Figure 4 - uploaded by Sarah Siu
Content may be subject to copyright.
![Role of archaella in attachment of Archaea to surfaces and other cells. Scanning electron micrograph of M. maripaludis attached to silicon wafer via thick cables of archaella (thick arrows) which can unwind to individual archaellar filaments (thin arrows). Bar = 100 nm ( B ). Connection of M. maripaludis cells to each other and underlying nickel EM grid via archaellar bundles. ( A ) and ( B ) reprinted from [31]. Bar = 100 nm ( C ). Scanning electron micrograph showing attachment of Mcc. villosus cells to a surface and to other cells via bundles of archaella. Bar = 1 μm. Courtesy of Gerhard Wanner, University of Munich, Germany.](profile/Sarah-Siu/publication/236324791/figure/fig3/AS:299342217924611@1448380154255/Role-of-archaella-in-attachment-of-Archaea-to-surfaces-and-other-cells-Scanning-electron.png)
Role of archaella in attachment of Archaea to surfaces and other cells. Scanning electron micrograph of M. maripaludis attached to silicon wafer via thick cables of archaella (thick arrows) which can unwind to individual archaellar filaments (thin arrows). Bar = 100 nm ( B ). Connection of M. maripaludis cells to each other and underlying nickel EM grid via archaellar bundles. ( A ) and ( B ) reprinted from [31]. Bar = 100 nm ( C ). Scanning electron micrograph showing attachment of Mcc. villosus cells to a surface and to other cells via bundles of archaella. Bar = 1 μm. Courtesy of Gerhard Wanner, University of Munich, Germany.
Source publication
Organisms representing diverse subgroupings of the Domain Archaea are known to possess unusual surface structures. These can include ones unique to Archaea such as cannulae and hami as well as archaella (archaeal flagella) and various types of pili that superficially resemble their namesakes in Bacteria, although with significant differences. Major...
Context in source publication
Context 1
... P. furiosus uses archaella to adhere onto cells of another archaeon, Methanopyrus kandleri, to form a bi-species biofilm [37]. Cable-like structures composed of archaella were also shown to mediate cell-cell contact and abiotic surface adhesion in M. villosus [103] and M. maripaludis [31] (Figure 4). . Role of archaella in attachment of Archaea to surfaces and other cells. ...
Similar publications
Significance
To avoid the mucosal barrier and attach to the intestinal epithelium, enteric pathogens have evolved a unique proteinaceous fiber called type IVb pilus (T4bP). Despite its importance for bacterial pathogenesis, little is known about the adhesion mechanisms of T4bP, especially regarding the role of the minor pilin subunit located at its...
ABSTRACT
Acinetobacter baumannii is a Gram-negative, opportunistic pathogen. Recently, multiple A. baumannii genomes have been sequenced; these data have led to the identification of many genes predicted to encode proteins required for the biogenesis of type IV pili (TFP). However, there is no experimental evidence demonstrating that A. baumannii...
Neisseria gonorrhoeae is the causative agent of gonorrhea and an obligate pathogen of humans. The Opa proteins of these bacteria are known to mediate attachment and internalization by host cells, including neutrophils. The Opa protein repertoire of a typical N. gonorrhoeae isolate is encoded on ∼11 genes distributed throughout the chromosome and is...
Type IV pili are widely expressed among Gram-negative bacteria, where they are involved in biofilm formation, serve in the transfer of DNA, motility and in the bacterial attachment to various surfaces. Type IV pili in Shewanella oneidensis are also supposed to play an important role in extracellular electron transfer by the attachment to sediments...
Enterotoxigenic Escherichia coli (ETEC) infection is one of the major causes contributing to the development of diarrhoea and mortality in new born, suckling and newly weaned piglets. To date, no preventive / treatme nt strategy showed promising results, which could be due to the lack of potent vaccines, and / or due to the development of resistanc...
Citations
... Further, pili and fimbriae, hair-like structures, are involved in adhesion to surfaces and conjugation [88]. For instance, Methanococcus voltae has type IV pili that help it to attach to surfaces [90]; Methanocaldococcus jannaschii, produces long, filamentous pili, allowing them to interact with their environment (motility), form complex communities with other microorganisms (adhesion to surfaces and cells), and adapt to changing conditions (conjugation) [91]. H. volcanii, Sulfolobus spp., and Thermococcus spp. ...
Purpose of Review
Since the introduction of Archaea as a new domain of life more than 45 years ago, progress in their phylogenetic classification and knowledge of their exclusive biological characteristics has identified archaea as unique microorganisms which are widespread in extreme but also in various moderate ecosystems, including eukaryotic hosts. However, archaea are still neglected players within microbiomes, and research on archaea-bacteria interactions is still in its infancy due to methodological challenges.
Recent Findings
This review summarizes the current knowledge of archaea as components within microbiomes and focuses on their interactions with their bacterial neighbors and the principles of archaeal interactions.
Summary
Archaea are common constituents of animal and human microbiomes, which are dominated by Euryarchaeota. The gastrointestinal tract is the most studied body site, where archaea account for up to 4% of all microorganisms, primarily represented by methanogens. No archaeal pathogen has yet been identified, although methanogens are hypothesized to be indirectly involved in pathogenicity. Archaeal interactions comprise symbiotic relationships, and the cell membrane and wall might be as crucial as quorum sensing/quenching for these interactions. Particularly, syntrophic interactions under energy-deficiency stress seem to be an essential strategy for archaea. However, more research is urgently needed to discover how archaea sense their environment, compete with bacteria, and interact within complex microbiomes associated with multicellular organisms.
... Therefore, Nucleotidisoterales may use different strategies to promote cell-cell interactions. Studies have shown that pili and archaella, as well as certain surface proteins, likely contribute to cell surface attachment and interaction between symbionts and hosts [30,31]. Unlike other Ca. ...
Archaea are important microbes that contribute to biogeochemical cycling. Most archaea are difficult to grow in the lab, which has limited our ability to understand them, but new genetic sequencing and analysis tools allow researchers to study microbes without cultivating them. Recently, a team of researchers used such tools to identify new potential archaeal genomes from stratified salt crust. They identified three new genomes that likely represent a new phylogenetic order within the phylum Ca. Nanohaloarchaeota, and the researchers named this order Nucleotidisoterales. Examining the genes these archaea possess revealed key information about their potential functions and behavior. First, this order probably cannot use carbohydrates for energy and instead recycles and uses nucleotides (e.g., DNA bases) and proteins. They also appear to employ the same techniques as other Ca. Nanohaloarchaeota from saline habitats to avoid collapsing due to the salt in their environment. This new order had a high proportion of acidic amino acids in their proteins, unlike Ca. Nanohaloarchaeota from geothermal environments, which favor basic amino acids to resist the extreme heat. While more research is needed to confirm these potential ecological functions, this study adds to our understanding of this now expanded phylum.
... Structural studies have provided support for this hypothesis, showing that BT4Ps and AFFs share the N-terminal αhelical domain and are processed in a similar way (6,(13)(14)(15)(16)(17)(18). It has been shown that archaeal flagellins share a more recent common ancestor with AT4Ps and, besides the N-terminal αhelical domain, both have a C-terminal immunoglobulin (Ig)-like domain, which has no homology with the C-terminal domain present in BT4P (19)(20)(21)(22). ...
Flagellar motility has independently arisen three times during evolution: in bacteria, archaea, and eukaryotes. In prokaryotes, the supercoiled flagellar filaments are composed largely of a single protein, bacterial or archaeal flagellin, although these two proteins are not homologous, while in eukaryotes, the flagellum contains hundreds of proteins. Archaeal flagellin and archaeal type IV pilin are homologous, but how archaeal flagellar filaments (AFFs) and archaeal type IV pili (AT4Ps) diverged is not understood, in part, due to the paucity of structures for AFFs and AT4Ps. Despite having similar structures, AFFs supercoil, while AT4Ps do not, and supercoiling is essential for the function of AFFs. We used cryo-electron microscopy to determine the atomic structure of two additional AT4Ps and reanalyzed previous structures. We find that all AFFs have a prominent 10-strand packing, while AT4Ps show a striking structural diversity in their subunit packing. A clear distinction between all AFF and all AT4P structures involves the extension of the N-terminal α-helix with polar residues in the AFFs. Additionally, we characterize a flagellar-like AT4P from Pyrobaculum calidifontis with filament and subunit structure similar to that of AFFs which can be viewed as an evolutionary link, showing how the structural diversity of AT4Ps likely allowed for an AT4P to evolve into a supercoiling AFF.
... It is The copyright holder for this preprint this version posted May 12, 2023. ; https://doi.org/10.1101/2023.05.12.540504 doi: bioRxiv preprint diatom-associated prokaryotic community (Herfort et al. 2007, Jarrell et al. 2013, Bižić-Ionescu et al. 377 2015. 378 ...
The cell surfaces of phytoplankton algae including diatoms are usually colonized by specific bacterial populations which interact with and affect growth of the host species. Catalyzed Reported Deposition Fluorescence in situ Hybridizazion (CARD-FISH) is a well-suited technique to visualize and identify algal-associated bacterial cells. Autofluorescence and the strongly structured cell surface of the algal cell make it difficult to quantify distinct populations of the colonizing bacterial communities. To overcome these limitations, we adopted a CARD-FISH method to this specific application by reducing the algal autofluorescence by an extra ethanol treatment and by stacking epifluorescence micrographs taken at different focal planes and merging them into a composite image. Cells of the diatom Thalassiosira rotula were used as host and incubated with a consortium of different bacterial strains and a natural bacterial community. Samples were concentrated either by filtration onto polycarbonate membranes or by centrifugation and analyzed with probes CF319a, GAM42a and ROS536. The results showed easily quantifiable bacterial cells and did not reveal any significant differences in the abundance of diatom-associated bacterial populations assessed by both methods. Our CARD-FISH protocol persuasively demonstrated that bacterial populations can be easily and reliably enumerated on diatom cells and presumably also on other algal cells and autotrophic biofilms.
... It is The copyright holder for this preprint this version posted March 6, 2023. ; https://doi.org/10.1101/2023.03.06.531322 doi: bioRxiv preprint fimbriae, hami, cannulae, bindosomes, etc. (Jarrell and Albers, 2012;Jarrell et al., 2013). Usually, these structures were found by using electron microscope observations. ...
In present study, we describe “ ta t- fi mbriae (tafi)” – a novel type of archaeal surface appendages isolated from haloarchaeon Haloarcula hispanica . These fi lamental structures are unique because they are formed of protein subunits secreted through the t win- a rginine translocation pathway (Tat-pathway), in contrast to well-known archaeal surface filamentous structures secreted by the general secretory pathway (Sec-pathway). No cases of the role of Tat-pathway in the assembly of archaeal and bacterial filamentous structures have been described to date. “Tafi” are the first example of such structures. The precursor of the major tafi protein subunit TafA contains the N-terminal signal peptide carrying a twin-arginine consensus motif and fimbria-forming mature TafA lacks this signal peptide. We analyzed the gene neighborhood of the tafA homologues in the known haloarchaeal genomes and found a conservative cluster of seven associated genes tafA, B, C, D, E, F, G . We assume that all of them take part in the tafi synthesis. TafC and TafE proteins, whose precursor sequences also contain twin-arginine motifs, were detected as minor components of tafi. TafE protein is structurally similar to TafA, while TafC contains a TafA-like N-terminal domain and a C-terminal “laminin G-like” domain capable of functioning as an adhesin. TafD is annotated as a signal peptidase I. The functions of TafB, TafF and TafG are not known yet. This study demonstrated that Δ tafA and Δ tafD deletion mutant strains synthesized archaella and not tafi, and only tafi were detected in Δ arlK (gene of common archaellin/pilin signal peptidase) deletion strain. It was shown that the expression of complete Har. hispanica taf -gene cluster in a heterologous host Haloferax volcanii that does not have similar genes leads to synthesis of recombinant tafi structures similar to the native ones. The tafi function remains elusive, but our preliminary data suggest that these structures may be involved in cell adhesion to different surfaces or substrates.
... According to Kataria (2016), protozoa symbiotically with methanogens convert CO 2 into CH 4 . The same effect between cineol and galangal essential oil on protozoa and Archea is pos sible because cineol with a cyclic ether structure can bind polysaccharides and Archea cell wall proteins (Jarrell et al. 2013). Furthermore, with its hydrophobic nature, cineole more easily crosses the plasma membrane of the protozoa and causes mitochondrial swelling. ...
The study aimed to evaluate the effect of administering galangal essential oil (EO) on the abundance of rumen bacteria using the 16s rRNA method. The treatments included a control (no EO addition), galangal EO (30, 60, 120 µL), and cineole (5 µL). The treatments were assessed using a 48‐hour in vitro batch culture of rumen fluid containing a 60:40 ratio of forage to concentrate. For amplification of the prokaryotes (bacteria and archaea) in region V4, 16s rRNA primer 5’GTGCCAGCMGCCGCGTAA, GGACTACHVGGGTWTCTAAT3’ was employed. The data for rumen microbial abundance were analysed descriptively, while the data for rumen microbial diversity were obtained from the report on the Next Generation Sequencing Method. The microbial composition of each sample was tested for operational taxonomic units (OTUs) with a 97% identity rate on a valid label. The 16S rRNA gene sequencing yielded a total of 3,977 OTUs. Adding galangal and cineole EOs resulted in the same variation of the Shannon index. The population index (chao1 index) was highest when 60 µL of galangal EO was added, compared to 30 and 120 µL of galangal EO and cineole. In addition, providing 60 µL of galangal EO decreased the abundance of Prevotella ruminicola compared to the control and cineole doses. The addition of galangal EO also led to a decline in the number of Methanobacteriales. The population of the fibre‐degrading bacteria group (Ruminococcus albus and Ruminococcus flavefaciens) was higher in a dose of galangal EO than the control and cineole. Therefore, it can be concluded that the effective dose of galangal EO, i.e. 60 µL/300 mg (DM feed) in vitro, can reduce the abundance of Prevotella bacteria and methanogens.
... Therefore, Nucleotidisoterales may use different strategies to promote cell-cell interactions. Studies have shown that pili and archaella, as well as certain surface proteins, likely contribute to cell surface attachment and interaction between symbionts and hosts [30,31]. Unlike other Ca. ...
Background
Candidatus Nanohaloarchaeota, an archaeal phylum within the DPANN superphylum, is characterized by limited metabolic capabilities and limited phylogenetic diversity and until recently has been considered to exclusively inhabit hypersaline environments due to an obligate association with Halobacteria. Aside from hypersaline environments, Ca. Nanohaloarchaeota can also have been discovered from deep-subsurface marine sediments.
Results
Three metagenome-assembled genomes (MAGs) representing a new order within the Ca. Nanohaloarchaeota were reconstructed from a stratified salt crust and proposed to represent a novel order, Nucleotidisoterales. Genomic features reveal them to be anaerobes capable of catabolizing nucleotides by coupling nucleotide salvage pathways with lower glycolysis to yield free energy. Comparative genomics demonstrated that these and other Ca. Nanohaloarchaeota inhabiting saline habitats use a “salt-in” strategy to maintain osmotic pressure based on the high proportion of acidic amino acids. In contrast, previously described Ca. Nanohaloarchaeota MAGs from geothermal environments were enriched with basic amino acids to counter heat stress. Evolutionary history reconstruction revealed that functional differentiation of energy conservation strategies drove diversification within Ca. Nanohaloarchaeota, further leading to shifts in the catabolic strategy from nucleotide degradation within deeper lineages to polysaccharide degradation within shallow lineages.
Conclusions
This study provides deeper insight into the ecological functions and evolution of the expanded phylum Ca. Nanohaloarchaeota and further advances our understanding on the functional and genetic associations between potential symbionts and hosts.
6R3_PbsEzFSPy16NiyaaD4Video Abstract
... The structure of archaella from M. hungatei has been recently investigated in detail with cryo-EM imaging (25) and has been proven to demonstrate electrical conductivity (26). Archaella resemble bacterial type IV pili and are responsible for the chemotactic movement of the cell in a carbon substrate gradient or toward a growth-limiting electron donor (H 2 ) (27). There is a documented chemotactic response of M. hungatei toward acetate (28), which is exponentially increased up until 20 mM acetate in media. ...
Syntrophic anaerobic consortia comprised of fatty acid-degrading bacteria and hydrogen/formate-scavenging methanogenic archaea are of central importance for balanced and resilient natural and manufactured ecosystems: anoxic sediments, soils, and wastewater treatment bioreactors. Previously published studies investigated interaction between the syntrophic bi-cultures, but little information is available on the influence of fermentative bacteria on syntrophic fatty acid oxidation, even though fermentative organisms are always present together with syntrophic partners in the above-mentioned ecosystems. Here, we present experimental observations of stimulated butyrate oxidation and methane generation by a coculture of Syntrophomonas wolfei with any of the following methanogens: Methanospirillum hungatei, Methanobrevibacter arboriphilus, or Methanobacterium formicicum due to the addition of a fermentative Trichococcus flocculiformis strain ES5. The addition of T. flocculiformis ES5 to the syntrophic cocultures led to an increase in the rates of butyrate consumption (120%) and volumetric methane production (150%). Scanning electron microscopy of the most positively affected coculture (S. wolfei, M. hungatei, and T. flocculiformis ES5) revealed a tendency of T. flocculiformis ES5 to aggregate with the syntrophic partners. Analysis of coculture's proteome with or without addition of the fermentative bacterium points to a potential link with signal transducing systems of M. hungatei, as well as activation of additional butyryl coenzyme A dehydrogenase and an electron transfer flavoprotein in S. wolfei. IMPORTANCE Results from the present study open doors to fascinating research on complex microbial cultures in anaerobic environments (of biotechnological and ecological relevance). Such studies of defined mixed populations are critical to understanding the highly intertwined natural and engineered microbial systems and to developing more reliable and trustable metabolic models. By investigating the existing cultured microbial consortia, like the ones described here, we can acquire knowledge on microbial interactions that go beyond "who feeds whom" relations but yet benefit the parties involved. Transfer of signaling compounds and stimulation of gene expression are examples of indirect influence that members of mixed communities can exert on each other. Understanding such microbial relationships will enable development of new sustainable biotechnologies with mixed microbial cocultures and contribute to the general understanding of the complex natural microbial interactions.
... En bacterias Gram negativas, el cuerpo basal, de manera general consta de una barra central y tres anillos de proteínas llamados L (para lipopolisacárido), P (para peptidoglicano) y MS (membrana/supramembrana). Los anillos L y P están incrustados dentro de la membrana externa y las capas de peptidoglicanos, mientras que el anillo MS esta insertado en la porción de la membrana interna (Homma et al., 1990, Fernández and Berenguer, 2000, Van Gerven et al., 2011, Jarrell et al., 2013. ...
Background: The essential oils of plants and active principles (terpenoids) have antimicrobial effect, since they interact directly with the bacterial membrane causing the leakage of ions and other cytoplasmic compounds, as well as inhibiting the development of mobility and adhesion structures (flagella and fimbriae) in bacteria. Objective: To determine the inhibition of mobility in bacteria from terpenoid compounds and essential oils of plants. Methodology: The essential oil was extracted by hydrodistillation of the plants Cinnamomum zeylanicum, Syzygium aromaticum, Eucalyptus spp, Mentha spicata, Origanum vulgare and Salvia rosmarinus. The terpenoids: carvacrol, limonene, linalol, terpinene and thymol were identified by gas chromatography. Inhibition of mobility was evaluated in SIM medium. Statistical analysis was performed using descriptive statistics and main components (PC), from these data they were graphically contrasted to group the treatments that were able to inhibit mobility. Results: The bacteria in order of sensitivity affected by each of the terpenoids and essential oils of plants were Clostridium spp, with 76.2%; E. coli (71.45%) and Salmonella spp (57.1%), so the Pseudomona spp bacteria was the most resistant, presenting a total inhibition percentage of 47.6%. Carvacrol acted as an inhibitor at a concentration of 0.75 mg mL-1 in Clostridium spp and E. coli. Limonene, linalol and thymol, affected mobility in concentrations 0.05, 0.15, 0.75 mg mL-1 , on Clostridium spp, E. coli and Salmonella spp. The CP analysis showed the highest correlation of 0.9956 for Pseudomona spp. Implications: The terpeniod compounds and essential oils of plants are an alternative for the synthesis of antibacterial active principles. Conclusions: The inhibition of mobility in Clostridium spp, Escherichia coli, Salmonella spp and Pseudomona spp was presented at a concentration of 0.75 mg mL-1 for the terpenoid compounds limonene, linalol and thymol, as well as in the essential oils of peppermint and oregano. RESUMEN Antecedentes: Los aceites esenciales de plantas y principios activos (terpenoides) tienen efecto antimicrobiano, ya que interactúan directamente con la membrana bacteriana provocando la fuga de iones y otros compuestos citoplasmáticos, así como inhibir el desarrollo de estructuras de movilidad y adhesión en bacterias (flagelos y fimbrias). Objetivo: Determinar la inhibición de movilidad en bacterias a partir de compuestos terpenoides y aceites esenciales de plantas. Metodología: Se extrajo el aceite esencial por hidrodestilación de las plantas Cinnamomum zeylanicum, Syzygium aromaticum, Eucalyptus spp, Mentha spicata, Origanum vulgare y Salvia rosmarinus. Se identificaron los terpenoides: carvacrol, limoneno, linalol, terpineno y timol por cromatografía de gases. La inhibición de movilidad fue evaluada en medio SIM. El análisis estadístico se realizó mediante estadística descriptiva y componentes principales (CP), a partir de estos datos se contrastaron gráficamente para agrupar los tratamientos que fueron capaces de inhibir †
... While evolutionarily conserved type IV pili are required for surface adhesion in many organisms (8), as analyzed, e.g., through simple atmosphere-liquid interface (ALI) assays in standing cultures, the use of specific pilins can vary depending on the environmental conditions (2,9,10). Furthermore, while bacterial flagella and their archaeal counterparts (archaella) facilitate the binding to surfaces in some species (11), surface attachment in other species, like the model haloarchaeon Haloferax volcanii, appears to be independent of archaella (12). However, the involvement of type IV pili, archaella, and other cell surface structures in attachment and biofilm formation may depend on the environmental conditions under which ALI assays are performed. ...
Most microorganisms exist in biofilms, which comprise aggregates of cells surrounded by an extracellular matrix that provides protection from external stresses. Based on the conditions under which they form, biofilm structures vary in significant ways. For instance, biofilms that develop when microbes are incubated under static conditions differ from those formed when microbes encounter the shear forces of a flowing liquid. Moreover, biofilms develop dynamically over time. Here, we describe a cost-effective, 3D-printed coverslip holder that facilitates surface adhesion assays under a broad range of standing and shaking culture conditions. This multi-panel adhesion (mPAD) mount further allows cultures to be sampled at multiple time points, ensuring consistency and comparability between samples and enabling analyses of the dynamics of biofilm formation. As a proof of principle, using the mPAD mount for shaking, oxic cultures, we confirm previous flow chamber experiments showing that Pseudomonas aeruginosa wild type and a phenazine deletion mutant (Δ phz ) form biofilms with similar structure but reduced density in the mutant strain. Extending this analysis to anoxic conditions, we reveal that microcolony and biofilm formation can only be observed under shaking conditions and are decreased in the Δ phz mutant compared to wild-type cultures, indicating that phenazines are crucial for the formation of biofilms if oxygen as an electron acceptor is unavailable. Furthermore, while the model archaeon Haloferax volcanii does not require archaella for surface attachment under static conditions, we demonstrate that H. volcanii mutants that lack archaella are impaired in early stages of biofilm formation under shaking conditions.
Importance:
Due to the versatility of the mPAD mount, we anticipate that it will aid the analysis of biofilm formation in a broad range of bacteria and archaea. Thereby, it contributes to answering critical biological questions about the regulatory and structural components of biofilm formation and understanding this process in a wide array of environmental, biotechnological, and medical contexts.
