1
|
Feng Y, Arsenault D, Louyakis AS, Altman-Price N, Gophna U, Papke RT, Gogarten JP. Using the pan-genomic framework for the discovery of genomic islands in the haloarchaeon Halorubrum ezzemoulense. mBio 2024; 15:e0040824. [PMID: 38619241 PMCID: PMC11078007 DOI: 10.1128/mbio.00408-24] [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: 03/04/2024] [Accepted: 03/19/2024] [Indexed: 04/16/2024] Open
Abstract
In this study, we use pan-genomics to characterize the genomic variability of the widely dispersed halophilic archaeal species Halorubrum ezzemoulense (Hez). We include a multi-regional sampling of newly sequenced, high-quality draft genomes. The pan-genome graph of the species reveals 50 genomic islands that represent rare accessory genetic capabilities available to members. Most notably, we observe rearrangements that have led to the insertion/recombination/replacement of mutually exclusive genomic islands in equivalent genome positions ("homeocassettes"). These conflicting islands encode for similar functions, but homologs from islands located between the same core genes exhibit high divergence on the amino acid level, while the neighboring core genes are nearly identical. Both islands of a homeocassette often coexist in the same geographic location, suggesting that either island may be beyond the reach of selective sweeps and that these loci of divergence between Hez members are maintained and persist long term. This implies that subsections of the population have different niche preferences and rare metabolic capabilities. After an evaluation of the gene content in the homeocassettes, we speculate that these islands may play a role in the speciation, niche adaptability, and group selection dynamics in Hez. Though homeocassettes are first described in this study, similar replacements and divergence of genes on genomic islands have been previously reported in other Haloarchaea and distantly related Archaea, suggesting that homeocassettes may be a feature in a wide range of organisms outside of Hez.IMPORTANCEThis study catalogs the rare genes discovered in strains of the species Halorubrum ezzemoulense (Hez), an obligate halophilic archaeon, through the perspective of its pan-genome. These rare genes are often found to be arranged on islands that confer metabolic and transport functions and contain genes that have eluded previous studies. The discovery of divergent, but homologous islands occupying equivalent genome positions ("homeocassettes") in different genomes, reveals significant new information on genome evolution in Hez. Homeocassette pairs encode for similar functions, but their dissimilarity and distribution imply high rates of recombination, different specializations, and niche preferences in Hez. The coexistence of both islands of a homeocassette pair in multiple environments demonstrates that both islands are beyond the reach of selective sweeps and that these genome content differences between strains persist long term. The switch between islands through recombination under different environmental conditions may lead to a greater range of niche adaptability in Hez.
Collapse
Affiliation(s)
- Yutian Feng
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Danielle Arsenault
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Artemis S. Louyakis
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Neta Altman-Price
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
- Avinoam Adam Department of Natural Sciences, The Open University of Israel, Raanana, Israel
| | - Uri Gophna
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - R. Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, USA
| |
Collapse
|
2
|
Baláž A, Kajsik M, Budiš J, Szemes T, Turňa J. PHERI-Phage Host ExploRation Pipeline. Microorganisms 2023; 11:1398. [PMID: 37374901 DOI: 10.3390/microorganisms11061398] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
Antibiotic resistance is becoming a common problem in medicine, food, and industry, with multidrug-resistant bacterial strains occurring in all regions. One of the possible future solutions is the use of bacteriophages. Phages are the most abundant form of life in the biosphere, so we can highly likely purify a specific phage against each target bacterium. The identification and consistent characterization of individual phages was a common form of phage work and included determining bacteriophages' host-specificity. With the advent of new modern sequencing methods, there was a problem with the detailed characterization of phages in the environment identified by metagenome analysis. The solution to this problem may be to use a bioinformatic approach in the form of prediction software capable of determining a bacterial host based on the phage whole-genome sequence. The result of our research is the machine learning algorithm-based tool called PHERI. PHERI predicts the suitable bacterial host genus for the purification of individual viruses from different samples. In addition, it can identify and highlight protein sequences that are important for host selection.
Collapse
Affiliation(s)
- Andrej Baláž
- Geneton Ltd., Ilkovicova 8, 841 04 Bratislava, Slovakia
- Department of Applied Informatics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, 842 48 Bratislava, Slovakia
| | - Michal Kajsik
- Science Park, Comenius University, Ilkovicova 8, 841 04 Bratislava, Slovakia
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 841 04 Bratislava, Slovakia
- Medirex Group Academy n.o., Novozamocka 1, 949 05 Nitra, Slovakia
| | - Jaroslav Budiš
- Geneton Ltd., Ilkovicova 8, 841 04 Bratislava, Slovakia
- Science Park, Comenius University, Ilkovicova 8, 841 04 Bratislava, Slovakia
- Slovak Centre of Scientific and Technical Information (SCSTI), Lamacska Cesta 8/A, 811 04 Bratislava, Slovakia
| | - Tomáš Szemes
- Geneton Ltd., Ilkovicova 8, 841 04 Bratislava, Slovakia
- Science Park, Comenius University, Ilkovicova 8, 841 04 Bratislava, Slovakia
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 841 04 Bratislava, Slovakia
| | - Ján Turňa
- Science Park, Comenius University, Ilkovicova 8, 841 04 Bratislava, Slovakia
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 841 04 Bratislava, Slovakia
| |
Collapse
|
3
|
Amgarten D, Iha BKV, Piroupo CM, da Silva AM, Setubal JC. vHULK, a New Tool for Bacteriophage Host Prediction Based on Annotated Genomic Features and Neural Networks. PHAGE (NEW ROCHELLE, N.Y.) 2022; 3:204-212. [PMID: 36793881 PMCID: PMC9917316 DOI: 10.1089/phage.2021.0016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Background The experimental determination of a bacteriophage host is a laborious procedure. Thus, there is a pressing need for reliable computational predictions of bacteriophage hosts. Materials and Methods We developed the program vHULK for phage host prediction based on 9504 phage genome features, which consider alignment significance scores between predicted proteins and a curated database of viral protein families. The features were fed to a neural network, and two models were trained to predict 77 host genera and 118 host species. Results In controlled random test sets with 90% redundancy reduction in terms of protein similarity, vHULK obtained on average 83% precision and 79% recall at the genus level, and 71% precision and 67% recall at the species level. The performance of vHULK was compared against three other tools on a test data set with 2153 phage genomes. On this data set, vHULK achieved better performance at both the genus and the species levels than the other tools. Conclusions Our results suggest that vHULK represents an advance on the state of art in phage host prediction.
Collapse
Affiliation(s)
- Deyvid Amgarten
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | - Carlos Morais Piroupo
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Aline Maria da Silva
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - João Carlos Setubal
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|
4
|
Correa AMS, Howard-Varona C, Coy SR, Buchan A, Sullivan MB, Weitz JS. Revisiting the rules of life for viruses of microorganisms. Nat Rev Microbiol 2021; 19:501-513. [PMID: 33762712 DOI: 10.1038/s41579-021-00530-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2021] [Indexed: 02/01/2023]
Abstract
Viruses that infect microbial hosts have traditionally been studied in laboratory settings with a focus on either obligate lysis or persistent lysogeny. In the environment, these infection archetypes are part of a continuum that spans antagonistic to beneficial modes. In this Review, we advance a framework to accommodate the context-dependent nature of virus-microorganism interactions in ecological communities by synthesizing knowledge from decades of virology research, eco-evolutionary theory and recent technological advances. We discuss that nuanced outcomes, rather than the extremes of the continuum, are particularly likely in natural communities given variability in abiotic factors, the availability of suboptimal hosts and the relevance of multitrophic partnerships. We revisit the 'rules of life' in terms of how long-term infections shape the fate of viruses and microbial cells, populations and ecosystems.
Collapse
Affiliation(s)
| | | | - Samantha R Coy
- BioSciences Department, Rice University, Houston, TX, USA
| | - Alison Buchan
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA.
| | - Matthew B Sullivan
- Department of Microbiology, The Ohio State University, Columbus, OH, USA. .,Department of Civil, Environmental, and Geodetic Engineering, The Ohio State University, Columbus, OH, USA.
| | - Joshua S Weitz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA. .,School of Physics, Georgia Institute of Technology, Atlanta, GA, USA.
| |
Collapse
|
5
|
Pujato S, Galliani V, Irazoqui JM, Amadío A, Quiberoni A, Mercanti D. Analysis of CRISPR systems of types II-A, I-E and I-C in strains of Lacticaseibacillus. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2021.105027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
6
|
Huang D, Yu P, Ye M, Schwarz C, Jiang X, Alvarez PJJ. Enhanced mutualistic symbiosis between soil phages and bacteria with elevated chromium-induced environmental stress. MICROBIOME 2021; 9:150. [PMID: 34183048 PMCID: PMC8240259 DOI: 10.1186/s40168-021-01074-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/07/2021] [Indexed: 05/03/2023]
Abstract
BACKGROUND Microbe-virus interactions have broad implications on the composition, function, and evolution of microbiomes. Elucidating the effects of environmental stresses on these interactions is critical to identify the ecological function of viral communities and understand microbiome environmental adaptation. Heavy metal-contaminated soils represent a relevant ecosystem to study the interplay between microbes, viruses, and environmental stressors. RESULTS Metagenomic analysis revealed that Cr pollution adversely altered the abundance, diversity, and composition of viral and bacterial communities. Host-phage linkage based on CRISPR indicated that, in soils with high Cr contamination, the abundance of phages associated with heavy metal-tolerant hosts increased, as did the relative abundance of phages with broad host ranges (identified as host-phage linkages across genera), which would facilitate transfection and broader distribution of heavy metal resistance genes in the bacterial community. Examining variations along the pollutant gradient, enhanced mutualistic phage-bacterium interactions were observed in the face of greater environmental stresses. Specifically, the fractions of lysogens in bacterial communities (identified by integrase genes within bacterial genomes and prophage induction assay by mitomycin-C) were positively correlated with Cr contamination levels. Furthermore, viral genomic analysis demonstrated that lysogenic phages under higher Cr-induced stresses carried more auxiliary metabolic genes regulating microbial heavy metal detoxification. CONCLUSION With the intensification of Cr-induced environmental stresses, the composition, replication strategy, and ecological function of the phage community all evolve alongside the bacterial community to adapt to extreme habitats. These result in a transformation of the phage-bacterium interaction from parasitism to mutualism in extreme environments and underscore the influential role of phages in bacterial adaptation to pollution-related stress and in related biogeochemical processes. Video Abstract.
Collapse
Affiliation(s)
- Dan Huang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Pingfeng Yu
- Department of Civil and Environmental Engineering, Rice University, Houston, 77005, USA.
| | - Mao Ye
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, People's Republic of China.
| | - Cory Schwarz
- Department of Civil and Environmental Engineering, Rice University, Houston, 77005, USA
| | - Xin Jiang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, People's Republic of China
| | - Pedro J J Alvarez
- Department of Civil and Environmental Engineering, Rice University, Houston, 77005, USA
| |
Collapse
|
7
|
Prokaryotic and eukaryotic diversity in hydrothermal continental systems. Arch Microbiol 2021; 203:3751-3766. [PMID: 34143270 DOI: 10.1007/s00203-021-02416-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 02/07/2023]
Abstract
The term extremophile was suggested more than 30 years ago and represents microorganisms that are capable of developing and living under extreme conditions, these conditions being particularly hostile to other types of microorganisms and to humankind. In terrestrial hydrothermal sites, like hot springs, "mud pools", solfataras, and geysers, the dominant extreme conditions are high temperature, low or high pH, and high levels of salinity. The diversity of microorganisms inhabiting these sites is determined by the conditions of the environment. Organisms belonging to the domains Archaea and Bacteria are more represented than the one belonging to Eukarya. Eukarya members tend to be less present because of their lower tolerance to higher temperatures, however, they perform important ecosystem processes when present. Both prokaryotes and eukaryotes have morphological and physical adaptations that allow them to colonize extreme environments. Microbial mats are complex associations of microorganisms that help the colonization of more extreme systems. In this review, a characterization of prokaryotic and eukaryotic organisms that populate terrestrial hydrothermal systems are made.
Collapse
|
8
|
Glickman C, Hendrix J, Strong M. Simulation study and comparative evaluation of viral contiguous sequence identification tools. BMC Bioinformatics 2021; 22:329. [PMID: 34130621 PMCID: PMC8207588 DOI: 10.1186/s12859-021-04242-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 06/04/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Viruses, including bacteriophages, are important components of environmental and human associated microbial communities. Viruses can act as extracellular reservoirs of bacterial genes, can mediate microbiome dynamics, and can influence the virulence of clinical pathogens. Various targeted metagenomic analysis techniques detect viral sequences, but these methods often exclude large and genome integrated viruses. In this study, we evaluate and compare the ability of nine state-of-the-art bioinformatic tools, including Vibrant, VirSorter, VirSorter2, VirFinder, DeepVirFinder, MetaPhinder, Kraken 2, Phybrid, and a BLAST search using identified proteins from the Earth Virome Pipeline to identify viral contiguous sequences (contigs) across simulated metagenomes with different read distributions, taxonomic compositions, and complexities. RESULTS Of the tools tested in this study, VirSorter achieved the best F1 score while Vibrant had the highest average F1 score at predicting integrated prophages. Though less balanced in its precision and recall, Kraken2 had the highest average precision by a substantial margin. We introduced the machine learning tool, Phybrid, which demonstrated an improvement in average F1 score over tools such as MetaPhinder. The tool utilizes machine learning with both gene content and nucleotide features. The addition of nucleotide features improves the precision and recall compared to the gene content features alone.Viral identification by all tools was not impacted by underlying read distribution but did improve with contig length. Tool performance was inversely related to taxonomic complexity and varied by the phage host. For instance, Rhizobium and Enterococcus phages were identified consistently by the tools; whereas, Neisseria prophage sequences were commonly missed in this study. CONCLUSION This study benchmarked the performance of nine state-of-the-art bioinformatic tools to identify viral contigs across different simulation conditions. This study explored the ability of the tools to identify integrated prophage elements traditionally excluded from targeted sequencing approaches. Our comprehensive analysis of viral identification tools to assess their performance in a variety of situations provides valuable insights to viral researchers looking to mine viral elements from publicly available metagenomic data.
Collapse
Affiliation(s)
- Cody Glickman
- Center for Genes, Environment, and Health, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206, USA.
- Computational Bioscience, University of Colorado Anschutz, 12801 E 17th Avenue, Aurora, CO, 80045, USA.
| | - Jo Hendrix
- Center for Genes, Environment, and Health, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206, USA
- Computational Bioscience, University of Colorado Anschutz, 12801 E 17th Avenue, Aurora, CO, 80045, USA
| | - Michael Strong
- Center for Genes, Environment, and Health, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206, USA
- Computational Bioscience, University of Colorado Anschutz, 12801 E 17th Avenue, Aurora, CO, 80045, USA
| |
Collapse
|
9
|
Najjari A, Stathopoulou P, Elmnasri K, Hasnaoui F, Zidi I, Sghaier H, Ouzari HI, Cherif A, Tsiamis G. Assessment of 16S rRNA Gene-Based Phylogenetic Diversity of Archaeal Communities in Halite-Crystal Salts Processed from Natural Saharan Saline Systems of Southern Tunisia. BIOLOGY 2021; 10:biology10050397. [PMID: 34064384 PMCID: PMC8147861 DOI: 10.3390/biology10050397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 12/27/2022]
Abstract
A thorough assessment of the phylogenetic diversity and community structure of halophilic archaea from three halite-crystal salts, processed from two separated saline systems of Southern Tunisia has been performed using culture dependent and independent methods targeting different regions of 16S rRNA gene sequences including DGGE, 16S rRNA clone libraries and Illumina Miseq sequencing. Two samples, CDR (red halite-crystal salts) and CDW (white halite-crystal salts), were collected from Chott-Eljerid and one sample CDZ (white halite-crystal salts) from Chott Douz. Fourteen isolates were identified as Halorubrum, Haloferax, Haloarcula, and Halogeometricum genera members. Culture-independent approach revealed a high diversity of archaeal members present in all samples, represented by the Euryarchaeal phylum and the dominance of the Halobacteria class. Nanohaloarchaea were also identified only in white halite samples based on metagenomic analysis. In fact, a total of 61 genera were identified with members of the Halorhabdus, Halonotius, Halorubrum, Haloarcula, and unclassified. Halobacteriaceae were shared among all samples. Unexpected diversity profiles between samples was observed where the red halite crust sample was considered as the most diverse one. The highest diversity was observed with Miseq approach, nevertheless, some genera were detected only with 16S rRNA clone libraries and cultured approaches.
Collapse
Affiliation(s)
- Afef Najjari
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092 Tunis, Tunisia; (F.H.); (I.Z.); (H.I.O.)
- Correspondence:
| | - Panagiota Stathopoulou
- Department of Environmental Engineering, Laboratory of Systems Microbiology and Applied Genomics, University of Patras, 2 Seferi Str., 30100 Agrinio, Greece; (P.S.); (G.T.)
| | - Khaled Elmnasri
- Higher Institute for Biotechnology, University Manouba, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 Ariana, Tunisia; (K.E.); (H.S.); (A.C.)
| | - Faten Hasnaoui
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092 Tunis, Tunisia; (F.H.); (I.Z.); (H.I.O.)
| | - Ines Zidi
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092 Tunis, Tunisia; (F.H.); (I.Z.); (H.I.O.)
| | - Haitham Sghaier
- Higher Institute for Biotechnology, University Manouba, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 Ariana, Tunisia; (K.E.); (H.S.); (A.C.)
- Laboratory “Energy and Matter for Development of Nuclear Sciences” (LR16CNSTN02), National Center for Nuclear Sciences and Technology (CNSTN), 2020 Sidi Thabet, Tunisia
| | - Hadda Imene Ouzari
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092 Tunis, Tunisia; (F.H.); (I.Z.); (H.I.O.)
| | - Ameur Cherif
- Higher Institute for Biotechnology, University Manouba, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 Ariana, Tunisia; (K.E.); (H.S.); (A.C.)
| | - George Tsiamis
- Department of Environmental Engineering, Laboratory of Systems Microbiology and Applied Genomics, University of Patras, 2 Seferi Str., 30100 Agrinio, Greece; (P.S.); (G.T.)
| |
Collapse
|
10
|
Aldeguer-Riquelme B, Ramos-Barbero MD, Santos F, Antón J. Environmental dissolved DNA harbours meaningful biological information on microbial community structure. Environ Microbiol 2021; 23:2669-2682. [PMID: 33817941 DOI: 10.1111/1462-2920.15510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 04/03/2021] [Indexed: 01/21/2023]
Abstract
Extracellular DNA (eDNA) comprises all the DNA molecules outside cells. This component of microbial ecosystems may serve as a source of nutrients and genetic information. Hypersaline environments harbour one of the highest concentrations of eDNA reported for natural systems, which has been attributed to the physicochemical preservative effect of salts and to high viral abundance. Here, we compared centrifugation and filtration protocols for the extraction of dissolved DNA (dDNA, as opposed to eDNA that also includes DNA from free viral particles) from a solar saltern crystallizer pond (CR30) water sample. The crystallizer dDNA fraction has been characterized, for the first time, and compared with cellular and viral metagenomes from the same location. High-speed centrifugation affected CR30 dDNA concentration and composition due to cell lysis, highlighting that protocol optimization should be the first step in dDNA studies. Crystallizer dDNA, which accounted for lower concentrations than those previously reported for hypersaline anoxic sediments, had a mixed viral and cellular origin, was enriched in archaeal DNA and had a distinctive taxonomic composition compared to that from the cellular assemblage of the same sample. Bioinformatic analyses indicated that nanohaloarchaeal viruses could be a cause for these differences.
Collapse
Affiliation(s)
- Borja Aldeguer-Riquelme
- Department of Physiology, Genetics, and Microbiology, University of Alicante, Alicante, 03080, Spain
| | | | - Fernando Santos
- Department of Physiology, Genetics, and Microbiology, University of Alicante, Alicante, 03080, Spain
| | - Josefa Antón
- Department of Physiology, Genetics, and Microbiology, University of Alicante, Alicante, 03080, Spain.,Multidisciplinary Institute of Environmental Studies Ramón Margalef, University of Alicante, Alicante, 03080, Spain
| |
Collapse
|
11
|
Abstract
Viruses are extremely diverse and modulate important biological and ecological processes globally. However, much of viral diversity remains uncultured and yet to be discovered. Several powerful culture-independent tools, in particular metagenomics, have substantially advanced virus discovery. Among those tools is single-virus genomics, which yields sequenced reference genomes from individual sorted virus particles without the need for cultivation. This new method complements virus culturing and metagenomic approaches and its advantages include targeted investigation of specific virus groups and investigation of genomic microdiversity within viral populations. In this Review, we provide a brief history of single-virus genomics, outline how this emergent method has facilitated advances in virus ecology and discuss its current limitations and future potential. Finally, we address how this method may synergistically intersect with other single-virus and single-cell approaches.
Collapse
|
12
|
Kumar S, Paul D, Bhushan B, Wakchaure GC, Meena KK, Shouche Y. Traversing the "Omic" landscape of microbial halotolerance for key molecular processes and new insights. Crit Rev Microbiol 2020; 46:631-653. [PMID: 32991226 DOI: 10.1080/1040841x.2020.1819770] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Post-2005, the biology of the salt afflicted habitats is predominantly studied employing high throughput "Omic" approaches comprising metagenomics, transcriptomics, metatranscriptomics, metabolomics, and proteomics. Such "Omic-based" studies have deciphered the unfamiliar details about microbial salt-stress biology. The MAGs (Metagenome-assembled genomes) of uncultured halophilic microbial lineages such as Nanohaloarchaea and haloalkaliphilic members within CPR (Candidate Phyla Radiation) have been reconstructed from diverse hypersaline habitats. The study of MAGs of such uncultured halophilic microbial lineages has unveiled the genomic basis of salt stress tolerance in "yet to culture" microbial lineages. Furthermore, functional metagenomic approaches have been used to decipher the novel genes from uncultured microbes and their possible role in microbial salt-stress tolerance. The present review focuses on the new insights into microbial salt-stress biology gained through different "Omic" approaches. This review also summarizes the key molecular processes that underlie microbial salt-stress response, and their role in microbial salt-stress tolerance has been confirmed at more than one "Omic" levels.
Collapse
Affiliation(s)
- Satish Kumar
- National Centre for Microbial Resource, National Centre for Cell Science, Pune, India.,ICAR-National Institute of Abiotic Stress Management, Baramati, Pune, India
| | - Dhiraj Paul
- National Centre for Microbial Resource, National Centre for Cell Science, Pune, India
| | - Bharat Bhushan
- ICAR-National Bureau of Plant Genetic Resources, New Delhi, India
| | - G C Wakchaure
- ICAR-National Institute of Abiotic Stress Management, Baramati, Pune, India
| | - Kamlesh K Meena
- ICAR-National Institute of Abiotic Stress Management, Baramati, Pune, India
| | - Yogesh Shouche
- National Centre for Microbial Resource, National Centre for Cell Science, Pune, India
| |
Collapse
|
13
|
An Uncultivated Virus Infecting a Nanoarchaeal Parasite in the Hot Springs of Yellowstone National Park. J Virol 2020; 94:JVI.01213-19. [PMID: 31666377 DOI: 10.1128/jvi.01213-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/10/2019] [Indexed: 12/20/2022] Open
Abstract
The Nanoarchaeota are small cells with reduced genomes that are found attached to and dependent on a second archaeal cell for their growth and replication. Initially found in marine hydrothermal environments and subsequently in terrestrial geothermal hot springs, the Nanoarchaeota species that have been described are obligate ectobionts, each with a different host species. However, no viruses had been described that infect the Nanoarchaeota. Here, we identify a virus infecting Nanoarchaeota by the use of a combination of viral metagenomic and bioinformatic approaches. This virus, tentatively named Nanoarchaeota Virus 1 (NAV1), consists of a 35.6-kb circular DNA genome coding for 52 proteins. We further demonstrate that this virus is broadly distributed among Yellowstone National Park hot springs. NAV1 is one of the first examples of a virus infecting a single-celled organism that is itself an ectobiont of another single-celled organism.IMPORTANCE Here, we present evidence of the first virus found to infect Nanoarchaeota, a symbiotic archaean found in acidic hot springs of Yellowstone National Park, USA. Using culture-independent techniques, we provide the genome sequence and identify the archaeal host species of a novel virus, NAV1. NAV1 is the first example of a virus infecting an archaeal species that is itself an obligate symbiont and dependent on a second host organism for growth and cellular replication. On the basis of annotation of the NAV1 genome, we propose that this virus is the founding member of a new viral family, further demonstrating the remarkable genetic diversity of archaeal viruses.
Collapse
|
14
|
Ramos‐Barbero MD, Martínez JM, Almansa C, Rodríguez N, Villamor J, Gomariz M, Escudero C, Rubin SDC, Antón J, Martínez‐García M, Amils R. Prokaryotic and viral community structure in the singular chaotropic salt lake Salar de Uyuni. Environ Microbiol 2019; 21:2029-2042. [DOI: 10.1111/1462-2920.14549] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 01/19/2019] [Accepted: 01/29/2019] [Indexed: 02/01/2023]
Affiliation(s)
| | - José M. Martínez
- Department of Virology and Microbiology, Centro de Biología Molecular Severo OchoaUniversidad Autónoma de Madrid (CBMSO, CSIC‐UAM) Cantoblanco, 28049 Madrid Spain
| | - Cristina Almansa
- Department of Physiology, Genetics and MicrobiologyUniversidad de Alicante Alicante Spain
| | - Nuria Rodríguez
- Department of Planetology and HabitabilityCentro de Astrobiología (CAB, INTA‐CSIC) 28055 Torrejón de Ardoz Spain
| | - Judith Villamor
- Department of Physiology, Genetics and MicrobiologyUniversidad de Alicante Alicante Spain
| | - María Gomariz
- Department of Physiology, Genetics and MicrobiologyUniversidad de Alicante Alicante Spain
| | - Cristina Escudero
- Department of Virology and Microbiology, Centro de Biología Molecular Severo OchoaUniversidad Autónoma de Madrid (CBMSO, CSIC‐UAM) Cantoblanco, 28049 Madrid Spain
| | - Sergio dC Rubin
- Department of Virology and Microbiology, Centro de Biología Molecular Severo OchoaUniversidad Autónoma de Madrid (CBMSO, CSIC‐UAM) Cantoblanco, 28049 Madrid Spain
- Université catholique de LouvainEarth and Life Institute, Georges Lemaître Centre for Earth and Climate Research Belgium
| | - Josefa Antón
- Department of Physiology, Genetics and MicrobiologyUniversidad de Alicante Alicante Spain
| | - Manuel Martínez‐García
- Department of Physiology, Genetics and MicrobiologyUniversidad de Alicante Alicante Spain
| | - Ricardo Amils
- Department of Virology and Microbiology, Centro de Biología Molecular Severo OchoaUniversidad Autónoma de Madrid (CBMSO, CSIC‐UAM) Cantoblanco, 28049 Madrid Spain
- Department of Planetology and HabitabilityCentro de Astrobiología (CAB, INTA‐CSIC) 28055 Torrejón de Ardoz Spain
| |
Collapse
|
15
|
Roux S, Brum JR. A viral reckoning: viruses emerge as essential manipulators of global ecosystems. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:3-8. [PMID: 30298570 DOI: 10.1111/1758-2229.12700] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 09/30/2018] [Indexed: 06/08/2023]
Affiliation(s)
- Simon Roux
- US DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Walnut Creek, CA, 94598, USA
| | - Jennifer R Brum
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70808, USA
| |
Collapse
|
16
|
Dombrowski N, Lee JH, Williams TA, Offre P, Spang A. Genomic diversity, lifestyles and evolutionary origins of DPANN archaea. FEMS Microbiol Lett 2019; 366:5281434. [PMID: 30629179 PMCID: PMC6349945 DOI: 10.1093/femsle/fnz008] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/07/2019] [Indexed: 12/16/2022] Open
Abstract
Archaea-a primary domain of life besides Bacteria-have for a long time been regarded as peculiar organisms that play marginal roles in biogeochemical cycles. However, this picture changed with the discovery of a large diversity of archaea in non-extreme environments enabled by the use of cultivation-independent methods. These approaches have allowed the reconstruction of genomes of uncultivated microorganisms and revealed that archaea are diverse and broadly distributed in the biosphere and seemingly include a large diversity of putative symbiotic organisms, most of which belong to the tentative archaeal superphylum referred to as DPANN. This archaeal group encompasses at least 10 different lineages and includes organisms with extremely small cell and genome sizes and limited metabolic capabilities. Therefore, many members of DPANN may be obligately dependent on symbiotic interactions with other organisms and may even include novel parasites. In this contribution, we review the current knowledge of the gene repertoires and lifestyles of members of this group and discuss their placement in the tree of life, which is the basis for our understanding of the deep microbial roots and the role of symbiosis in the evolution of life on Earth.
Collapse
Affiliation(s)
- Nina Dombrowski
- NIOZ, Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, P.O. Box 59, NL-1790 AB Den Burg, The Netherlands
- Department of Marine Science, University of Texas at Austin, Marine Science Institute, 750 Channel View Drive, Port Aransas, TX 78373, USA
| | - Jun-Hoe Lee
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, P.O. Box 596, Husargatan 3, SE-75123 Uppsala, Sweden
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, Bristol BS8 1TQ, UK
| | - Pierre Offre
- NIOZ, Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, P.O. Box 59, NL-1790 AB Den Burg, The Netherlands
| | - Anja Spang
- NIOZ, Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, P.O. Box 59, NL-1790 AB Den Burg, The Netherlands
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, P.O. Box 596, Husargatan 3, SE-75123 Uppsala, Sweden
| |
Collapse
|
17
|
González-Torres P, Gabaldón T. Genome Variation in the Model Halophilic Bacterium Salinibacter ruber. Front Microbiol 2018; 9:1499. [PMID: 30072959 PMCID: PMC6060240 DOI: 10.3389/fmicb.2018.01499] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/18/2018] [Indexed: 01/08/2023] Open
Abstract
The halophilic bacterium Salinibacter ruber is an abundant and ecologically important member of halophilic communities worldwide. Given its broad distribution and high intraspecific genetic diversity, S. ruber is considered one of the main models for ecological and evolutionary studies of bacterial adaptation to hypersaline environments. However, current insights on the genomic diversity of this species is limited to the comparison of the genomes of two co-isolated strains. Here, we present a comparative genomic analysis of eight S. ruber strains isolated at two different time points in each of two different Mediterranean solar salterns. Our results show an open pangenome with contrasting evolutionary patterns in the core and accessory genomes. We found that the core genome is shaped by extensive homologous recombination (HR), which results in limited sequence variation within population clusters. In contrast, the accessory genome is modulated by horizontal gene transfer (HGT), with genomic islands and plasmids acting as gateways to the rest of the genome. In addition, both types of genetic exchange are modulated by restriction and modification (RM) or CRISPR-Cas systems. Finally, genes differentially impacted by such processes reveal functional processes potentially relevant for environmental interactions and adaptation to extremophilic conditions. Altogether, our results support scenarios that conciliate “Neutral” and “Constant Diversity” models of bacterial evolution.
Collapse
Affiliation(s)
- Pedro González-Torres
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain.,Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona, Spain
| | - Toni Gabaldón
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona, Spain.,Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| |
Collapse
|
18
|
Breitbart M, Bonnain C, Malki K, Sawaya NA. Phage puppet masters of the marine microbial realm. Nat Microbiol 2018; 3:754-766. [PMID: 29867096 DOI: 10.1038/s41564-018-0166-y] [Citation(s) in RCA: 321] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 04/20/2018] [Indexed: 11/09/2022]
Abstract
Viruses numerically dominate our oceans; however, we have only just begun to document the diversity, host range and infection dynamics of marine viruses, as well as the subsequent effects of infection on both host cell metabolism and oceanic biogeochemistry. Bacteriophages (that is, phages: viruses that infect bacteria) are highly abundant and are known to play critical roles in bacterial mortality, biogeochemical cycling and horizontal gene transfer. This Review Article summarizes current knowledge of marine viral ecology and highlights the importance of phage particles to the dissolved organic matter pool, as well as the complex interactions between phages and their bacterial hosts. We emphasize the newly recognized roles of phages as puppet masters of their bacterial hosts, where phages are capable of altering the metabolism of infected bacteria through the expression of auxiliary metabolic genes and the redirection of host gene expression patterns. Finally, we propose the 'royal family model' as a hypothesis to describe successional patterns of bacteria and phages over time in marine systems, where despite high richness and significant seasonal differences, only a small number of phages appear to continually dominate a given marine ecosystem. Although further testing is required, this model provides a framework for assessing the specificity and ecological consequences of phage-host dynamics.
Collapse
Affiliation(s)
- Mya Breitbart
- College of Marine Science, University of South Florida, Saint Petersburg, FL, USA.
| | - Chelsea Bonnain
- College of Marine Science, University of South Florida, Saint Petersburg, FL, USA
| | - Kema Malki
- College of Marine Science, University of South Florida, Saint Petersburg, FL, USA
| | - Natalie A Sawaya
- College of Marine Science, University of South Florida, Saint Petersburg, FL, USA
| |
Collapse
|
19
|
Xu Y, Zhao F. Single-cell metagenomics: challenges and applications. Protein Cell 2018; 9:501-510. [PMID: 29696589 PMCID: PMC5960468 DOI: 10.1007/s13238-018-0544-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 04/18/2018] [Indexed: 02/01/2023] Open
Abstract
With the development of high throughput sequencing and single-cell genomics technologies, many uncultured bacterial communities have been dissected by combining these two techniques. Especially, by simultaneously leveraging of single-cell genomics and metagenomics, researchers can greatly improve the efficiency and accuracy of obtaining whole genome information from complex microbial communities, which not only allow us to identify microbes but also link function to species, identify subspecies variations, study host-virus interactions and etc. Here, we review recent developments and the challenges need to be addressed in single-cell metagenomics, including potential contamination, uneven sequence coverage, sequence chimera, genome assembly and annotation. With the development of sequencing and computational methods, single-cell metagenomics will undoubtedly broaden its application in various microbiome studies.
Collapse
Affiliation(s)
- Yuan Xu
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China
| | - Fangqing Zhao
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
20
|
Vera-Gargallo B, Ventosa A. Metagenomic Insights into the Phylogenetic and Metabolic Diversity of the Prokaryotic Community Dwelling in Hypersaline Soils from the Odiel Saltmarshes (SW Spain). Genes (Basel) 2018. [PMID: 29518047 PMCID: PMC5867873 DOI: 10.3390/genes9030152] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hypersaline environments encompass aquatic and terrestrial habitats. While only a limited number of studies on the microbial diversity of saline soils have been carried out, hypersaline lakes and marine salterns have been thoroughly investigated, resulting in an aquatic-biased knowledge about life in hypersaline environments. To improve our understanding of the assemblage of microbes thriving in saline soils, we assessed the phylogenetic diversity and metabolic potential of the prokaryotic community of two hypersaline soils (with electrical conductivities of ~24 and 55 dS/m) from the Odiel saltmarshes (Spain) by metagenomics. Comparative analysis of these soil databases with available datasets from salterns ponds allowed further identification of unique and shared traits of microbial communities dwelling in these habitats. Saline soils harbored a more diverse prokaryotic community and, in contrast to their aquatic counterparts, contained sequences related to both known halophiles and groups without known halophilic or halotolerant representatives, which reflects the physical heterogeneity of the soil matrix. Our results suggest that Haloquadratum and certain Balneolaeota members may preferentially thrive in aquatic or terrestrial habitats, respectively, while haloarchaea, nanohaloarchaea and Salinibacter may be similarly adapted to both environments. We reconstructed 4 draft genomes related to Bacteroidetes, Balneolaeota and Halobacteria and appraised their metabolism, osmoadaptation strategies and ecology. This study greatly improves the current understanding of saline soils microbiota.
Collapse
Affiliation(s)
- Blanca Vera-Gargallo
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain.
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain.
| |
Collapse
|
21
|
Archaeal Viruses from High-Temperature Environments. Genes (Basel) 2018; 9:genes9030128. [PMID: 29495485 PMCID: PMC5867849 DOI: 10.3390/genes9030128] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/19/2018] [Accepted: 02/21/2018] [Indexed: 12/21/2022] Open
Abstract
Archaeal viruses are some of the most enigmatic viruses known, due to the small number that have been characterized to date. The number of known archaeal viruses lags behind known bacteriophages by over an order of magnitude. Despite this, the high levels of genetic and morphological diversity that archaeal viruses display has attracted researchers for over 45 years. Extreme natural environments, such as acidic hot springs, are almost exclusively populated by Archaea and their viruses, making these attractive environments for the discovery and characterization of new viruses. The archaeal viruses from these environments have provided insights into archaeal biology, gene function, and viral evolution. This review focuses on advances from over four decades of archaeal virology, with a particular focus on archaeal viruses from high temperature environments, the existing challenges in understanding archaeal virus gene function, and approaches being taken to overcome these limitations.
Collapse
|
22
|
Krupovic M, Cvirkaite-Krupovic V, Iranzo J, Prangishvili D, Koonin EV. Viruses of archaea: Structural, functional, environmental and evolutionary genomics. Virus Res 2017; 244:181-193. [PMID: 29175107 DOI: 10.1016/j.virusres.2017.11.025] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 11/18/2022]
Abstract
Viruses of archaea represent one of the most enigmatic parts of the virosphere. Most of the characterized archaeal viruses infect extremophilic hosts and display remarkable diversity of virion morphotypes, many of which have never been observed among viruses of bacteria or eukaryotes. The uniqueness of the virion morphologies is matched by the distinctiveness of the genomes of these viruses, with ∼75% of genes encoding unique proteins, refractory to functional annotation based on sequence analyses. In this review, we summarize the state-of-the-art knowledge on various aspects of archaeal virus genomics. First, we outline how structural and functional genomics efforts provided valuable insights into the functions of viral proteins and revealed intricate details of the archaeal virus-host interactions. We then highlight recent metagenomics studies, which provided a glimpse at the diversity of uncultivated viruses associated with the ubiquitous archaea in the oceans, including Thaumarchaeota, Marine Group II Euryarchaeota, and others. These findings, combined with the recent discovery that archaeal viruses mediate a rapid turnover of thaumarchaea in the deep sea ecosystems, illuminate the prominent role of these viruses in the biosphere. Finally, we discuss the origins and evolution of archaeal viruses and emphasize the evolutionary relationships between viruses and non-viral mobile genetic elements. Further exploration of the archaeal virus diversity as well as functional studies on diverse virus-host systems are bound to uncover novel, unexpected facets of the archaeal virome.
Collapse
Affiliation(s)
- Mart Krupovic
- Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, Paris, France.
| | | | - Jaime Iranzo
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, USA
| | - David Prangishvili
- Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, Paris, France
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, USA
| |
Collapse
|
23
|
Abstract
One of the most prominent features of archaea is the extraordinary diversity of their DNA viruses. Many archaeal viruses differ substantially in morphology from bacterial and eukaryotic viruses and represent unique virus families. The distinct nature of archaeal viruses also extends to the gene composition and architectures of their genomes and the properties of the proteins that they encode. Environmental research has revealed prominent roles of archaeal viruses in influencing microbial communities in ocean ecosystems, and recent metagenomic studies have uncovered new groups of archaeal viruses that infect extremophiles and mesophiles in diverse habitats. In this Review, we summarize recent advances in our understanding of the genomic and morphological diversity of archaeal viruses and the molecular biology of their life cycles and virus-host interactions, including interactions with archaeal CRISPR-Cas systems. We also examine the potential origins and evolution of archaeal viruses and discuss their place in the global virosphere.
Collapse
|
24
|
Characterization of ecologically diverse viruses infecting co-occurring strains of cosmopolitan hyperhalophilic Bacteroidetes. ISME JOURNAL 2017; 12:424-437. [PMID: 29099492 PMCID: PMC5776456 DOI: 10.1038/ismej.2017.175] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/16/2017] [Accepted: 08/23/2017] [Indexed: 12/12/2022]
Abstract
Hypersaline environments close to saturation harbor the highest density of virus-like particles reported for aquatic systems as well as low microbial diversity. Thus, they offer unique settings for studying virus–host interactions in nature. However, no viruses have been isolated so far infecting the two most abundant inhabitants of these systems (that is, the euryarchaeon Haloquadratum walsbyi and the bacteroidetes Salinibacter ruber). Here, using three different co-occurring strains, we have isolated eight viruses infecting the ubiquitous S. ruber that constitute three new different genera (named as ‘Holosalinivirus’, ‘Kryptosalinivirus’ and ‘Kairosalinivirus’) according to their genomic traits, different host range, virus–host interaction capabilities and abundances in natural systems worldwide. Furthermore, to get a more complete and comprehensive view of S. ruber virus assemblages in nature, a microcosm experiment was set with a mixture of S. ruber strains challenged with a brine virus concentrate, and changes of viral populations were monitored by viral metagenomics. Only viruses closely related to kairosalinivirus (strictly lytic and wide host range) were enriched, despite their low initial abundance in the natural sample. Metagenomic analyses of the mesocosms allowed the complete recovery of kairosalinivirus genomes using an ad hoc assembly strategy as common viral metagenomic assembly tools failed despite their abundance, which underlines the limitations of current approaches. The increase of this type of viruses was accompanied by an increase in the diversity of the group, as shown by contig recruitment. These results are consistent with a scenario in which host range, not only virus and host abundances, is a key factor in determining virus fate in nature.
Collapse
|
25
|
Roux S, Emerson JB, Eloe-Fadrosh EA, Sullivan MB. Benchmarking viromics: an in silico evaluation of metagenome-enabled estimates of viral community composition and diversity. PeerJ 2017; 5:e3817. [PMID: 28948103 PMCID: PMC5610896 DOI: 10.7717/peerj.3817] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 08/26/2017] [Indexed: 12/20/2022] Open
Abstract
Background Viral metagenomics (viromics) is increasingly used to obtain uncultivated viral genomes, evaluate community diversity, and assess ecological hypotheses. While viromic experimental methods are relatively mature and widely accepted by the research community, robust bioinformatics standards remain to be established. Here we used in silico mock viral communities to evaluate the viromic sequence-to-ecological-inference pipeline, including (i) read pre-processing and metagenome assembly, (ii) thresholds applied to estimate viral relative abundances based on read mapping to assembled contigs, and (iii) normalization methods applied to the matrix of viral relative abundances for alpha and beta diversity estimates. Results Tools specifically designed for metagenomes, specifically metaSPAdes, MEGAHIT, and IDBA-UD, were the most effective at assembling viromes. Read pre-processing, such as partitioning, had virtually no impact on assembly output, but may be useful when hardware is limited. Viral populations with 2–5 × coverage typically assembled well, whereas lesser coverage led to fragmented assembly. Strain heterogeneity within populations hampered assembly, especially when strains were closely related (average nucleotide identity, or ANI ≥97%) and when the most abundant strain represented <50% of the population. Viral community composition assessments based on read recruitment were generally accurate when the following thresholds for detection were applied: (i) ≥10 kb contig lengths to define populations, (ii) coverage defined from reads mapping at ≥90% identity, and (iii) ≥75% of contig length with ≥1 × coverage. Finally, although data are limited to the most abundant viruses in a community, alpha and beta diversity patterns were robustly estimated (±10%) when comparing samples of similar sequencing depth, but more divergent (up to 80%) when sequencing depth was uneven across the dataset. In the latter cases, the use of normalization methods specifically developed for metagenomes provided the best estimates. Conclusions These simulations provide benchmarks for selecting analysis cut-offs and establish that an optimized sample-to-ecological-inference viromics pipeline is robust for making ecological inferences from natural viral communities. Continued development to better accessing RNA, rare, and/or diverse viral populations and improved reference viral genome availability will alleviate many of viromics remaining limitations.
Collapse
Affiliation(s)
- Simon Roux
- Department of Microbiology, Ohio State University, Columbus, OH, United States of America
| | - Joanne B Emerson
- Department of Microbiology, Ohio State University, Columbus, OH, United States of America
| | - Emiley A Eloe-Fadrosh
- Joint Genome Institute, Department of Energy, Walnut Creek, CA, United States of America
| | - Matthew B Sullivan
- Department of Microbiology, Ohio State University, Columbus, OH, United States of America.,Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, United States of America
| |
Collapse
|
26
|
Improved genome recovery and integrated cell-size analyses of individual uncultured microbial cells and viral particles. Nat Commun 2017; 8:84. [PMID: 28729688 PMCID: PMC5519541 DOI: 10.1038/s41467-017-00128-z] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 06/02/2017] [Indexed: 01/13/2023] Open
Abstract
Microbial single-cell genomics can be used to provide insights into the metabolic potential, interactions, and evolution of uncultured microorganisms. Here we present WGA-X, a method based on multiple displacement amplification of DNA that utilizes a thermostable mutant of the phi29 polymerase. WGA-X enhances genome recovery from individual microbial cells and viral particles while maintaining ease of use and scalability. The greatest improvements are observed when amplifying high G+C content templates, such as those belonging to the predominant bacteria in agricultural soils. By integrating WGA-X with calibrated index-cell sorting and high-throughput genomic sequencing, we are able to analyze genomic sequences and cell sizes of hundreds of individual, uncultured bacteria, archaea, protists, and viral particles, obtained directly from marine and soil samples, in a single experiment. This approach may find diverse applications in microbiology and in biomedical and forensic studies of humans and other multicellular organisms. Single-cell genomics can be used to study uncultured microorganisms. Here, Stepanauskas et al. present a method combining improved multiple displacement amplification and FACS, to obtain genomic sequences and cell size information from uncultivated microbial cells and viral particles in environmental samples.
Collapse
|
27
|
Leuconostoc mesenteroides and Leuconostoc pseudomesenteroides bacteriophages: Genomics and cross-species host ranges. Int J Food Microbiol 2017. [PMID: 28651078 DOI: 10.1016/j.ijfoodmicro.2017.06.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Unveiling virus-host interactions are relevant for understanding the biology and evolution of microbes globally, but in particular, it has also a paramount impact on the manufacture of fermented dairy products. In this study, we aim at characterizing phages infecting the commonly used heterofermentative Leuconostoc spp. on the basis of host range patterns and genome analysis. Host range of six Leuconostoc phages was investigated using three methods (efficiency of plaquing, spot and turbidity tests) against Ln. mesenteroides and Ln. pseudomesenteroides strains. Complete genome sequencing from four out of the six studied Leuconostoc phages were obtained in this work, while the remaining two have been sequenced previously. According to our results, cross-species host specificity was demonstrated, as all phages tested were capable of infecting both Ln. pseudomesenteroides and Ln. mesenteroides strains, although with different efficiency of plaquing (EOP). Phage adsorption rates and ability of low-EOP host strains to propagate phages by crossing the Leuconostoc species' barrier confirm results. At the genome level, phages CHA, CHB, Ln-7, Ln-8 and Ln-9 revealed high similarity with previously characterized phages infecting mostly Ln. mesenteroides strains, while phage LDG was highly similar to phages infecting Ln. pseudomesenteroides. Additionally, correlation between receptor binding protein (RBP) and host range patterns allowed us to unveil a finer clustering of Leuconostoc phages studied into four groups. This is the first report of overlapped phage host ranges between Leuconostoc species.
Collapse
|
28
|
Genomic exploration of individual giant ocean viruses. ISME JOURNAL 2017; 11:1736-1745. [PMID: 28498373 DOI: 10.1038/ismej.2017.61] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 03/02/2017] [Accepted: 03/08/2017] [Indexed: 12/16/2022]
Abstract
Viruses are major pathogens in all biological systems. Virus propagation and downstream analysis remains a challenge, particularly in the ocean where the majority of their microbial hosts remain recalcitrant to current culturing techniques. We used a cultivation-independent approach to isolate and sequence individual viruses. The protocol uses high-speed fluorescence-activated virus sorting flow cytometry, multiple displacement amplification (MDA), and downstream genomic sequencing. We focused on 'giant viruses' that are readily distinguishable by flow cytometry. From a single-milliliter sample of seawater collected from off the dock at Boothbay Harbor, ME, USA, we sorted almost 700 single virus particles, and subsequently focused on a detailed genome analysis of 12. A wide diversity of viruses was identified that included Iridoviridae, extended Mimiviridae and even a taxonomically novel (unresolved) giant virus. We discovered a viral metacaspase homolog in one of our sorted virus particles and discussed its implications in rewiring host metabolism to enhance infection. In addition, we demonstrated that viral metacaspases are widespread in the ocean. We also discovered a virus that contains both a reverse transcriptase and a transposase; although highly speculative, we suggest such a genetic complement would potentially allow this virus to exploit a latency propagation mechanism. Application of single virus genomics provides a powerful opportunity to circumvent cultivation of viruses, moving directly to genomic investigation of naturally occurring viruses, with the assurance that the sequence data is virus-specific, non-chimeric and contains no cellular contamination.
Collapse
|
29
|
Parmar KM, Gaikwad SL, Dhakephalkar PK, Kothari R, Singh RP. Intriguing Interaction of Bacteriophage-Host Association: An Understanding in the Era of Omics. Front Microbiol 2017; 8:559. [PMID: 28439260 PMCID: PMC5383658 DOI: 10.3389/fmicb.2017.00559] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/16/2017] [Indexed: 01/09/2023] Open
Abstract
Innovations in next-generation sequencing technology have introduced new avenues in microbial studies through “omics” approaches. This technology has considerably augmented the knowledge of the microbial world without isolation prior to their identification. With an enormous volume of bacterial “omics” data, considerable attempts have been recently invested to improve an insight into virosphere. The interplay between bacteriophages and their host has created a significant influence on the biogeochemical cycles, microbial diversity, and bacterial population regulation. This review highlights various concepts such as genomics, transcriptomics, proteomics, and metabolomics to infer the phylogenetic affiliation and function of bacteriophages and their impact on diverse microbial communities. Omics technologies illuminate the role of bacteriophage in an environment, the influences of phage proteins on the bacterial host and provide information about the genes important for interaction with bacteria. These investigations will reveal some of bio-molecules and biomarkers of the novel phage which demand to be unveiled.
Collapse
Affiliation(s)
| | | | | | - Ramesh Kothari
- Department of Biosciences, Saurashtra UniversityRajkot, India
| | | |
Collapse
|
30
|
Moller AG, Liang C. Determining virus-host interactions and glycerol metabolism profiles in geographically diverse solar salterns with metagenomics. PeerJ 2017; 5:e2844. [PMID: 28097058 PMCID: PMC5228507 DOI: 10.7717/peerj.2844] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 11/29/2016] [Indexed: 01/12/2023] Open
Abstract
Solar salterns are excellent model ecosystems for studying virus-microbial interactions because of their low microbial diversity, environmental stability, and high viral density. By using the power of CRISPR spacers to link viruses to their prokaryotic hosts, we explored virus-host interactions in geographically diverse salterns. Using taxonomic profiling, we identified hosts such as archaeal Haloquadratum, Halorubrum, and Haloarcula and bacterial Salinibacter, and we found that community composition related to not only salinity but also local environmental dynamics. Characterizing glycerol metabolism genes in these metagenomes suggested Halorubrum and Haloquadratum possess most dihydroxyacetone kinase genes while Salinibacter possesses most glycerol-3-phosphate dehydrogenase genes. Using two different methods, we detected fewer CRISPR spacers in Haloquadratum-dominated compared with Halobacteriaceae-dominated saltern metagenomes. After CRISPR detection, spacers were aligned against haloviral genomes to map virus to host. While most alignments for each saltern metagenome linked viruses to Haloquadratum walsbyi, there were also alignments indicating interactions with the low abundance taxa Haloarcula and Haloferax. Further examination of the dinucleotide and trinucleotide usage differences between paired viruses and their hosts confirmed viruses and hosts had similar nucleotide usage signatures. Detection of cas genes in the salterns supported the possibility of CRISPR activity. Taken together, our studies suggest similar virus-host interactions exist in different solar salterns and that the glycerol metabolism gene dihydroxyacetone kinase is associated with Haloquadratum and Halorubrum.
Collapse
Affiliation(s)
| | - Chun Liang
- Department of Biology, Miami University, Oxford, OH, United States
| |
Collapse
|
31
|
Di Meglio L, Santos F, Gomariz M, Almansa C, López C, Antón J, Nercessian D. Seasonal dynamics of extremely halophilic microbial communities in three Argentinian salterns. FEMS Microbiol Ecol 2016; 92:fiw184. [PMID: 27604253 DOI: 10.1093/femsec/fiw184] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2016] [Indexed: 11/13/2022] Open
Abstract
Seasonal sampling was carried out at three Argentinian salterns, Salitral Negro (SN), Colorada Grande (CG) and Guatraché (G), to analyze abiotic parameters and microbial diversity and dynamics. Microbial assemblages were correlated to environmental factors by statistical analyses. Principal component analysis of the environmental data grouped SN and CG samples separately from G samples owing to G's higher pH values and sulfate concentration. Differences in microbial assemblages were also found. Many archaeal sequences belonged to uncultured members of Haloquadratum and Haloquadratum-related genera, with different environmental optima. Notably, nearly half of the archaeal sequences were affiliated to the recently described 'Candidatus Haloredividus' (phylum Nanohaloarchaeota), not previously detected in salt-saturated environments. Most bacterial sequences belonged to Salinibacter representatives, while sequences affiliated to the recently described genus Spiribacter were also found. Seasonal analysis showed at least 40% of the microbiota from the three salterns was prevalent through the year, indicating they are well adapted to environmental fluctuations. On the other hand, a minority of archaeal and bacterial sequences were found to be seasonally distributed. Five viral morphotypes and also eukaryal predators were detected, suggesting different mechanisms for controlling prokaryotic numbers. Notably, Guatraché was the saltern that harbored the highest virus-to-cell ratios reported to date for hypersaline environments.
Collapse
Affiliation(s)
- Leonardo Di Meglio
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, UNMDP - CONICET, Funes 3250 4° nivel, 7600 Mar del Plata, Argentina
| | - Fernando Santos
- Departamento de Fisiología, Genética y Microbiología, Facultad de Ciencias, Universidad de Alicante, 03690 San Vicente del Raspeig, España
| | - María Gomariz
- Departamento de Fisiología, Genética y Microbiología, Facultad de Ciencias, Universidad de Alicante, 03690 San Vicente del Raspeig, España
| | - Cristina Almansa
- Servicios Técnicos de Investigación (SSTTI), Unidad de Microscopía, Universidad de Alicante, Alicante, 03690 San Vicente del Raspeig, España
| | - Cristina López
- Departamento de Fisiología, Genética y Microbiología, Facultad de Ciencias, Universidad de Alicante, 03690 San Vicente del Raspeig, España
| | - Josefa Antón
- Departamento de Fisiología, Genética y Microbiología, Facultad de Ciencias, Universidad de Alicante, 03690 San Vicente del Raspeig, España
| | - Débora Nercessian
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, UNMDP - CONICET, Funes 3250 4° nivel, 7600 Mar del Plata, Argentina
| |
Collapse
|
32
|
Atanasova NS, Bamford DH, Oksanen HM. Virus-host interplay in high salt environments. ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:431-444. [PMID: 26929102 DOI: 10.1111/1758-2229.12385] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 01/14/2016] [Indexed: 06/05/2023]
Abstract
Interaction of viruses and cells has tremendous impact on cellular and viral evolution, nutrient cycling and decay of organic matter. Thus, viruses can indirectly affect complex processes such as climate change and microbial pathogenicity. During recent decades, studies on extreme environments have introduced us to archaeal viruses and viruses infecting extremophilic bacteria or eukaryotes. Hypersaline environments are known to contain strikingly high numbers of viruses (∼10(9) particles per ml). Halophilic archaea, bacteria and eukaryotes inhabiting hypersaline environments have only a few cellular predators, indicating that the role of viruses is highly important in these ecosystems. Viruses thriving in high salt are called haloviruses and to date more than 100 such viruses have been described. Virulent, temperate, and persistent halovirus life cycles have been observed among the known isolates including the recently described SNJ1-SNJ2 temperate virus pair which is the first example of an interplay between two haloviruses in one host cell. In addition to direct virus and cell isolations, metagenomics have provided a wealth of information about virus-host dynamics in hypersaline environments suggesting that halovirus populations and halophilic microorganisms are dynamic over time and spatially distributed around the highly saline environments on the Earth.
Collapse
Affiliation(s)
- Nina S Atanasova
- Department of Biosciences and Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Dennis H Bamford
- Department of Biosciences and Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Hanna M Oksanen
- Department of Biosciences and Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
33
|
Holmfeldt K, Solonenko N, Howard-Varona C, Moreno M, Malmstrom RR, Blow MJ, Sullivan MB. Large-scale maps of variable infection efficiencies in aquatic Bacteroidetes phage-host model systems. Environ Microbiol 2016; 18:3949-3961. [PMID: 27235779 DOI: 10.1111/1462-2920.13392] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/21/2015] [Indexed: 01/21/2023]
Abstract
Microbes drive ecosystem functioning and their viruses modulate these impacts through mortality, gene transfer and metabolic reprogramming. Despite the importance of virus-host interactions and likely variable infection efficiencies of individual phages across hosts, such variability is seldom quantified. Here, we quantify infection efficiencies of 38 phages against 19 host strains in aquatic Cellulophaga (Bacteroidetes) phage-host model systems. Binary data revealed that some phages infected only one strain while others infected 17, whereas quantitative data revealed that efficiency of infection could vary 10 orders of magnitude, even among phages within one population. This provides a baseline for understanding and modeling intrapopulation host range variation. Genera specific host ranges were also informative. For example, the Cellulophaga Microviridae, showed a markedly broader intra-species host range than previously observed in Escherichia coli systems. Further, one phage genus, Cba41, was examined to investigate nonheritable changes in plating efficiency and burst size that depended on which host strain it most recently infected. While consistent with host modification of phage DNA, no differences in nucleotide sequence or DNA modifications were detected, leaving the observation repeatable, but the mechanism unresolved. Overall, this study highlights the importance of quantitatively considering replication variations in studies of phage-host interactions.
Collapse
Affiliation(s)
- Karin Holmfeldt
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, USA.,Department of Biology and Environmental Sciences, Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Natalie Solonenko
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, USA
| | | | - Mario Moreno
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, USA
| | | | | | - Matthew B Sullivan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, USA
| |
Collapse
|
34
|
Villarroel J, Kleinheinz KA, Jurtz VI, Zschach H, Lund O, Nielsen M, Larsen MV. HostPhinder: A Phage Host Prediction Tool. Viruses 2016; 8:E116. [PMID: 27153081 PMCID: PMC4885074 DOI: 10.3390/v8050116] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/14/2016] [Accepted: 04/19/2016] [Indexed: 01/11/2023] Open
Abstract
The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k) is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST and significantly outperforming BLAST on phages for which both had predictions. HostPhinder predictions on phage draft genomes from the INTESTI phage cocktail corresponded well with the advertised targets of the cocktail. Our study indicates that for most phages genomic similarity correlates well with related bacterial hosts. HostPhinder is available as an interactive web service [1] and as a stand alone download from the Docker registry [2].
Collapse
Affiliation(s)
- Julia Villarroel
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Kortine Annina Kleinheinz
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Vanessa Isabell Jurtz
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Henrike Zschach
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Ole Lund
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Morten Nielsen
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
- Instituto de Investigaciones Biotecnológicas, Universidad de San Martín, CP(1650) San Martín, Prov. de Buenos Aires, Argentina.
| | - Mette Voldby Larsen
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| |
Collapse
|
35
|
Crits-Christoph A, Gelsinger DR, Ma B, Wierzchos J, Ravel J, Davila A, Casero MC, DiRuggiero J. Functional interactions of archaea, bacteria and viruses in a hypersaline endolithic community. Environ Microbiol 2016; 18:2064-77. [DOI: 10.1111/1462-2920.13259] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/08/2016] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Bing Ma
- Institute for Genome Sciences, University of Maryland School of Medicine; Baltimore MD USA
| | - Jacek Wierzchos
- Department of Biochemistry and Microbial Ecology; Museo Nacional de Ciencias Naturales - Consejo Superior de Investigaciones Científicas; Madrid Spain
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland School of Medicine; Baltimore MD USA
| | | | - M. Cristina Casero
- Department of Biochemistry and Microbial Ecology; Museo Nacional de Ciencias Naturales - Consejo Superior de Investigaciones Científicas; Madrid Spain
| | | |
Collapse
|
36
|
Vavourakis CD, Ghai R, Rodriguez-Valera F, Sorokin DY, Tringe SG, Hugenholtz P, Muyzer G. Metagenomic Insights into the Uncultured Diversity and Physiology of Microbes in Four Hypersaline Soda Lake Brines. Front Microbiol 2016; 7:211. [PMID: 26941731 PMCID: PMC4766312 DOI: 10.3389/fmicb.2016.00211] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/08/2016] [Indexed: 11/13/2022] Open
Abstract
Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first "metagenomic snapshots" of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia) covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that the top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha-, and Gamma-proteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter, and Rhodobaca) and chemolithotrophic sulfur oxidizers (Thioalkalivibrio) were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria, and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermaceae-related draft genome were indicative of a "salt-in" strategy of osmotic adaptation. The primary catabolic and respiratory pathways shared among all available reference genomes of Nanohaloarchaea and our novel genome reconstructions remain incomplete, but point to a primarily fermentative lifestyle. Encoded xenorhodopsins found in most drafts suggest that light plays an important role in the ecology of Nanohaloarchaea. Putative encoded halolysins and laccase-like oxidases might indicate the potential for extracellular degradation of proteins and peptides, and phenolic or aromatic compounds.
Collapse
Affiliation(s)
- Charlotte D. Vavourakis
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, Netherlands
| | - Rohit Ghai
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel HernándezSan Juan de Alicante, Spain
- Department of Aquatic Microbial Ecology, Biology Centre of the Czech Academy of Sciences, Institute of HydrobiologyČeské Budějovice, Czech Republic
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel HernándezSan Juan de Alicante, Spain
| | - Dimitry Y. Sorokin
- Research Centre of Biotechnology, Winogradsky Institute of Microbiology, Russian Academy of SciencesMoscow, Russia
- Department of Biotechnology, Delft University of TechnologyDelft, Netherlands
| | | | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, Netherlands
| |
Collapse
|
37
|
Acidianus Tailed Spindle Virus: a New Archaeal Large Tailed Spindle Virus Discovered by Culture-Independent Methods. J Virol 2016; 90:3458-68. [PMID: 26763997 DOI: 10.1128/jvi.03098-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/07/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The field of viral metagenomics has expanded our understanding of viral diversity from all three domains of life (Archaea, Bacteria, and Eukarya). Traditionally, viral metagenomic studies provide information about viral gene content but rarely provide knowledge about virion morphology and/or cellular host identity. Here we describe a new virus, Acidianus tailed spindle virus (ATSV), initially identified by bioinformatic analysis of viral metagenomic data sets from a high-temperature (80°C) acidic (pH 2) hot spring located in Yellowstone National Park, followed by more detailed characterization using only environmental samples without dependency on culturing. Characterization included the identification of the large tailed spindle virion morphology, determination of the complete 70.8-kb circular double-stranded DNA (dsDNA) viral genome content, and identification of its cellular host. Annotation of the ATSV genome revealed a potential three-domain gene product containing an N-terminal leucine-rich repeat domain, followed by a likely posttranslation regulatory region consisting of high serine and threonine content, and a C-terminal ESCRT-III domain, suggesting interplay with the host ESCRT system. The host of ATSV, which is most closely related to Acidianus hospitalis, was determined by a combination of analysis of cellular clustered regularly interspaced short palindromic repeat (CRISPR)/Cas loci and dual viral and cellular fluorescence in situ hybridization (viral FISH) analysis of environmental samples and confirmed by culture-based infection studies. This work provides an expanded pathway for the discovery, isolation, and characterization of new viruses using culture-independent approaches and provides a platform for predicting and confirming virus hosts. IMPORTANCE Virus discovery and characterization have been traditionally accomplished by using culture-based methods. While a valuable approach, it is limited by the availability of culturable hosts. In this research, we report a virus-centered approach to virus discovery and characterization, linking viral metagenomic sequences to a virus particle, its sequenced genome, and its host directly in environmental samples, without using culture-dependent methods. This approach provides a pathway for the discovery, isolation, and characterization of new viruses. While this study used an acidic hot spring environment to characterize a new archaeal virus, Acidianus tailed spindle virus (ATSV), the approach can be generally applied to any environment to expand knowledge of virus diversity in all three domains of life.
Collapse
|
38
|
Adriaenssens EM, van Zyl LJ, Cowan DA, Trindade MI. Metaviromics of Namib Desert Salt Pans: A Novel Lineage of Haloarchaeal Salterproviruses and a Rich Source of ssDNA Viruses. Viruses 2016; 8:v8010014. [PMID: 26761024 PMCID: PMC4728574 DOI: 10.3390/v8010014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 11/26/2015] [Accepted: 12/14/2015] [Indexed: 11/26/2022] Open
Abstract
Viral communities of two different salt pans located in the Namib Desert, Hosabes and Eisfeld, were investigated using a combination of multiple displacement amplification of metaviromic DNA and deep sequencing, and provided comprehensive sequence data on both ssDNA and dsDNA viral community structures. Read and contig annotations through online pipelines showed that the salt pans harbored largely unknown viral communities. Through network analysis, we were able to assign a large portion of the unknown reads to a diverse group of ssDNA viruses. Contigs belonging to the subfamily Gokushovirinae were common in both environmental datasets. Analysis of haloarchaeal virus contigs revealed the presence of three contigs distantly related with His1, indicating a possible new lineage of salterproviruses in the Hosabes playa. Based on viral richness and read mapping analyses, the salt pan metaviromes were novel and most closely related to each other while showing a low degree of overlap with other environmental viromes.
Collapse
Affiliation(s)
- Evelien M Adriaenssens
- Centre for Microbial Ecology and Genomics, Genomics Research Institute, University of Pretoria, Natural Sciences II, Lynnwood Road, 0002 Pretoria, South Africa.
| | - Leonardo Joaquim van Zyl
- Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, 7535 Bellville, Cape Town, South Africa.
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Genomics Research Institute, University of Pretoria, Natural Sciences II, Lynnwood Road, 0002 Pretoria, South Africa.
| | - Marla I Trindade
- Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, 7535 Bellville, Cape Town, South Africa.
| |
Collapse
|
39
|
Single-Cell-Genomics-Facilitated Read Binning of Candidate Phylum EM19 Genomes from Geothermal Spring Metagenomes. Appl Environ Microbiol 2015; 82:992-1003. [PMID: 26637598 DOI: 10.1128/aem.03140-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/12/2015] [Indexed: 12/17/2022] Open
Abstract
The vast majority of microbial life remains uncatalogued due to the inability to cultivate these organisms in the laboratory. This "microbial dark matter" represents a substantial portion of the tree of life and of the populations that contribute to chemical cycling in many ecosystems. In this work, we leveraged an existing single-cell genomic data set representing the candidate bacterial phylum "Calescamantes" (EM19) to calibrate machine learning algorithms and define metagenomic bins directly from pyrosequencing reads derived from Great Boiling Spring in the U.S. Great Basin. Compared to other assembly-based methods, taxonomic binning with a read-based machine learning approach yielded final assemblies with the highest predicted genome completeness of any method tested. Read-first binning subsequently was used to extract Calescamantes bins from all metagenomes with abundant Calescamantes populations, including metagenomes from Octopus Spring and Bison Pool in Yellowstone National Park and Gongxiaoshe Spring in Yunnan Province, China. Metabolic reconstruction suggests that Calescamantes are heterotrophic, facultative anaerobes, which can utilize oxidized nitrogen sources as terminal electron acceptors for respiration in the absence of oxygen and use proteins as their primary carbon source. Despite their phylogenetic divergence, the geographically separate Calescamantes populations were highly similar in their predicted metabolic capabilities and core gene content, respiring O2, or oxidized nitrogen species for energy conservation in distant but chemically similar hot springs.
Collapse
|
40
|
Ventosa A, de la Haba RR, Sánchez-Porro C, Papke RT. Microbial diversity of hypersaline environments: a metagenomic approach. Curr Opin Microbiol 2015; 25:80-7. [PMID: 26056770 DOI: 10.1016/j.mib.2015.05.002] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/29/2015] [Accepted: 05/01/2015] [Indexed: 10/23/2022]
Abstract
Recent studies based on metagenomics and other molecular techniques have permitted a detailed knowledge of the microbial diversity and metabolic activities of microorganisms in hypersaline environments. The current accepted model of community structure in hypersaline environments is that the square archaeon Haloquadratum waslbyi, the bacteroidete Salinibacter ruber and nanohaloarchaea are predominant members at higher salt concentrations, while more diverse archaeal and bacterial taxa are observed in habitats with intermediate salinities. Additionally, metagenomic studies may provide insight into the isolation and characterization of the principal microbes in these habitats, such as the recently described gammaproteobacterium Spiribacter salinus.
Collapse
Affiliation(s)
- Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain.
| | - Rafael R de la Haba
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, 06269 Storrs, CT, USA
| |
Collapse
|
41
|
Snyder JC, Bolduc B, Young MJ. 40 Years of archaeal virology: Expanding viral diversity. Virology 2015; 479-480:369-78. [PMID: 25866378 DOI: 10.1016/j.virol.2015.03.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/07/2015] [Accepted: 03/17/2015] [Indexed: 10/23/2022]
Abstract
The first archaeal virus was isolated over 40 years ago prior to the recognition of the three domain structure of life. In the ensuing years, our knowledge of Archaea and their viruses has increased, but they still remain the most mysterious of life's three domains. Currently, over 100 archaeal viruses have been discovered, but few have been described in biochemical or structural detail. However, those that have been characterized have revealed a new world of structural, biochemical and genetic diversity. Several model systems for studying archaeal virus-host interactions have been developed, revealing evolutionary linkages between viruses infecting the three domains of life, new viral lysis systems, and unusual features of host-virus interactions. It is likely that the study of archaeal viruses will continue to provide fertile ground for fundamental discoveries in virus diversity, structure and function.
Collapse
Affiliation(s)
- Jamie C Snyder
- Department of Biological Sciences, California State Polytechnic University - Pomona, Pomona, CA, USA
| | - Benjamin Bolduc
- Departments of Plant Sciences and Microbiology, Montana State University, Bozeman, MT, USA
| | - Mark J Young
- Departments of Plant Sciences and Microbiology, Montana State University, Bozeman, MT, USA.
| |
Collapse
|
42
|
Stepanauskas R. Wiretapping into microbial interactions by single cell genomics. Front Microbiol 2015; 6:258. [PMID: 25904902 PMCID: PMC4389542 DOI: 10.3389/fmicb.2015.00258] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/16/2015] [Indexed: 11/13/2022] Open
|