ca-Fe carbonates was positively correlated with the initial Ca2+concentration.The Ca-Fe carbonate phase produced in the 20 mmol/L Ca-amended biosystems had a chemical formula of Ca_(0.8)Fe_(1.2)(CO_(3))_(2),which is close to the theoretical composition of ankerite.This ankeritelike phase was nanometric in size and spherical,Ca-Fe disordered,and structurally defective.Our simulated diagenesis experiments further demonstrated that the resulting ankerite-like phase could be converted into ordered ankerite under hydrothermal conditions.We introduced the term“proto-ankerite”to define the Ca-Fe phases that possess near-ankerite stoichiometry but disordered cation arrangement.On the basis of the present study,we proposed herein that microbial activity is an important contributor to the genesis of sedimentary ankerite by providing the metastable Ca-Fe carbonate precursors.展开更多
The SeqCode,formally called the Code of Nomenclature of Prokaryotes Described from Sequence Data,is a new code of nomenclature in which genome sequences are the nomenclatural types for the names of prokaryotic species...The SeqCode,formally called the Code of Nomenclature of Prokaryotes Described from Sequence Data,is a new code of nomenclature in which genome sequences are the nomenclatural types for the names of prokaryotic species.While similar to the International Code of Nomenclature of Prokaryotes(ICNP)in structure and rules of priority,it does not require the deposition of type strains in international culture collections.Thus,it allows for the formation of permanent names for uncultured prokaryotes whose nearly complete genome sequences have been obtained directly from environmental DNA as well as other prokaryotes that cannot be deposited in culture collections.Because the diversity of uncultured prokaryotes greatly exceeds that of readily culturable prokaryotes,the SeqCode is the only code suitable for naming the majority of prokaryotic species.The start date of the SeqCode was January 1,2022,and the online Registry(https://seqco.del)was created to ensure valid publication of names.The SeqCode recognizes all names validly published under the ICNP before 2022.After that date,names validly published under the SeqCode compete with ICNP names for priority.As a result,species can have only one name,either from the SeqCode or ICNP,enabling effective communication and the creation of unified taxonomies of uncultured and cultured prokaryotes.The SeqCode is administered by the SeqCode Committee,which is comprised of the SeqCode Community and elected administrative components.Anyone with an interest in the systematics of prokaryotes is encouraged to join the SeqCode Community and participate in the development of this resource.展开更多
Humic-like dissolved organic matter(DOM),usually regarded as refractory,is a major component of DOM in marine sediment pore waters.However,its bio-reactivity remains poorly explored in natural environments,which makes...Humic-like dissolved organic matter(DOM),usually regarded as refractory,is a major component of DOM in marine sediment pore waters.However,its bio-reactivity remains poorly explored in natural environments,which makes its roles in supporting subsurface microbial communities and regulating long-term carbon cycling elusive.Here,the bio-reactivity of humiclike DOM was evaluated by modeled reaction rates together with its interactions with microbial communities in five sediment cores collected from the eutrophic Pearl River Estuary to the oligotrophic deep-sea basin in the northern South China Sea.We revealed contrasting relationships between humic-like DOM and microbes in the coastal and deep-sea sediments.In eutrophic coastal sediments,specific microbial groups enriched in the deep layers co-varied with humic-like DOM,while most microbial groups were significantly correlated with protein-like DOM,microbial transformation of which likely resulted in the production of humic-like DOM.On the contrary,in energy-limiting deep-sea sediments,over 70%of the microbial groups were found closely correlated with humic-like DOM,a net consumption of which was demonstrated in deep layers.The consumption of humic-like DOM in deep-sea sediments reduced its total production flux in the uppermost~5-meter layer to about one-tenth of that in coastal sediments,which could consequently decrease the refractory DOM flux to the overlying seawater and influence long-term oceanic carbon cycling.展开更多
Lignin degradation is a major process in the global carbon cycle across both terrestrial and marine ecosystems.Bathyarchaeia,which are among the most abundant microorganisms in marine sediment,have been proposed to me...Lignin degradation is a major process in the global carbon cycle across both terrestrial and marine ecosystems.Bathyarchaeia,which are among the most abundant microorganisms in marine sediment,have been proposed to mediate anaerobic lignin degradation.However,the mechanism of bathyarchaeial lignin degradation remains unclear.Here,we report an enrichment culture of Bathy-archaeia,named Candidatus Baizosediminiarchaeum ligniniphilus DL1YTT001(Ca.B.ligniniphilus),from coastal sediments that can grow with lignin as the sole organic carbon source under mesophilic anoxic conditions.Ca.B.ligniniphilus possesses and highly expresses novel methyltransferase 1(MT1,mtgB)for transferring methoxyl groups from lignin monomers to cob(I)alamin.MtgBs have no homology with known microbial methyltransferases and are present only in bathyarchaeial lineages.Heterologous expression of the mtgB gene confirmed O-demethylation activity.The mtgB genes were identified in metagenomic data sets from a wide range of coastal sediments,and they were highly expressed in coastal sediments from the East China Sea.These findings suggest that Bathyarchaeia,capable of O-demethylation via their novel and specific methyltransferases,are ubiquitous in coastal sediments.展开更多
Bathyarchaeota is believed to play a crucial role in the global carbon cycle due to its vast biomass,broad distribution,and diverse habitat.However,its physiological and metabolic features are hard to determine withou...Bathyarchaeota is believed to play a crucial role in the global carbon cycle due to its vast biomass,broad distribution,and diverse habitat.However,its physiological and metabolic features are hard to determine without pure culture.While metagenomic analyses have shown that Bathyarchaeota has a complete inorganic carbon fixation(Wood-Ljungdahl,WL)pathway,no direct functional confirmation has been reported.To explore the inorganic carbon fixation ability of Bathyarchaeota,we used lignin and sodium bicarbonate-^(13)C(NaH^(13)CO_(3))in the long-term incubation of marine sediment samples.We found that Bathyarchaeota grew continuously in the cultivation system with lignin,and its abundance increased up to 15.3 times after10 months,increasing its fraction of all archaea from 30%to 80%.We monitored theδ^(13)C of total organic carbon to identify microbial carbon fixation in the cultivation systems,finding that it increased in the first month while NaH^(13)CO_(3)was present but only increased continuously afterward when lignin was also present.Furthermore,ultracentrifugation was performed on DNA extracted from samples at different cultivation stages to separate DNA of different buoyant densities,and bathyarchaeotal and bacterial 16S ribosomal RNA(r RNA)gene abundance were quantified using qPCR.Compared to bacteria,bathyarchaeotal 16S rRNA tended to be concentrated in heavy layers after 4 months of incubation with lignin and NaH^(13)CO_(3),indicating that Bathyarchaeota DNA contained^(13)C through proliferation based on lignin utilization and NaH^(13)CO_(3)assimilation,proving the carbon fixation capacity of Bathyarchaeota.展开更多
Anaerobic oxidation of methane(AOM) plays a crucial role in controlling global methane emission. This is a microbial process that relies on the reduction of external electron acceptors such as sulfate, nitrate/nitrite...Anaerobic oxidation of methane(AOM) plays a crucial role in controlling global methane emission. This is a microbial process that relies on the reduction of external electron acceptors such as sulfate, nitrate/nitrite, and transient metal ions. In marine settings, the dominant electron acceptor for AOM is sulfate, while other known electron acceptors are transient metal ions such as iron and manganese oxides. Despite the AOM process coupled with sulfate reduction being relatively well characterized,researches on metal-dependent AOM process are few, and no microorganism has to date been identified as being responsible for this reaction in natural marine environments. In this review, geochemical evidences of metal-dependent AOM from sediment cores in various marine environments are summarized. Studies have showed that iron and manganese are reduced in accordance with methane oxidation in seeps or diffusive profiles below the methanogenesis zone. The potential biochemical basis and mechanisms for metal-dependent AOM processes are here presented and discussed. Future research will shed light on the microbes involved in this process and also on the molecular basis of the electron transfer between these microbes and metals in natural marine environments.展开更多
As a significant role for traffic management, city planning, road monitoring, GPS navigation and map updating, the technology of road extraction from a remote sensing (RS) image has been a hot research topic in rece...As a significant role for traffic management, city planning, road monitoring, GPS navigation and map updating, the technology of road extraction from a remote sensing (RS) image has been a hot research topic in recent years. In this paper, after analyzing different road features and road models, the road extraction methods were classified into the classification-based methods, knowledge-based methods, mathematical morphology, active contour model, and dynamic programming. Firstly, the road features, road model, existing difficulties and interference factors for road extraction were analyzed. Secondly, the principle of road extraction, the advantages and disadvantages of various methods and research achievements were briefly highlighted. Then, the comparisons of the different road extraction algorithms were performed, including road features, test samples and shortcomings. Finally, the research results in recent years were summarized emphatically. It is obvious that only using one kind of road features is hard to get an excellent extraction effect. Hence, in order to get good results, the road extraction should combine multiple methods according to the real applications. In the future, how to realize the complete road extraction from a RS image is still an essential but challenging and important research topic.展开更多
Methane is a potent greenhouse gas. Continental margins contain large reservoirs of methane as solid gas hydrate and the dissolved and gaseous forms of methane. Submarine methane seeps along the global continental mar...Methane is a potent greenhouse gas. Continental margins contain large reservoirs of methane as solid gas hydrate and the dissolved and gaseous forms of methane. Submarine methane seeps along the global continental margins, including the coastal seas, have been estimated to contribute 0.01 to 0.05 Gt of carbon to the atmosphere annually, accounting for between 1%and 5% of the global methane emissions to the atmosphere. Much of this methane is exhausted via microbial anaerobic methane oxidation. Methane biotransformation in the ocean has effects on global climate change. This review mainly introduces the mechanisms of methanogenesis and methane oxidation and describes new findings that will provide information that will improve the understanding of the balance in terms of the generation, migration and consumption of methane in marine environments. Moreover, this review provides new insights into methane biogeochemical cycles and the effects of marine methane budgets on global climate.展开更多
The oxygen adsorption can drastically alter the electronic properties of the two-dimensional(2D)materials,which is usually dificult to be removed.In this work,we report the ultraviolet(UV)ilumination induced desorptio...The oxygen adsorption can drastically alter the electronic properties of the two-dimensional(2D)materials,which is usually dificult to be removed.In this work,we report the ultraviolet(UV)ilumination induced desorption of the O2 molecules from the monolayer MoS2 surface by using the atmosphere dependent transport measurement,Kelvin probe microscopy,photoluminescence spectroscopy and X-ray photoelectron spectroscopy.Obvious increasing of the conductivity,rising of the Fermi level,and red shift of the photoluminescence peaks of the MoS2 were observed after the UV ilumination in vacuum,indicating the elimination of the depletion effect from the oxygen adsorption.Such parameter changes can be reversibly recovered by the subsequent O2 exposure.Furthermore,obvious decreasing of the oxygen concentration after the UV ilumination was also observed by X-ray photoelectron spectroscopy.Thus the UV induced O2 photodesorption effect is evidenced.The photo-excited charge transfer mechanism is proposed to account for the photodesorption effect.These results provide a nondestructive way to clean the MoS2 surface and manipulate the performance of the MoS2 based devices.展开更多
Copper dendrites on the copper surface were successfully prepared by electrodeposition in acidic copper sulfate aqueous solution containing ethanol. The XRD (X-ray diffraction) patterns indicate that the Cu dendrite...Copper dendrites on the copper surface were successfully prepared by electrodeposition in acidic copper sulfate aqueous solution containing ethanol. The XRD (X-ray diffraction) patterns indicate that the Cu dendrites possess fcc (face-centered cubic) crystal structure. The contact angle of the as-prepared Cu dendrites surface without palmitic acid modification is almost 0~ and the surface is completely wetted by water. After modified with palmitic acid, the Cu dendrite surface shows superhydrophobicity with a contact angle of 160~. The polarization curves reveal that the superhydrophobic Cu dendrites surface exhibits a distinct passivation phenomenon, which could provide enhanced corrosion resistance for the substrate in the aqueous solution. The weight loss measurements show that the corrosion values of superhydrophobic surface is much lower than that of the bare copper, further meaning that the as-prepared surface has the anticorrosion performance.展开更多
Geomicrobiology is a sub-discipline of geobiology and emphasizes the interaction between microorganisms and their environment on Earth. There is a need to explicitly emphasize the biogeochemical processes performed by...Geomicrobiology is a sub-discipline of geobiology and emphasizes the interaction between microorganisms and their environment on Earth. There is a need to explicitly emphasize the biogeochemical processes performed by microorganisms associated with Earth's tectonic activities, especially under the framework of the modern theory of plate tectonics. Tectonomicrobiology aims to create a better synergy between microbial and active tectonic processes. This explicit synergy should also foster better communications between solid Earth scientists and life scientists in terms of holistic Earth system dynamics at both tectonic and micro-scales.展开更多
Impact statement Microorganisms,called anaerobic methane-oxidizing archaea(ANME),can reduce a large amount of greenhouse gas methane and therefore have the potential to cool the Earth.We collected nearly all ANMEs gen...Impact statement Microorganisms,called anaerobic methane-oxidizing archaea(ANME),can reduce a large amount of greenhouse gas methane and therefore have the potential to cool the Earth.We collected nearly all ANMEs genomes in public databases and performed a comprehensive comparative genomic analysis and molecular dating.Our results show that ANMEs originated in the late Archaean to early Proterozoic eon.During this period of time,our planet Earth was experiencing the Great Oxygenation Event and Huronian Glaciation,a dramatic drop in the Earth's surface temperature.This suggests that the emergence of ANMEs may contribute to the reduction of methane at that time,which is an unappreciated potential cause that led to the Huronian Glaciation.展开更多
The archaea that can be readily cultivated in the laboratory are only a small fraction of the total diversity that exists in nature.Although molecular ecology methods,such as metagenomic sequencing,can provide valuabl...The archaea that can be readily cultivated in the laboratory are only a small fraction of the total diversity that exists in nature.Although molecular ecology methods,such as metagenomic sequencing,can provide valuable information independent of cell cultivation,it is only through cultivation-based experiments that they may be fully characterized,both for their physiological and ecological properties.Here,we report our efforts towards enriching and isolation of uncultivated archaea from marine sediments using a refined combination of conventional microbial cultivation methods.Initially,cells were retrieved from the sediment samples through a cell extraction procedure and the sediment-free mixed cells were then divided into different size-range fractions by successive filtration through 0.8µm,0.6µm and 0.2µm membranes.Archaeal 16S rRNA gene analyses indicated noticeable retention of different archaeal groups in different fractions.For each fraction,supplementation with a variety of defined substrates(e.g.,methane,sulfate,and lignin)and stepwise dilutions led to highly active enrichment cultures of several archaeal groups with Bathyarchaeota most prominently enriched.Finally,using a roll-bottle technique,three co-cultures consisting of Bathyarchaeota(subgroup-8)and a bacterial species affiliated with either Pseudomonas or Glutamicibacter were obtained.Our results demonstrate that a combination of cell extraction,size fractionation,and roll-bottle isolation methods could be a useful protocol for the successful enrichment and isolation of numerous slow-growing archaeal groups from marine sediments.展开更多
Archaea,one of the three domains of life along with Bacteria and Eukarya,contains ancient life forms such as methanogen that are observed today on Earth,and one lineage Asgard archaea is also considered the closest an...Archaea,one of the three domains of life along with Bacteria and Eukarya,contains ancient life forms such as methanogen that are observed today on Earth,and one lineage Asgard archaea is also considered the closest ancestor of Eukarya.Recently,with the development of interdisciplinary studies from Earth and Life sciences,archaeal organisms are considered to play pivotal roles in geochemical cycling in nature.However,our understanding of the attributes,origin and evolution,geochemical and ecological functions of Archaea is hampered by the scarcity of archaeal isolates,which has represented a challenge to researchers for the last 40 years.Cultivation-independent sequencing and phylogenomic analyses have demonstrated a considerable diversity of Archaea with more than 20 novel phyla.However,only four archaeal phyla have cultured representatives,leaving large gaps in our knowledge of the metabolic capabilities and ecological functions of the majority of archaeal strains identified exclusively by DNA sequencing.In this review,we summarize the discovery and development of archaeal research,highlight the knowledge gap between uncultured and cultured archaeal microbes,and call on the importance of devoting greater research efforts to archaeal cultivation.Finally,we outlined new ideas and strategic approaches,namely,(1)genome-based methods,(2)microbial network information-based methods,(3)genome-scale model-guided methods,and(4)machine learning methods,to enable the cultivation of uncultivated archaeal microbes using accumulated high-throughput sequencing data.展开更多
The hypothesis that eukaryotes originated from within the domain Archaea has been strongly supported by recent phylogenomic analyses placing Heimdallarchaeota-Wukongarchaeota branch from the Asgard superphylum as the ...The hypothesis that eukaryotes originated from within the domain Archaea has been strongly supported by recent phylogenomic analyses placing Heimdallarchaeota-Wukongarchaeota branch from the Asgard superphylum as the closest known archaeal sister-group to eukaryotes. However, our understanding is still limited in terms of the relationship between eukaryotes and archaea, as well as the evolution and ecological functions of the Asgard archaea. Here, we describe three previously unknown phylum-level Asgard archaeal lineages, tentatively named Sigyn-, Freyr-and Njordarchaeota. Additional members in Wukongarchaeota and Baldrarchaeota from distinct environments are also reported here, further expanding their ecological roles and metabolic capacities. Comprehensive phylogenomic analyses further supported the origin of eukaryotes within Asgard archaea and a new lineage Njordarchaeota was supposed as the known closest branch with the eukaryotic nuclear host lineage. Metabolic reconstruction suggests that Njordarchaeota may have a heterotrophic lifestyle with capability of peptides and amino acids utilization, while Sigynarchaeota and Freyrarchaeota also have the potentials to fix inorganic carbon via the Wood-Ljungdahl pathway and degrade organic matters. Additionally, the Ack/Pta pathway for homoacetogenesis and de novo anaerobic cobalamin biosynthesis pathway were found in Freyrarchaeota and Wukongrarchaeota,respectively. Some previously unidentified eukaryotic signature proteins for intracellular membrane trafficking system, and the homologue of mu/sigma subunit of adaptor protein complex, were identified in Freyrarchaeota. This study expands the Asgard superphylum, sheds new light on the evolution of eukaryotes and improves our understanding of ecological functions of the Asgard archaea.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974385 and 91956101).
文摘We present findings on the effect of nanometer-sized silica-based pores on the glass transition of aqueous solutions of lithium bis(trifluoromethane)sulfonimide(LiTFSI)and lithium difluorosulfimide(LiFSI),respectively.Our experimental results demonstrate a clear dependence of the confinement effect on the anion type,particularly for water-rich solutions,in which the precipitation of crystalized ice under cooling process induces the formation of freeze-concentrated phase confined between pore wall and core ice.As this liquid layer becomes thinner,the freeze-concentrated phase experiences glass transition at increasingly higher temperatures in solutions of LiTFSI.However,differently,for solutions of LiFSI and LiCl,this secondary confinement has a negligible effect on the glass transition of solutions confined wherein.These different behaviors emphasize the obvious difference in the dynamic properties’response of LiTFSI and LiFSI solutions to spatial confinement and particularly to the presence of the hydrophilic pore wall.
基金the National Natural Science Foundation of China (41525011, 91751205, and 31661143022)the Deep Carbon Observatory project.
文摘The archaeal phylum Bathyarchaeota comprises highly diversified subgroups and is considered to be one of the most abundant microorganisms on earth. The metabolic features and evolution of this phylum still remain largely unknown. In this article, a comparative metabolic analysis of 15 newly reconstructed and 36 published metagenomic assembled genomes (MAGs) spanning 10 subgroups was performed, revealing the core metabolic features of Bathyarchaeota—namely, protein, lipid, and benzoate degradation;glycolysis;and the Wood–Ljungdahl (WL) pathway, indicating an acetyl-CoA-centralized metabolism within this phylum. Furthermore, a partial tricarboxylic acid (TCA) cycle, acetogenesis, and sulfur-related metabolic pathways were found in specific subgroups, suggesting versatile metabolic capabilities and ecological functions of different subgroups. Intriguingly, most of the MAGs from the Bathy-21 and -22 subgroups, which are placed at the phylogenetic root of all bathyarchaeotal lineages and likely represent the ancient Bathyarchaeota types, were found in hydrothermal environments and encoded reverse gyrase, suggesting a hyperthermophilic feature. This work reveals the core metabolic features of Bathyarchaeota, and indicates a hot origin of this archaeal phylum.
文摘Sputter-deposited Au/NisoFeso bilayer films were annealed in a vacuum of 5×10^-4 Pa at 523 to 723 K for 30 or 90 min. The characteristics of the bilayer films were determined by Auger electron spectroscopy, field emission scanning electron microscopy, X- ray diffractometry, a four-point probe technique, and an alternating gradient magnetometer. When the annealing temperature and time reached 723 K and 90 min, Ni and Fe atoms markedly diffused into the Au layer. The grain size of the Au layer did not change markedly with the annealing condition. As the annealing time was 30 min and the annealing temperature exceeded 573 K, the resistance of the bilayer film increased with increasing the annealing temperature. Furthermore, the resistance of the bilayer film annealed at 723 K for 90 ,nin was lower than that of the bilayer film annealed at 723 K for 30 min. All the bilayer films showed magnetic hysteresis loops. The as-deposited bilayer film showed a hard magnetization. The bilayer film represented an easy magnetization with increasing the annealing temperature. The Au/Ni50Fe50 film that annealed at 723 K for 90 min had the lowest saturation magnetization.
文摘110 nm-thick Au layers were sputter-deposited on unheated glasses coatedabout a 10 nm-thick and a 50 nm-thick Cr layer respectively. The Au/Cr bilayer films were annealedin a vacuum of 1 mPa at 300℃ for 2, 5 and 30 min, respectively. Auger electron spectroscopy, X-raydiffraction and Field emission scanning electron microscopy were used to analyze the composition andstructure of the Au layers. The resistivity of the bilayer films was measured by using four-pointprobe technique. The adhesion of the bilayer films to the substrate was tested using tape tests. Theamount of Cr atoms diffusing into the Au layer increases with increasing the annealing time,resulting in a decrease in lattice constant and an increase in resistivity of the Au layer. Thecontent of Cr inside the Au layer grown on the thinner Cr layer is less than that grown on thethicker Cr layer. For the Au/Cr bilayer films, the lower resistivity and the good adhesion to theglass substrate can be obtained at a shorter annealing time for a thinner Cr layer.
基金This research was jointly supported by the National Natural Science Foundation of China(Grant Nos.42272046,42293292 and 42072336)the National Key R&D Program of China(Grant No.2022YFF0800304)the 111 Project(Grant No.BP0820004).
文摘The origin of sedimentary dolomite has become a long-standing problem in the Earth Sciences.Some carbonate minerals like ankerite have the same crystal structure as dolomite,hence their genesis may provide clues to help solving the dolomite problem.The purpose of this study was to probe whether microbial activity can be involved in the formation of ankerite.Bio-carbonation experiments associated with microbial iron reduction were performed in batch systems with various concentrations of Ca^(2+)(0–20 mmol/L),with a marine iron-reducing bacterium Shewanella piezotolerans WP3 as the reaction mediator,and with lactate and ferrihydrite as the respective electron donor and acceptor.Our biomineralization data showed that Ca-amendments expedited microbially-mediated ferrihydrite reduction by enhancing the adhesion between WP3 cells and ferrihydrite particles.After bioreduction,siderite occurred as the principal secondary mineral in the Ca-free systems.Instead,Ca-Fe carbonates were formed when Ca^(2+)ions were present.The CaCO_(3) content of microbially-induced Ca-Fe carbonates was positively correlated with the initial Ca2+concentration.The Ca-Fe carbonate phase produced in the 20 mmol/L Ca-amended biosystems had a chemical formula of Ca_(0.8)Fe_(1.2)(CO_(3))_(2),which is close to the theoretical composition of ankerite.This ankeritelike phase was nanometric in size and spherical,Ca-Fe disordered,and structurally defective.Our simulated diagenesis experiments further demonstrated that the resulting ankerite-like phase could be converted into ordered ankerite under hydrothermal conditions.We introduced the term“proto-ankerite”to define the Ca-Fe phases that possess near-ankerite stoichiometry but disordered cation arrangement.On the basis of the present study,we proposed herein that microbial activity is an important contributor to the genesis of sedimentary ankerite by providing the metastable Ca-Fe carbonate precursors.
文摘The SeqCode,formally called the Code of Nomenclature of Prokaryotes Described from Sequence Data,is a new code of nomenclature in which genome sequences are the nomenclatural types for the names of prokaryotic species.While similar to the International Code of Nomenclature of Prokaryotes(ICNP)in structure and rules of priority,it does not require the deposition of type strains in international culture collections.Thus,it allows for the formation of permanent names for uncultured prokaryotes whose nearly complete genome sequences have been obtained directly from environmental DNA as well as other prokaryotes that cannot be deposited in culture collections.Because the diversity of uncultured prokaryotes greatly exceeds that of readily culturable prokaryotes,the SeqCode is the only code suitable for naming the majority of prokaryotic species.The start date of the SeqCode was January 1,2022,and the online Registry(https://seqco.del)was created to ensure valid publication of names.The SeqCode recognizes all names validly published under the ICNP before 2022.After that date,names validly published under the SeqCode compete with ICNP names for priority.As a result,species can have only one name,either from the SeqCode or ICNP,enabling effective communication and the creation of unified taxonomies of uncultured and cultured prokaryotes.The SeqCode is administered by the SeqCode Committee,which is comprised of the SeqCode Community and elected administrative components.Anyone with an interest in the systematics of prokaryotes is encouraged to join the SeqCode Community and participate in the development of this resource.
基金supported by the National Natural Science Foundation of China(Grant Nos.42141003,41921006&41867057)the National Key Research and Development Program of China(Grant No.2020YFA0608300)+4 种基金the“Shanghai Jiao Tong University 2030”Program(Grant No.WH510244001)partially by the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Grant No.SMSEGL20SC01)the Center for Ocean Research in Hong Kong and Macao(CORECORE is a joint research center for ocean research between QNLM and HKUST)The SO269 cruise(SOCLIS-South China Sea-natural Laboratory under climatic and human induced stress,BMBF FKZ 03G0269)was a contribution to the bilateral Sino-German project MEGAPOL-Megacity’s fingerprint in Chinese marginal seas:Investigation of pollutant fingerprints and dispersal within the framework of WTZ China of the German government and was founded by BMBF(Grant No.03F0786A)。
文摘Humic-like dissolved organic matter(DOM),usually regarded as refractory,is a major component of DOM in marine sediment pore waters.However,its bio-reactivity remains poorly explored in natural environments,which makes its roles in supporting subsurface microbial communities and regulating long-term carbon cycling elusive.Here,the bio-reactivity of humiclike DOM was evaluated by modeled reaction rates together with its interactions with microbial communities in five sediment cores collected from the eutrophic Pearl River Estuary to the oligotrophic deep-sea basin in the northern South China Sea.We revealed contrasting relationships between humic-like DOM and microbes in the coastal and deep-sea sediments.In eutrophic coastal sediments,specific microbial groups enriched in the deep layers co-varied with humic-like DOM,while most microbial groups were significantly correlated with protein-like DOM,microbial transformation of which likely resulted in the production of humic-like DOM.On the contrary,in energy-limiting deep-sea sediments,over 70%of the microbial groups were found closely correlated with humic-like DOM,a net consumption of which was demonstrated in deep layers.The consumption of humic-like DOM in deep-sea sediments reduced its total production flux in the uppermost~5-meter layer to about one-tenth of that in coastal sediments,which could consequently decrease the refractory DOM flux to the overlying seawater and influence long-term oceanic carbon cycling.
基金supported financially by the Natural Science Foundation of China(Grants 42276139,42230401,42141003,41921006,92051116,91951209)2030 Project,Shanghai Jiao Tong University(Grant WH510244001)the National Postdoctoral Program for Innovative Talents(Grant No.BX20190204).
文摘Lignin degradation is a major process in the global carbon cycle across both terrestrial and marine ecosystems.Bathyarchaeia,which are among the most abundant microorganisms in marine sediment,have been proposed to mediate anaerobic lignin degradation.However,the mechanism of bathyarchaeial lignin degradation remains unclear.Here,we report an enrichment culture of Bathy-archaeia,named Candidatus Baizosediminiarchaeum ligniniphilus DL1YTT001(Ca.B.ligniniphilus),from coastal sediments that can grow with lignin as the sole organic carbon source under mesophilic anoxic conditions.Ca.B.ligniniphilus possesses and highly expresses novel methyltransferase 1(MT1,mtgB)for transferring methoxyl groups from lignin monomers to cob(I)alamin.MtgBs have no homology with known microbial methyltransferases and are present only in bathyarchaeial lineages.Heterologous expression of the mtgB gene confirmed O-demethylation activity.The mtgB genes were identified in metagenomic data sets from a wide range of coastal sediments,and they were highly expressed in coastal sediments from the East China Sea.These findings suggest that Bathyarchaeia,capable of O-demethylation via their novel and specific methyltransferases,are ubiquitous in coastal sediments.
基金supported by the State Key R&D Project of China(Grant No.2016YFA0601102)the National Natural Science Foundation of China(Grant Nos.91751205,41525011&41867057)。
文摘Bathyarchaeota is believed to play a crucial role in the global carbon cycle due to its vast biomass,broad distribution,and diverse habitat.However,its physiological and metabolic features are hard to determine without pure culture.While metagenomic analyses have shown that Bathyarchaeota has a complete inorganic carbon fixation(Wood-Ljungdahl,WL)pathway,no direct functional confirmation has been reported.To explore the inorganic carbon fixation ability of Bathyarchaeota,we used lignin and sodium bicarbonate-^(13)C(NaH^(13)CO_(3))in the long-term incubation of marine sediment samples.We found that Bathyarchaeota grew continuously in the cultivation system with lignin,and its abundance increased up to 15.3 times after10 months,increasing its fraction of all archaea from 30%to 80%.We monitored theδ^(13)C of total organic carbon to identify microbial carbon fixation in the cultivation systems,finding that it increased in the first month while NaH^(13)CO_(3)was present but only increased continuously afterward when lignin was also present.Furthermore,ultracentrifugation was performed on DNA extracted from samples at different cultivation stages to separate DNA of different buoyant densities,and bathyarchaeotal and bacterial 16S ribosomal RNA(r RNA)gene abundance were quantified using qPCR.Compared to bacteria,bathyarchaeotal 16S rRNA tended to be concentrated in heavy layers after 4 months of incubation with lignin and NaH^(13)CO_(3),indicating that Bathyarchaeota DNA contained^(13)C through proliferation based on lignin utilization and NaH^(13)CO_(3)assimilation,proving the carbon fixation capacity of Bathyarchaeota.
基金supported by the National Natural Science Foundation of China (91751205, 41525011)the National Key R&D project of China (2018YFC0310800)+1 种基金China Postdoctoral Science Foundation Grant (2018T110390)the joint Israel Science Foundation-National Natural Science Foundation of China (ISF-NSFC) (31661143022 (FW), 2561/16 (OS))
文摘Anaerobic oxidation of methane(AOM) plays a crucial role in controlling global methane emission. This is a microbial process that relies on the reduction of external electron acceptors such as sulfate, nitrate/nitrite, and transient metal ions. In marine settings, the dominant electron acceptor for AOM is sulfate, while other known electron acceptors are transient metal ions such as iron and manganese oxides. Despite the AOM process coupled with sulfate reduction being relatively well characterized,researches on metal-dependent AOM process are few, and no microorganism has to date been identified as being responsible for this reaction in natural marine environments. In this review, geochemical evidences of metal-dependent AOM from sediment cores in various marine environments are summarized. Studies have showed that iron and manganese are reduced in accordance with methane oxidation in seeps or diffusive profiles below the methanogenesis zone. The potential biochemical basis and mechanisms for metal-dependent AOM processes are here presented and discussed. Future research will shed light on the microbes involved in this process and also on the molecular basis of the electron transfer between these microbes and metals in natural marine environments.
基金financially supported by the Special Fund for Basic Scientific Research of Central Colleges(No.2013G2241019)Shaanxi Province Science and Technology Fund(No.2013KW03)Xi'an City Science and Technology Fund(No.CX1252(8))
文摘As a significant role for traffic management, city planning, road monitoring, GPS navigation and map updating, the technology of road extraction from a remote sensing (RS) image has been a hot research topic in recent years. In this paper, after analyzing different road features and road models, the road extraction methods were classified into the classification-based methods, knowledge-based methods, mathematical morphology, active contour model, and dynamic programming. Firstly, the road features, road model, existing difficulties and interference factors for road extraction were analyzed. Secondly, the principle of road extraction, the advantages and disadvantages of various methods and research achievements were briefly highlighted. Then, the comparisons of the different road extraction algorithms were performed, including road features, test samples and shortcomings. Finally, the research results in recent years were summarized emphatically. It is obvious that only using one kind of road features is hard to get an excellent extraction effect. Hence, in order to get good results, the road extraction should combine multiple methods according to the real applications. In the future, how to realize the complete road extraction from a RS image is still an essential but challenging and important research topic.
基金supported by the State Key R & D Project of China (Grant No. 2016YFA0601102)the National Natural Science Foundation of China (Grant Nos. 41525011, 91228201 & 91428308)the National Special Project on Gas Hydrate of China (Grant Nos. GZH201100311 & DD20160217)
文摘Methane is a potent greenhouse gas. Continental margins contain large reservoirs of methane as solid gas hydrate and the dissolved and gaseous forms of methane. Submarine methane seeps along the global continental margins, including the coastal seas, have been estimated to contribute 0.01 to 0.05 Gt of carbon to the atmosphere annually, accounting for between 1%and 5% of the global methane emissions to the atmosphere. Much of this methane is exhausted via microbial anaerobic methane oxidation. Methane biotransformation in the ocean has effects on global climate change. This review mainly introduces the mechanisms of methanogenesis and methane oxidation and describes new findings that will provide information that will improve the understanding of the balance in terms of the generation, migration and consumption of methane in marine environments. Moreover, this review provides new insights into methane biogeochemical cycles and the effects of marine methane budgets on global climate.
基金This work is supported by the National Natural Science Foundation of China(Nos.11074142 and 11021464)Collaborative Innovation Center of Weak Signal-Detecting Materials and Devices Integration of Anhui University(No.01001795-201601)+1 种基金Fundam ental Research Funds for the Central Universities(No.FRP-TP-18-076A1)the China Postdoctoral Science Foundation(No.2017M610857).
文摘The oxygen adsorption can drastically alter the electronic properties of the two-dimensional(2D)materials,which is usually dificult to be removed.In this work,we report the ultraviolet(UV)ilumination induced desorption of the O2 molecules from the monolayer MoS2 surface by using the atmosphere dependent transport measurement,Kelvin probe microscopy,photoluminescence spectroscopy and X-ray photoelectron spectroscopy.Obvious increasing of the conductivity,rising of the Fermi level,and red shift of the photoluminescence peaks of the MoS2 were observed after the UV ilumination in vacuum,indicating the elimination of the depletion effect from the oxygen adsorption.Such parameter changes can be reversibly recovered by the subsequent O2 exposure.Furthermore,obvious decreasing of the oxygen concentration after the UV ilumination was also observed by X-ray photoelectron spectroscopy.Thus the UV induced O2 photodesorption effect is evidenced.The photo-excited charge transfer mechanism is proposed to account for the photodesorption effect.These results provide a nondestructive way to clean the MoS2 surface and manipulate the performance of the MoS2 based devices.
基金supported by the Creative Team of the Liaoning Higher Education Institutions of China (No. LT20100055)
文摘Copper dendrites on the copper surface were successfully prepared by electrodeposition in acidic copper sulfate aqueous solution containing ethanol. The XRD (X-ray diffraction) patterns indicate that the Cu dendrites possess fcc (face-centered cubic) crystal structure. The contact angle of the as-prepared Cu dendrites surface without palmitic acid modification is almost 0~ and the surface is completely wetted by water. After modified with palmitic acid, the Cu dendrite surface shows superhydrophobicity with a contact angle of 160~. The polarization curves reveal that the superhydrophobic Cu dendrites surface exhibits a distinct passivation phenomenon, which could provide enhanced corrosion resistance for the substrate in the aqueous solution. The weight loss measurements show that the corrosion values of superhydrophobic surface is much lower than that of the bare copper, further meaning that the as-prepared surface has the anticorrosion performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.41530105,41373072,91628301&U1606401)the Chinese Academy of Sciences(Grant Nos.Y4SL021001&QYZDY-SSW-DQC005)the Southern University of Science and Technology(Grant No.Y01316209)
文摘Geomicrobiology is a sub-discipline of geobiology and emphasizes the interaction between microorganisms and their environment on Earth. There is a need to explicitly emphasize the biogeochemical processes performed by microorganisms associated with Earth's tectonic activities, especially under the framework of the modern theory of plate tectonics. Tectonomicrobiology aims to create a better synergy between microbial and active tectonic processes. This explicit synergy should also foster better communications between solid Earth scientists and life scientists in terms of holistic Earth system dynamics at both tectonic and micro-scales.
基金the National Natural Science Foundation of China for funding(grant Nos.41902313,92051116,41921006,42141003,91428308).
文摘Impact statement Microorganisms,called anaerobic methane-oxidizing archaea(ANME),can reduce a large amount of greenhouse gas methane and therefore have the potential to cool the Earth.We collected nearly all ANMEs genomes in public databases and performed a comprehensive comparative genomic analysis and molecular dating.Our results show that ANMEs originated in the late Archaean to early Proterozoic eon.During this period of time,our planet Earth was experiencing the Great Oxygenation Event and Huronian Glaciation,a dramatic drop in the Earth's surface temperature.This suggests that the emergence of ANMEs may contribute to the reduction of methane at that time,which is an unappreciated potential cause that led to the Huronian Glaciation.
基金We would like to thank Dr.Tiantian Yu for valuable comments in modifying the paper and Dr.Mingyang Niu for help with the Archaeal 16S rRNA gene analyses.This work is supported by State Key Research and Development Project of China Grant(2016YFA0601102)China Ocean Mineral Resources R&D Association(COMRA)project(DY135-B2-12)+1 种基金the Natural Science Foundation of China(Grants No.41525011,91751205)the Senior User Project of RV KEXUE(KEXUE2019GZ06).
文摘The archaea that can be readily cultivated in the laboratory are only a small fraction of the total diversity that exists in nature.Although molecular ecology methods,such as metagenomic sequencing,can provide valuable information independent of cell cultivation,it is only through cultivation-based experiments that they may be fully characterized,both for their physiological and ecological properties.Here,we report our efforts towards enriching and isolation of uncultivated archaea from marine sediments using a refined combination of conventional microbial cultivation methods.Initially,cells were retrieved from the sediment samples through a cell extraction procedure and the sediment-free mixed cells were then divided into different size-range fractions by successive filtration through 0.8µm,0.6µm and 0.2µm membranes.Archaeal 16S rRNA gene analyses indicated noticeable retention of different archaeal groups in different fractions.For each fraction,supplementation with a variety of defined substrates(e.g.,methane,sulfate,and lignin)and stepwise dilutions led to highly active enrichment cultures of several archaeal groups with Bathyarchaeota most prominently enriched.Finally,using a roll-bottle technique,three co-cultures consisting of Bathyarchaeota(subgroup-8)and a bacterial species affiliated with either Pseudomonas or Glutamicibacter were obtained.Our results demonstrate that a combination of cell extraction,size fractionation,and roll-bottle isolation methods could be a useful protocol for the successful enrichment and isolation of numerous slow-growing archaeal groups from marine sediments.
基金supported by the State Key R&D Project of China(Grant No.2016YFA0601102)the China Ocean Mineral Resources R&D Association(Grant No.DY135-B2-12)+6 种基金COMRA Project DY135-B2-12the National Nature Science Foundation of China(Grant Nos.41525011,41921006,41902313,91751205&92051116)the Natural Science Foundation of Shanghai(Grant No.20ZR1428000)the Shanghai Jiao Tong University Interdisciplinary Grant(Grant No.20CX-01)Japan Society for the Promotion of Science(JSPS)(KAKENHI Grant 18H05295)This is also a contribution to the Center for Ocean Mega-Science,Chinese Academy of Sciences,the Senior User Project of RV KEXUE(Grant No.KEXUE2019GZ06)the International Center for Deep-life Investigation(IC-DLI).
文摘Archaea,one of the three domains of life along with Bacteria and Eukarya,contains ancient life forms such as methanogen that are observed today on Earth,and one lineage Asgard archaea is also considered the closest ancestor of Eukarya.Recently,with the development of interdisciplinary studies from Earth and Life sciences,archaeal organisms are considered to play pivotal roles in geochemical cycling in nature.However,our understanding of the attributes,origin and evolution,geochemical and ecological functions of Archaea is hampered by the scarcity of archaeal isolates,which has represented a challenge to researchers for the last 40 years.Cultivation-independent sequencing and phylogenomic analyses have demonstrated a considerable diversity of Archaea with more than 20 novel phyla.However,only four archaeal phyla have cultured representatives,leaving large gaps in our knowledge of the metabolic capabilities and ecological functions of the majority of archaeal strains identified exclusively by DNA sequencing.In this review,we summarize the discovery and development of archaeal research,highlight the knowledge gap between uncultured and cultured archaeal microbes,and call on the importance of devoting greater research efforts to archaeal cultivation.Finally,we outlined new ideas and strategic approaches,namely,(1)genome-based methods,(2)microbial network information-based methods,(3)genome-scale model-guided methods,and(4)machine learning methods,to enable the cultivation of uncultivated archaeal microbes using accumulated high-throughput sequencing data.
基金supported by the National Natural Science Foundation of China (91751205, 41921006, 41902313, 92051116)the China Ocean Mineral Resources R&D Association (COMRA) project (DY135-B2-12)+1 种基金the National Key Research and Development Project of China (2018YFC0310803)the Senior User Project of RV KEXUE (KEXUE2019GZ06)
文摘The hypothesis that eukaryotes originated from within the domain Archaea has been strongly supported by recent phylogenomic analyses placing Heimdallarchaeota-Wukongarchaeota branch from the Asgard superphylum as the closest known archaeal sister-group to eukaryotes. However, our understanding is still limited in terms of the relationship between eukaryotes and archaea, as well as the evolution and ecological functions of the Asgard archaea. Here, we describe three previously unknown phylum-level Asgard archaeal lineages, tentatively named Sigyn-, Freyr-and Njordarchaeota. Additional members in Wukongarchaeota and Baldrarchaeota from distinct environments are also reported here, further expanding their ecological roles and metabolic capacities. Comprehensive phylogenomic analyses further supported the origin of eukaryotes within Asgard archaea and a new lineage Njordarchaeota was supposed as the known closest branch with the eukaryotic nuclear host lineage. Metabolic reconstruction suggests that Njordarchaeota may have a heterotrophic lifestyle with capability of peptides and amino acids utilization, while Sigynarchaeota and Freyrarchaeota also have the potentials to fix inorganic carbon via the Wood-Ljungdahl pathway and degrade organic matters. Additionally, the Ack/Pta pathway for homoacetogenesis and de novo anaerobic cobalamin biosynthesis pathway were found in Freyrarchaeota and Wukongrarchaeota,respectively. Some previously unidentified eukaryotic signature proteins for intracellular membrane trafficking system, and the homologue of mu/sigma subunit of adaptor protein complex, were identified in Freyrarchaeota. This study expands the Asgard superphylum, sheds new light on the evolution of eukaryotes and improves our understanding of ecological functions of the Asgard archaea.