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Denison ER, Zepernick BN, McKay RML, Wilhelm SW. Metatranscriptomic analysis reveals dissimilarity in viral community activity between an ice-free and ice-covered winter in Lake Erie. mSystems 2024; 9:e0075324. [PMID: 38940524 PMCID: PMC11264689 DOI: 10.1128/msystems.00753-24] [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: 05/31/2024] [Accepted: 06/10/2024] [Indexed: 06/29/2024] Open
Abstract
Winter is a relatively under-studied season in freshwater ecology. The paucity of wintertime surveys has led to a lack of knowledge regarding microbial community activity during the winter in Lake Erie, a North American Great Lake. Viruses shape microbial communities and regulate biogeochemical cycles by acting as top-down controls, yet very few efforts have been made to examine active virus populations during the winter in Lake Erie. Furthermore, climate change-driven declines in seasonal ice cover have been shown to influence microbial community structure, but no studies have compared viral community activity between different ice cover conditions. We surveyed surface water metatranscriptomes for viral hallmark genes as a proxy for active virus populations and compared activity metrics between ice-covered and ice-free conditions from two sampled winters. Transcriptionally active viral communities were detected in both winters, spanning diverse phylogenetic clades of putative bacteriophage (Caudoviricetes), giant viruses (Nucleocytoviricota, or NCLDV), and RNA viruses (Orthornavirae). However, viral community activity metrics revealed pronounced differences between the ice-covered and ice-free winters. Viral community composition was distinct between winters and viral hallmark gene richness was reduced in the ice-covered relative to the ice-free conditions. In addition, the observed differences in viral communities correlated with microbial community activity metrics. Overall, these findings contribute to our understanding of the viral populations that are active during the winter in Lake Erie and suggest that viral community activity may be associated with ice cover extent.IMPORTANCEAs seasonal ice cover is projected to become increasingly rare on large temperate lakes, there is a need to understand how microbial communities might respond to changing ice conditions. Although it is widely recognized that viruses impact microbial community structure and function, there is little known regarding wintertime viral activity or the relationship between viral activity and ice cover extent. Our metatranscriptomic analyses indicated that viruses were transcriptionally active in the winter surface waters of Lake Erie. These findings also expanded the known diversity of viral lineages in the Great Lakes. Notably, viral community activity metrics were significantly different between the two sampled winters. The pronounced differences we observed in active viral communities between the ice-covered and ice-free samples merit further research regarding how viral communities will function in future, potentially ice-free, freshwater systems.
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Affiliation(s)
| | | | - R. Michael L. McKay
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada
| | - Steven W. Wilhelm
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
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Zhang H, Zhang H, Du H, Yu X, Xu Y. The insights into the phage communities of fermented foods in the age of viral metagenomics. Crit Rev Food Sci Nutr 2024:1-13. [PMID: 38214674 DOI: 10.1080/10408398.2023.2299323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Phages play a critical role in the assembly and regulation of fermented food microbiome through lysis and lysogenic lifestyle, which in turn affects the yield and quality of fermented foods. Therefore, it is important to investigate and characterize the diversity and function of phages under complex microbial communities and nutrient substrate conditions to provide novel insights into the regulation of traditional spontaneous fermentation. Viral metagenomics has gradually garnered increasing attention in fermented food research to elucidate phage functions and characterize the interactions between phages and the microbial community. Advances in this technology have uncovered a wide range of phages associated with the production of traditional fermented foods and beverages. This paper reviews the common methods of viral metagenomics applied in fermented food research, and summarizes the ecological functions of phages in traditional fermented foods. In the future, combining viral metagenomics with culturable methods and metagenomics will broaden the scope of research on fermented food systems, revealing the complex role of phages and intricate phage-bacterium interactions.
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Affiliation(s)
- Huadong Zhang
- Laboratory of Brewing Microbiology and Applied Enzymology, The Key Laboratory of Industrial Biotechnology, Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Hongxia Zhang
- College of Life Sciences, Shanxi Normal University, Taiyuan, Shanxi, China
| | - Hai Du
- Laboratory of Brewing Microbiology and Applied Enzymology, The Key Laboratory of Industrial Biotechnology, Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Xiaowei Yu
- Laboratory of Brewing Microbiology and Applied Enzymology, The Key Laboratory of Industrial Biotechnology, Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Yan Xu
- Laboratory of Brewing Microbiology and Applied Enzymology, The Key Laboratory of Industrial Biotechnology, Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
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3
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Tsiola A, Michoud G, Daffonchio D, Fodelianakis S, Giannakourou A, Malliarakis D, Pavlidou A, Pitta E, Psarra S, Santi I, Zeri C, Pitta P. Depth-driven patterns in lytic viral diversity, auxiliary metabolic gene content, and productivity in offshore oligotrophic waters. Front Microbiol 2023; 14:1271535. [PMID: 38029212 PMCID: PMC10653327 DOI: 10.3389/fmicb.2023.1271535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Marine viruses regulate microbial population dynamics and biogeochemical cycling in the oceans. The ability of viruses to manipulate hosts' metabolism through the expression of viral auxiliary metabolic genes (AMGs) was recently highlighted, having important implications in energy production and flow in various aquatic environments. Up to now, the presence and diversity of viral AMGs is studied using -omics data, and rarely using quantitative measures of viral activity alongside. Methods In the present study, four depth layers (5, 50, 75, and 1,000 m) with discrete hydrographic features were sampled in the Eastern Mediterranean Sea; we studied lytic viral community composition and AMG content through metagenomics, and lytic production rates through the viral reduction approach in the ultra-oligotrophic Levantine basin where knowledge regarding viral actions is rather limited. Results and Discussion Our results demonstrate depth-dependent patterns in viral diversity and AMG content, related to differences in temperature, nutrients availability, and host bacterial productivity and abundance. Although lytic viral production rates were similar along the water column, the virus-to-bacteria ratio was higher and the particular set of AMGs was more diverse in the bathypelagic (1,000 m) than the shallow epipelagic (5, 50, and 75 m) layers, revealing that the quantitative effect of viruses on their hosts may be the same along the water column through the intervention of different AMGs. In the resource- and energy-limited bathypelagic waters of the Eastern Mediterranean, the detected AMGs could divert hosts' metabolism toward energy production, through a boost in gluconeogenesis, fatty-acid and glycan biosynthesis and metabolism, and sulfur relay. Near the deep-chlorophyll maximum depth, an exceptionally high percentage of AMGs related to photosynthesis was noticed. Taken together our findings suggest that the roles of viruses in the deep sea might be even more important than previously thought as they seem to orchestrate energy acquisition and microbial community dynamics, and thus, biogeochemical turnover in the oceans.
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Affiliation(s)
- Anastasia Tsiola
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Heraklion Crete, Greece
| | - Grégoire Michoud
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Daniele Daffonchio
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Stilianos Fodelianakis
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Antonia Giannakourou
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Anavyssos, Attiki, Greece
| | | | - Alexandra Pavlidou
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Anavyssos, Attiki, Greece
| | - Elli Pitta
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Anavyssos, Attiki, Greece
| | - Stella Psarra
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Heraklion Crete, Greece
| | - Ioulia Santi
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Heraklion Crete, Greece
| | - Christina Zeri
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Anavyssos, Attiki, Greece
| | - Paraskevi Pitta
- Institute of Oceanography, Hellenic Centre for Marine Research (HCMR), Heraklion Crete, Greece
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4
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Trubl G, Stedman KM, Bywaters KF, Matula EE, Sommers P, Roux S, Merino N, Yin J, Kaelber JT, Avila-Herrera A, Johnson PA, Johnson JC, Borges S, Weber PK, Pett-Ridge J, Boston PJ. Astrovirology: how viruses enhance our understanding of life in the Universe. INTERNATIONAL JOURNAL OF ASTROBIOLOGY 2023; 22:247-271. [PMID: 38046673 PMCID: PMC10691837 DOI: 10.1017/s1473550423000058] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Viruses are the most numerically abundant biological entities on Earth. As ubiquitous replicators of molecular information and agents of community change, viruses have potent effects on the life on Earth, and may play a critical role in human spaceflight, for life-detection missions to other planetary bodies and planetary protection. However, major knowledge gaps constrain our understanding of the Earth's virosphere: (1) the role viruses play in biogeochemical cycles, (2) the origin(s) of viruses and (3) the involvement of viruses in the evolution, distribution and persistence of life. As viruses are the only replicators that span all known types of nucleic acids, an expanded experimental and theoretical toolbox built for Earth's viruses will be pivotal for detecting and understanding life on Earth and beyond. Only by filling in these knowledge and technical gaps we will obtain an inclusive assessment of how to distinguish and detect life on other planetary surfaces. Meanwhile, space exploration requires life-support systems for the needs of humans, plants and their microbial inhabitants. Viral effects on microbes and plants are essential for Earth's biosphere and human health, but virus-host interactions in spaceflight are poorly understood. Viral relationships with their hosts respond to environmental changes in complex ways which are difficult to predict by extrapolating from Earth-based proxies. These relationships should be studied in space to fully understand how spaceflight will modulate viral impacts on human health and life-support systems, including microbiomes. In this review, we address key questions that must be examined to incorporate viruses into Earth system models, life-support systems and life detection. Tackling these questions will benefit our efforts to develop planetary protection protocols and further our understanding of viruses in astrobiology.
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Affiliation(s)
- Gareth Trubl
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Kenneth M. Stedman
- Center for Life in Extreme Environments, Department of Biology, Portland State University, Portland, OR, USA
| | | | | | | | - Simon Roux
- DOE Joint Genome Institute, Berkeley, CA, USA
| | - Nancy Merino
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - John Yin
- Chemical and Biological Engineering, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
| | - Jason T. Kaelber
- Institute for Quantitative Biomedicine, Rutgers, the State University of New Jersey, Piscataway, NJ, USA
| | - Aram Avila-Herrera
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Peter Anto Johnson
- Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | | | | | - Peter K. Weber
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
- Life & Environmental Sciences Department, University of California Merced, Merced, CA, USA
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Diaz BP, Zelzion E, Halsey K, Gaube P, Behrenfeld M, Bidle KD. Marine phytoplankton downregulate core photosynthesis and carbon storage genes upon rapid mixed layer shallowing. THE ISME JOURNAL 2023:10.1038/s41396-023-01416-x. [PMID: 37156837 DOI: 10.1038/s41396-023-01416-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 04/03/2023] [Accepted: 04/13/2023] [Indexed: 05/10/2023]
Abstract
Marine phytoplankton are a diverse group of photoautotrophic organisms and key mediators in the global carbon cycle. Phytoplankton physiology and biomass accumulation are closely tied to mixed layer depth, but the intracellular metabolic pathways activated in response to changes in mixed layer depth remain less explored. Here, metatranscriptomics was used to characterize the phytoplankton community response to a mixed layer shallowing (from 233 to 5 m) over the course of two days during the late spring in the Northwest Atlantic. Most phytoplankton genera downregulated core photosynthesis, carbon storage, and carbon fixation genes as the system transitioned from a deep to a shallow mixed layer and shifted towards catabolism of stored carbon supportive of rapid cell growth. In contrast, phytoplankton genera exhibited divergent transcriptional patterns for photosystem light harvesting complex genes during this transition. Active virus infection, taken as the ratio of virus to host transcripts, increased in the Bacillariophyta (diatom) phylum and decreased in the Chlorophyta (green algae) phylum upon mixed layer shallowing. A conceptual model is proposed to provide ecophysiological context for our findings, in which integrated light limitation and lower division rates during transient deep mixing are hypothesized to disrupt resource-driven, oscillating transcript levels related to photosynthesis, carbon fixation, and carbon storage. Our findings highlight shared and unique transcriptional response strategies within phytoplankton communities acclimating to the dynamic light environment associated with transient deep mixing and shallowing events during the annual North Atlantic bloom.
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Affiliation(s)
- Ben P Diaz
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ, 08901, USA
- Biotechnology & Bioengineering, Sandia National Laboratories, 7011 East Avenue, Livermore, CA, 94550, USA
| | - Ehud Zelzion
- Office of Advanced Research Computing, Rutgers University, Piscataway, NJ, 08854, USA
| | - Kimberly Halsey
- Department of Microbiology, Oregon State University, Corvallis, OR, 97331, USA
| | - Peter Gaube
- Applied Physics Laboratory, University of Washington, Seattle, WA, 98105, USA
| | - Michael Behrenfeld
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Kay D Bidle
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ, 08901, USA.
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6
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Whaley-Martin KJ, Chen LX, Nelson TC, Gordon J, Kantor R, Twible LE, Marshall S, McGarry S, Rossi L, Bessette B, Baron C, Apte S, Banfield JF, Warren LA. O 2 partitioning of sulfur oxidizing bacteria drives acidity and thiosulfate distributions in mining waters. Nat Commun 2023; 14:2006. [PMID: 37037821 PMCID: PMC10086054 DOI: 10.1038/s41467-023-37426-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 03/14/2023] [Indexed: 04/12/2023] Open
Abstract
The acidification of water in mining areas is a global environmental issue primarily catalyzed by sulfur-oxidizing bacteria (SOB). Little is known about microbial sulfur cycling in circumneutral pH mine tailing impoundment waters. Here we investigate biological sulfur oxidation over four years in a mine tailings impoundment water cap, integrating aqueous sulfur geochemistry, genome-resolved metagenomics and metatranscriptomics. The microbial community is consistently dominated by neutrophilic, chemolithoautotrophic SOB (relative abundances of ~76% in 2015, ~55% in 2016/2017 and ~60% in 2018). Results reveal two SOB strategies alternately dominate across the four years, influencing acid generation and sulfur speciation. Under oxic conditions, novel Halothiobacillus drive lower pH conditions (as low as 4.3) and lower [S2O32-] via the complete Sox pathway coupled to O2. Under anoxic conditions, Thiobacillus spp. dominate in activity, via the incomplete Sox and rDSR pathways coupled to NO3-, resulting in higher [S2O32-] and no net significant acidity generation. This study provides genomic evidence explaining acidity generation and thiosulfate accumulation patterns in a circumneutral mine tailing impoundment and has significant environmental applications in preventing the discharge of sulfur compounds that can impact downstream environments. These insights illuminate opportunities for in situ biotreatment of reduced sulfur compounds and prediction of acidification events using gene-based monitoring and in situ RNA detection.
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Affiliation(s)
- Kelly J Whaley-Martin
- University of Toronto, Toronto, ON, Canada
- Environmental Resources management (ERM), Toronto, ON, Canada
| | - Lin-Xing Chen
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | | | | | - Rose Kantor
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | | | - Stephanie Marshall
- Environmental Resources management (ERM), Toronto, ON, Canada
- McMaster University, Hamilton, ON, Canada
| | - Sam McGarry
- Glencore, Sudbury Integrated Nickel Operations, Sudbury, ON, Canada
| | | | | | | | - Simon Apte
- CSIRO Land and Water, Clayton, NSW, Australia
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA.
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7
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Yuan L, Ju F. Potential Auxiliary Metabolic Capabilities and Activities Reveal Biochemical Impacts of Viruses in Municipal Wastewater Treatment Plants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5485-5498. [PMID: 36947091 DOI: 10.1021/acs.est.2c07800] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Viruses influence biogeochemical cycles in oceans, freshwater, soil, and human gut through infection and by modulating virocell metabolism through virus-encoded auxiliary metabolic genes (vAMGs). However, the geographical distribution, potential metabolic function, and engineering significance of vAMGs in wastewater treatment plants (WWTPs) remain to be explored. Here, 752 single-contig viral genomes with high confidence, 510 of which belonged to Caudovirales, were recovered from the activated sludge metagenomes of 32 geographically distributed WWTPs. A total of 101 vAMGs involved in various metabolic pathways were identified, the most common of which were the queuosine biosynthesis genes folE, queD, and queE and the sulfur metabolism gene cysH. Phylogenetic analysis and virus-host relationship prediction revealed the probable evolutionary histories of vAMGs involved in carbon (acpP and prsA), nitrogen (amoC), sulfur (cysH), and phosphate (phoH) metabolism, which potentially mediate microbial carbon and nutrient cycling. Notably, 11 of the 38 (28.3%) vAMGs identified in the metagenomes with corresponding metatranscriptomes were transcriptionally expressed, implying an active functional state. This meta-analysis provides the first broad catalog of vAMGs in municipal WWTPs and how they may assist in the basic physiological reactions of their microbial hosts or nutrient cycling in the WWTPs, and therefore, may have important effects on the engineering of wastewater treatment processes.
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Affiliation(s)
- Ling Yuan
- Environmental Science and Engineering Department, Zhejiang University, Hangzhou 310012, Zhejiang, China
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou 310030, Zhejiang, China
- Environmental Microbiome and Biotechnology Laboratory (EMBLab), Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou 310030, Zhejiang, China
| | - Feng Ju
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou 310030, Zhejiang, China
- Environmental Microbiome and Biotechnology Laboratory (EMBLab), Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou 310030, Zhejiang, China
- Research Center for Industries of the Future, Westlake University, Hangzhou 310030, Zhejiang, China
- Institute of Advanced Technology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China
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8
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Braga LPP, Schumacher RI. Awaking the dormant virome in the rhizosphere. Mol Ecol 2023; 32:2985-2999. [PMID: 36807953 DOI: 10.1111/mec.16893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/16/2023] [Accepted: 02/06/2023] [Indexed: 02/22/2023]
Abstract
The rhizosphere is a vital soil compartment providing key plant-beneficial functions. However, little is known about the mechanisms driving viral diversity in the rhizosphere. Viruses can establish lytic or lysogenic interactions with their bacterial hosts. In the latter, they assume a dormant state integrated in the host genome and can be awakened by different perturbations that impact host cell physiology, triggering a viral bloom, which is potentially a fundamental mechanism driving soil viral diversity, as 22%-68% of soil bacteria are predicted to harbour dormant viruses. Here we assessed the viral bloom response in rhizospheric viromes by exposing them to three contrasting soil perturbation agents: earthworms, herbicide and antibiotic pollutant. The viromes were next screened for rhizosphere-relevant genes and also used as inoculant on microcosms incubations to test their impacts on pristine microbiomes. Our results show that while post-perturbation viromes diverged from control conditions, viral communities exposed to both herbicide and antibiotic pollutant were more similar to each other than those influenced by earthworms. The latter also favoured an increase in viral populations harbouring genes involved in plant-beneficial functions. Post-perturbation viromes inoculated on soil microcosms changed the diversity of pristine microbiomes, suggesting that viromes are important components of the soil ecological memory driving eco-evolutionary processes that determine future microbiome trajectories according to past events. Our findings demonstrate that viromes are active players in the rhizosphere and need to be considered in efforts to understand and control the microbial processes towards sustainable crop production.
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Affiliation(s)
- Lucas P P Braga
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, Brazil.,Ecosystems and Global Change Group, Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Robert I Schumacher
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, Brazil
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9
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Viruses direct carbon cycling in lake sediments under global change. Proc Natl Acad Sci U S A 2022; 119:e2202261119. [PMID: 36206369 PMCID: PMC9564219 DOI: 10.1073/pnas.2202261119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Global change is altering the vast amount of carbon cycled by microbes between land and freshwater, but how viruses mediate this process is poorly understood. Here, we show that viruses direct carbon cycling in lake sediments, and these impacts intensify with future changes in water clarity and terrestrial organic matter (tOM) inputs. Using experimental tOM gradients within sediments of a clear and a dark boreal lake, we identified 156 viral operational taxonomic units (vOTUs), of which 21% strongly increased with abundances of key bacteria and archaea, identified via metagenome-assembled genomes (MAGs). MAGs included the most abundant prokaryotes, which were themselves associated with dissolved organic matter (DOM) composition and greenhouse gas (GHG) concentrations. Increased abundances of virus-like particles were separately associated with reduced bacterial metabolism and with shifts in DOM toward amino sugars, likely released by cell lysis rather than higher molecular mass compounds accumulating from reduced tOM degradation. An additional 9.6% of vOTUs harbored auxiliary metabolic genes associated with DOM and GHGs. Taken together, these different effects on host dynamics and metabolism can explain why abundances of vOTUs rather than MAGs were better overall predictors of carbon cycling. Future increases in tOM quantity, but not quality, will change viral composition and function with consequences for DOM pools. Given their importance, viruses must now be explicitly considered in efforts to understand and predict the freshwater carbon cycle and its future under global environmental change.
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10
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Antosiak A, Šulčius S, Malec P, Tokodi N, Łobodzińska A, Dziga D. Cyanophage infections reduce photosynthetic activity and expression of CO 2 fixation genes in the freshwater bloom-forming cyanobacterium Aphanizomenon flos-aquae. HARMFUL ALGAE 2022; 116:102215. [PMID: 35710200 DOI: 10.1016/j.hal.2022.102215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 02/20/2022] [Accepted: 02/25/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacteria play a significant role in ecosystem functioning as photosynthetic and CO2 fixing microorganisms. Whether and to what extent cyanophages alter these carbon and energy cycles in their cyanobacterial hosts is still poorly understood. In this study, we investigated changes in photosynthetic activity (PSII), expression of genes associated with the light phase of photosynthesis (psbA, petA, ndhK) and carbon metabolism (rbcL, zwf) as well as intracellular ATP and NADHP concentrations in freshwater bloom-forming filamentous cyanobacterium Aphanizomenon flos-aquae infected by cyanophage vB_AphaS-CL131. We found that PSII activity and expression level of rbcL genes, indicating potential for CO2 fixation, had decreased in response to cyanophage adsorption and DNA injection. During the period of viral DNA replication and assembly, PSII performance and gene expression remained at this decreased level and did not change significantly, indicating lack of transcriptional shutdown by the cyanophage. Combined, these observations suggest that although there is little to no interference between cyanophage DNA replication, host transcription and cellular metabolism, A. flos-aquae underwent a physiological state-shift toward lower efficiency of carbon and energy cycling. This further suggest potential cascading effect for co-occurring non-infected members of the microbial community.
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Affiliation(s)
- Adam Antosiak
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
| | - Sigitas Šulčius
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos str. 2, 08412 Vilnius, Lithuania.
| | - Przemysław Malec
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
| | - Nada Tokodi
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland; Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia.
| | - Antonia Łobodzińska
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
| | - Dariusz Dziga
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
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11
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The OceanDNA MAG catalog contains over 50,000 prokaryotic genomes originated from various marine environments. Sci Data 2022; 9:305. [PMID: 35715423 PMCID: PMC9205870 DOI: 10.1038/s41597-022-01392-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 05/12/2022] [Indexed: 12/22/2022] Open
Abstract
Marine microorganisms are immensely diverse and play fundamental roles in global geochemical cycling. Recent metagenome-assembled genome studies, with particular attention to large-scale projects such as Tara Oceans, have expanded the genomic repertoire of marine microorganisms. However, published marine metagenome data is still underexplored. We collected 2,057 marine metagenomes covering various marine environments and developed a new genome reconstruction pipeline. We reconstructed 52,325 qualified genomes composed of 8,466 prokaryotic species-level clusters spanning 59 phyla, including genomes from the deep-sea characterized as deeper than 1,000 m (n = 3,337), low-oxygen zones of <90 μmol O2 per kg water (n = 7,884), and polar regions (n = 7,752). Novelty evaluation using a genome taxonomy database shows that 6,256 species (73.9%) are novel and include genomes of high taxonomic novelty, such as new class candidates. These genomes collectively expanded the known phylogenetic diversity of marine prokaryotes by 34.2%, and the species representatives cover 26.5–42.0% of prokaryote-enriched metagenomes. Thoroughly leveraging accumulated metagenomic data, this genome resource, named the OceanDNA MAG catalog, illuminates uncharacterized marine microbial ‘dark matter’ lineages. Measurement(s) | microbial community | Technology Type(s) | marine metagenome | Sample Characteristic - Organism | Bacteria • Archaea | Sample Characteristic - Environment | marine biome |
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12
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RNA Viruses in Aquatic Ecosystems through the Lens of Ecological Genomics and Transcriptomics. Viruses 2022; 14:v14040702. [PMID: 35458432 PMCID: PMC9029791 DOI: 10.3390/v14040702] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/19/2022] [Accepted: 03/23/2022] [Indexed: 02/04/2023] Open
Abstract
Massive amounts of data from nucleic acid sequencing have changed our perspective about diversity and dynamics of marine viral communities. Here, we summarize recent metatranscriptomic and metaviromic studies targeting predominantly RNA viral communities. The analysis of RNA viromes reaffirms the abundance of lytic (+) ssRNA viruses of the order Picornavirales, but also reveals other (+) ssRNA viruses, including RNA bacteriophages, as important constituents of extracellular RNA viral communities. Sequencing of dsRNA suggests unknown diversity of dsRNA viruses. Environmental metatranscriptomes capture the dynamics of ssDNA, dsDNA, ssRNA, and dsRNA viruses simultaneously, unravelling the full complexity of viral dynamics in the marine environment. RNA viruses are prevalent in large size fractions of environmental metatranscriptomes, actively infect marine unicellular eukaryotes larger than 3 µm, and can outnumber bacteriophages during phytoplankton blooms. DNA and RNA viruses change abundance on hourly timescales, implying viral control on a daily temporal basis. Metatranscriptomes of cultured protists host a diverse community of ssRNA and dsRNA viruses, often with multipartite genomes and possibly persistent intracellular lifestyles. We posit that RNA viral communities might be more diverse and complex than formerly anticipated and that the influence they exert on community composition and global carbon flows in aquatic ecosystems may be underestimated.
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13
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Albright MBN, Gallegos-Graves LV, Feeser KL, Montoya K, Emerson JB, Shakya M, Dunbar J. Experimental evidence for the impact of soil viruses on carbon cycling during surface plant litter decomposition. ISME COMMUNICATIONS 2022; 2:24. [PMID: 37938672 PMCID: PMC9723558 DOI: 10.1038/s43705-022-00109-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/13/2022] [Accepted: 02/16/2022] [Indexed: 06/01/2023]
Abstract
To date, the potential impact of viral communities on biogeochemical cycles in soil has largely been inferred from correlational evidence, such as virus-driven changes in microbial abundances, viral auxiliary metabolic genes, and links with soil physiochemical properties. To more directly test the impact of soil viruses on carbon cycling during plant litter decomposition, we added concentrated viral community suspensions to complex litter decomposer communities in 40-day microcosm experiments. Microbial communities from two New Mexico alpine soils, Pajarito (PJ) and Santa Fe (SF), were inoculated onto grass litter on sand, and three treatments were applied in triplicate to each set of microcosms: addition of buffer (no added virus), live virus (+virus), or killed-virus (+killed-virus) fractions extracted from the same soil. Significant differences in respiration were observed between the +virus and +killed-virus treatments in the PJ, but not the SF microcosms. Bacterial and fungal community composition differed significantly by treatment in both PJ and SF microcosms. Combining data across both soils, viral addition altered links between bacterial and fungal diversity, dissolved organic carbon and total nitrogen. Overall, we demonstrate that increasing viral pressure in complex microbial communities can impact terrestrial biogeochemical cycling but is context-dependent.
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Affiliation(s)
- Michaeline B N Albright
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, US.
- Allonnia LLC, Boston, MA, US.
| | | | - Kelli L Feeser
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, US
| | - Kyana Montoya
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, US
| | - Joanne B Emerson
- Department of Plant Pathology, University of California, Davis, Davis, CA, US
| | - Migun Shakya
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, US
| | - John Dunbar
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, US
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14
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Intranuclear HSV-1 DNA ejection induces major mechanical transformations suggesting mechanoprotection of nucleus integrity. Proc Natl Acad Sci U S A 2022; 119:2114121119. [PMID: 35197285 PMCID: PMC8892323 DOI: 10.1073/pnas.2114121119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2022] [Indexed: 11/18/2022] Open
Abstract
Maintaining nuclear integrity is essential to cell survival when exposed to mechanical stress. Herpesviruses, like most DNA and some RNA viruses, put strain on the nuclear envelope as hundreds of viral DNA genomes replicate and viral capsids assemble. It remained unknown, however, how nuclear mechanics is affected at the initial stage of herpesvirus infection-immediately after viral genomes are ejected into the nuclear space-and how nucleus integrity is maintained despite an increased strain on the nuclear envelope. With an atomic force microscopy force volume mapping approach on cell-free reconstituted nuclei with docked herpes simplex type 1 (HSV-1) capsids, we explored the mechanical response of the nuclear lamina and the chromatin to intranuclear HSV-1 DNA ejection into an intact nucleus. We discovered that chromatin stiffness, measured as Young's modulus, is increased by ∼14 times, while nuclear lamina underwent softening. Those transformations could be associated with a mechanism of mechanoprotection of nucleus integrity facilitating HSV-1 viral genome replication. Indeed, stiffening of chromatin, which is tethered to the lamina meshwork, helps to maintain nuclear morphology. At the same time, increased lamina elasticity, reflected by nucleus softening, acts as a "shock absorber," dissipating the internal mechanical stress on the nuclear membrane (located on top of the lamina wall) and preventing its rupture.
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15
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Jaskulska A, Šulčius S, Kokociński M, Koreivienė J, Nájera AF, Mankiewicz-Boczek J. Cyanophage Distribution Across European Lakes of the Temperate-Humid Continental Climate Zone Assessed Using PCR-Based Genetic Markers. MICROBIAL ECOLOGY 2022; 83:284-295. [PMID: 34091717 PMCID: PMC8891191 DOI: 10.1007/s00248-021-01783-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/24/2021] [Indexed: 05/16/2023]
Abstract
Studies of the diversity and distribution of freshwater cyanophages are generally limited to the small geographical areas, in many cases including only one or few lakes. Data from dozens of various lakes distributed at a larger distance are necessary to understand their spatial distribution and sensitivity to biotic and abiotic factors. Thus, the objective of this study was to analyze the diversity and distribution of cyanophages within the infected cells using marker genes (psbA, nblA, and g91) in 21 Polish and Lithuanian lakes. Physicochemical factors that might be related to them were also analyzed. The results demonstrated that genetic markers representing cyanophages were observed in most lakes studied. The frequently detected gene was psbA with 88% of cyanophage-positive samples, while nblA and g91 were found in approximately 50% of lakes. The DNA sequence analyses for each gene demonstrated low variability between them, although the psbA sequences branched within the larger cluster of marine Synechoccocuss counterparts. The principal component analysis allowed to identify significant variation between the lakes that presented high and low cyanobacterial biomass. The lakes with high cyanobacterial biomass were further separated by country and the different diversity of cyanobacteria species, particularly Planktothrix agardhii, was dominant in the Polish lakes and Planktolyngbya limnetica in the Lithuanian lakes. The total phosphorous and the presence of cyanophage genes psbA and nblA were the most important factors that allowed differentiation for the Polish lakes, while the pH and the genes g91 and nblA for the Lithuanian lakes.
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Affiliation(s)
- Aleksandra Jaskulska
- UNESCO Chair on Ecohydrology and Applied Ecology, Faculty of Biology and Environmental Protection, University of Łódź, 12/16 Banacha, 90-237 Łódź, Poland
| | - Sigitas Šulčius
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, 2 Akademijos, 08412, Vilnius, Lithuania
| | - Mikołaj Kokociński
- Department of Hydrobiology, Adam Mickiewicz University, 6 Uniwersytetu Poznańskiego, 61-614, Poznań, Poland
| | - Judita Koreivienė
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, 2 Akademijos, 08412, Vilnius, Lithuania
| | - Arnoldo Font Nájera
- UNESCO Chair on Ecohydrology and Applied Ecology, Faculty of Biology and Environmental Protection, University of Łódź, 12/16 Banacha, 90-237 Łódź, Poland
- European Regional Centre for Ecohydrology of the Polish Academy of Sciences, 3 Tylna, 90-364, Łódź, Poland
| | - Joanna Mankiewicz-Boczek
- European Regional Centre for Ecohydrology of the Polish Academy of Sciences, 3 Tylna, 90-364, Łódź, Poland.
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16
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Zhang D, He Y, Gin KYH. Genomic Characterization of a Novel Freshwater Cyanophage Reveals a New Lineage of Cyanopodovirus. Front Microbiol 2022; 12:768868. [PMID: 35095789 PMCID: PMC8790148 DOI: 10.3389/fmicb.2021.768868] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/03/2021] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria are one of the dominant autotrophs in tropical freshwater communities, yet phages infecting them remain poorly characterized. Here we present the characterization of cyanophage S-SRP02, isolated from a tropical freshwater lake in Singapore, which infects Synechococcus sp. Strain SR-C1 isolated from the same lake. S-SRP02 represents a new evolutionary lineage of cyanophage. Out of 47 open reading frames (ORFs), only 20 ORFs share homology with genes encoding proteins of known function. There is lack of auxiliary metabolic genes which was commonly found as core genes in marine cyanopodoviruses. S-SRP02 also harbors unique structural genes highly divergent from other cultured phages. Phylogenetic analysis and viral proteomic tree further demonstrate the divergence of S-SRP02 from other sequenced phage isolates. Nonetheless, S-SRP02 shares synteny with phage genes of uncultured phages obtained from the Mediterranean Sea deep chlorophyll maximum fosmids, indicating the ecological importance of S-SRP02 and its related viruses. This is further supported by metagenomic mapping of environmental viral metagenomic reads onto the S-SRP02 genome.
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Affiliation(s)
- Dong Zhang
- NUS Environmental Research Institute (E2S2-CREATE), National University of Singapore, Singapore, Singapore
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Karina Yew-Hoong Gin
- NUS Environmental Research Institute (E2S2-CREATE), National University of Singapore, Singapore, Singapore.,Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
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17
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Predicting the capsid architecture of phages from metagenomic data. Comput Struct Biotechnol J 2022; 20:721-732. [PMID: 35140890 PMCID: PMC8814770 DOI: 10.1016/j.csbj.2021.12.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 12/29/2022] Open
Abstract
Tailed phages are viruses that infect bacteria and are the most abundant biological entities on Earth. Their ecological, evolutionary, and biogeochemical roles in the planet stem from their genomic diversity. Known tailed phage genomes range from 10 to 735 kilobase pairs thanks to the size variability of the protective protein capsids that store them. However, the role of tailed phage capsids’ diversity in ecosystems is unclear. A fundamental gap is the difficulty of associating genomic information with viral capsids in the environment. To address this problem, here, we introduce a computational approach to predict the capsid architecture (T-number) of tailed phages using the sequence of a single gene—the major capsid protein. This approach relies on an allometric model that relates the genome length and capsid architecture of tailed phages. This allometric model was applied to isolated phage genomes to generate a library that associated major capsid proteins and putative capsid architectures. This library was used to train machine learning methods, and the most computationally scalable model investigated (random forest) was applied to human gut metagenomes. Compared to isolated phages, the analysis of gut data reveals a large abundance of mid-sized (T = 7) capsids, as expected, followed by a relatively large frequency of jumbo-like tailed phage capsids (T ≥ 25) and small capsids (T = 4) that have been under-sampled. We discussed how to increase the method’s accuracy and how to extend the approach to other viruses. The computational pipeline introduced here opens the doors to monitor the ongoing evolution and selection of viral capsids across ecosystems.
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18
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ter Horst AM, Santos-Medellín C, Sorensen JW, Zinke LA, Wilson RM, Johnston ER, Trubl G, Pett-Ridge J, Blazewicz SJ, Hanson PJ, Chanton JP, Schadt CW, Kostka JE, Emerson JB. Minnesota peat viromes reveal terrestrial and aquatic niche partitioning for local and global viral populations. MICROBIOME 2021; 9:233. [PMID: 34836550 PMCID: PMC8626947 DOI: 10.1186/s40168-021-01156-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/02/2021] [Indexed: 05/31/2023]
Abstract
BACKGROUND Peatlands are expected to experience sustained yet fluctuating higher temperatures due to climate change, leading to increased microbial activity and greenhouse gas emissions. Despite mounting evidence for viral contributions to these processes in peatlands underlain with permafrost, little is known about viruses in other peatlands. More generally, soil viral biogeography and its potential drivers are poorly understood at both local and global scales. Here, 87 metagenomes and five viral size-fraction metagenomes (viromes) from a boreal peatland in northern Minnesota (the SPRUCE whole-ecosystem warming experiment and surrounding bog) were analyzed for dsDNA viral community ecological patterns, and the recovered viral populations (vOTUs) were compared with our curated PIGEON database of 266,125 vOTUs from diverse ecosystems. RESULTS Within the SPRUCE experiment, viral community composition was significantly correlated with peat depth, water content, and carbon chemistry, including CH4 and CO2 concentrations, but not with temperature during the first 2 years of warming treatments. Peat vOTUs with aquatic-like signatures (shared predicted protein content with marine and/or freshwater vOTUs) were significantly enriched in more waterlogged surface peat depths. Predicted host ranges for SPRUCE vOTUs were relatively narrow, generally within a single bacterial genus. Of the 4326 SPRUCE vOTUs, 164 were previously detected in other soils, mostly peatlands. None of the previously identified 202,371 marine and freshwater vOTUs in our PIGEON database were detected in SPRUCE peat, but 0.4% of 80,714 viral clusters (VCs, grouped by predicted protein content) were shared between soil and aquatic environments. On a per-sample basis, vOTU recovery was 32 times higher from viromes compared with total metagenomes. CONCLUSIONS Results suggest strong viral "species" boundaries between terrestrial and aquatic ecosystems and to some extent between peat and other soils, with differences less pronounced at higher taxonomic levels. The significant enrichment of aquatic-like vOTUs in more waterlogged peat suggests that viruses may also exhibit niche partitioning on more local scales. These patterns are presumably driven in part by host ecology, consistent with the predicted narrow host ranges. Although more samples and increased sequencing depth improved vOTU recovery from total metagenomes, the substantially higher per-sample vOTU recovery after viral particle enrichment highlights the utility of soil viromics. Video abstract The importance of Minnesota peat viromes in revealing terrestrial and aquatic niche partitioning for viral populations.
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Affiliation(s)
| | | | - Jackson W. Sorensen
- Department of Plant Pathology, University of California, Davis, Davis, CA USA
| | - Laura A. Zinke
- Department of Plant Pathology, University of California, Davis, Davis, CA USA
| | - Rachel M. Wilson
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL USA
| | - Eric R. Johnston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Gareth Trubl
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Steven J. Blazewicz
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Paul J. Hanson
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Jeffrey P. Chanton
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL USA
| | | | - Joel E. Kostka
- Schools of Biology and Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332 USA
| | - Joanne B. Emerson
- Department of Plant Pathology, University of California, Davis, Davis, CA USA
- Genome Center, University of California, Davis, Davis, CA USA
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19
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Long AM, Jurgensen SK, Petchel AR, Savoie ER, Brum JR. Microbial Ecology of Oxygen Minimum Zones Amidst Ocean Deoxygenation. Front Microbiol 2021; 12:748961. [PMID: 34777296 PMCID: PMC8578717 DOI: 10.3389/fmicb.2021.748961] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/06/2021] [Indexed: 01/05/2023] Open
Abstract
Oxygen minimum zones (OMZs) have substantial effects on the global ecology and biogeochemical processes of marine microbes. However, the diversity and activity of OMZ microbes and their trophic interactions are only starting to be documented, especially in regard to the potential roles of viruses and protists. OMZs have expanded over the past 60 years and are predicted to expand due to anthropogenic climate change, furthering the need to understand these regions. This review summarizes the current knowledge of OMZ formation, the biotic and abiotic factors involved in OMZ expansion, and the microbial ecology of OMZs, emphasizing the importance of bacteria, archaea, viruses, and protists. We describe the recognized roles of OMZ microbes in carbon, nitrogen, and sulfur cycling, the potential of viruses in altering host metabolisms involved in these cycles, and the control of microbial populations by grazers and viruses. Further, we highlight the microbial community composition and roles of these organisms in oxic and anoxic depths within the water column and how these differences potentially inform how microbial communities will respond to deoxygenation. Additionally, the current literature on the alteration of microbial communities by other key climate change parameters such as temperature and pH are considered regarding how OMZ microbes might respond to these pressures. Finally, we discuss what knowledge gaps are present in understanding OMZ microbial communities and propose directions that will begin to close these gaps.
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Affiliation(s)
- Andrew M. Long
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, United States
| | | | | | | | - Jennifer R. Brum
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, United States
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20
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Visualizing active viral infection reveals diverse cell fates in synchronized algal bloom demise. Proc Natl Acad Sci U S A 2021; 118:2021586118. [PMID: 33707211 PMCID: PMC7980383 DOI: 10.1073/pnas.2021586118] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Marine viruses are the most abundant biological entity in the ocean and are considered as major evolutionary drivers of microbial life [C. A. Suttle, Nat. Rev. Microbiol. 5, 801-812 (2007)]. Yet, we lack quantitative approaches to assess their impact on the marine ecosystem. Here, we provide quantification of active viral infection in the bloom forming single-celled phytoplankton Emiliania huxleyi infected by the large virus EhV, using high-throughput single-molecule messenger RNA in situ hybridization (smFISH) of both virus and host transcripts. In natural samples, viral infection reached only 25% of the population despite synchronized bloom demise exposing the coexistence of infected and noninfected subpopulations. We prove that photosynthetically active cells chronically release viral particles through nonlytic infection and that viral-induced cell lysis can occur without viral release, thus challenging major assumptions regarding the life cycle of giant viruses. We could also assess active infection in cell aggregates linking viral infection and carbon export to the deep ocean [C. P. Laber et al., Nat. Microbiol. 3, 537-547 (2018)] and suggest a potential host defense strategy by enrichment of infected cells in sinking aggregates. Our approach can be applied to diverse marine microbial systems, opening a mechanistic dimension to the study of biotic interactions in the ocean.
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21
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Wu R, Davison MR, Gao Y, Nicora CD, Mcdermott JE, Burnum-Johnson KE, Hofmockel KS, Jansson JK. Moisture modulates soil reservoirs of active DNA and RNA viruses. Commun Biol 2021; 4:992. [PMID: 34446837 PMCID: PMC8390657 DOI: 10.1038/s42003-021-02514-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 07/18/2021] [Indexed: 02/07/2023] Open
Abstract
Soil is known to harbor viruses, but the majority are uncharacterized and their responses to environmental changes are unknown. Here, we used a multi-omics approach (metagenomics, metatranscriptomics and metaproteomics) to detect active DNA viruses and RNA viruses in a native prairie soil and to determine their responses to extremes in soil moisture. The majority of transcribed DNA viruses were bacteriophage, but some were assigned to eukaryotic hosts, mainly insects. We also demonstrated that higher soil moisture increased transcription of a subset of DNA viruses. Metaproteome data validated that the specific viral transcripts were translated into proteins, including chaperonins known to be essential for virion replication and assembly. The soil viral chaperonins were phylogenetically distinct from previously described marine viral chaperonins. The soil also had a high abundance of RNA viruses, with highest representation of Reoviridae. Leviviridae were the most diverse RNA viruses in the samples, with higher amounts in wet soil. This study demonstrates that extreme shifts in soil moisture have dramatic impacts on the composition, activity and potential functions of both DNA and RNA soil viruses.
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Affiliation(s)
- Ruonan Wu
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Michelle R Davison
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Yuqian Gao
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Carrie D Nicora
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Jason E Mcdermott
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Kristin E Burnum-Johnson
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Kirsten S Hofmockel
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
- Department of Agronomy, Iowa State University, Ames, IA, USA
| | - Janet K Jansson
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA.
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22
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Savoie ER, Lanclos VC, Henson MW, Cheng C, Getz EW, Barnes SJ, LaRowe DE, Rappé MS, Thrash JC. Ecophysiology of the Cosmopolitan OM252 Bacterioplankton ( Gammaproteobacteria). mSystems 2021; 6:e0027621. [PMID: 34184914 PMCID: PMC8269220 DOI: 10.1128/msystems.00276-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/26/2021] [Indexed: 12/27/2022] Open
Abstract
Among the thousands of species that comprise marine bacterioplankton communities, most remain functionally obscure. One key cosmopolitan group in this understudied majority is the OM252 clade of Gammaproteobacteria. Although frequently found in sequence data and even previously cultured, the diversity, metabolic potential, physiology, and distribution of this clade has not been thoroughly investigated. Here, we examined these features of OM252 bacterioplankton using a newly isolated strain and genomes from publicly available databases. We demonstrated that this group constitutes a globally distributed novel genus ("Candidatus Halomarinus"), sister to Litoricola, comprising two subclades and multiple distinct species. OM252 organisms have small genomes (median, 2.21 Mbp) and are predicted obligate aerobes capable of alternating between chemoorganoheterotrophic and chemolithotrophic growth using reduced sulfur compounds as electron donors. Subclade I genomes encode genes for the Calvin-Benson-Bassham cycle for carbon fixation. One representative strain of subclade I, LSUCC0096, had extensive halotolerance and a mesophilic temperature range for growth, with a maximum rate of 0.36 doublings/h at 35°C. Cells were curved rod/spirillum-shaped, ∼1.5 by 0.2 μm. Growth yield on thiosulfate as the sole electron donor under autotrophic conditions was roughly one-third that of heterotrophic growth, even though calculations indicated similar Gibbs energies for both catabolisms. These phenotypic data show that some "Ca. Halomarinus" organisms can switch between serving as carbon sources or sinks and indicate the likely anabolic cost of lithoautotrophic growth. Our results thus provide new hypotheses about the roles of these organisms in global biogeochemical cycling of carbon and sulfur. IMPORTANCE Marine microbial communities are teeming with understudied taxa due to the sheer numbers of species in any given sample of seawater. One group, the OM252 clade of Gammaproteobacteria, has been identified in gene surveys from myriad locations, and one isolated organism has even been genome sequenced (HIMB30). However, further study of these organisms has not occurred. Using another isolated representative (strain LSUCC0096) and publicly available genome sequences from metagenomic and single-cell genomic data sets, we examined the diversity within the OM252 clade and the distribution of these taxa in the world's oceans, reconstructed the predicted metabolism of the group, and quantified growth dynamics in LSUCC0096. Our results generate new knowledge about the previously enigmatic OM252 clade and point toward the importance of facultative chemolithoautotrophy for supporting some clades of ostensibly "heterotrophic" taxa.
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Affiliation(s)
- Emily R. Savoie
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - V. Celeste Lanclos
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Michael W. Henson
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Chuankai Cheng
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Eric W. Getz
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Shelby J. Barnes
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Douglas E. LaRowe
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - Michael S. Rappé
- Hawai’i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawaiʻi at Mānoa, Kāneʻohe, Hawaii, USA
| | - J. Cameron Thrash
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
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23
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Townsend EM, Kelly L, Muscatt G, Box JD, Hargraves N, Lilley D, Jameson E. The Human Gut Phageome: Origins and Roles in the Human Gut Microbiome. Front Cell Infect Microbiol 2021; 11:643214. [PMID: 34150671 PMCID: PMC8213399 DOI: 10.3389/fcimb.2021.643214] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/19/2021] [Indexed: 12/14/2022] Open
Abstract
The investigation of the microbial populations of the human body, known as the microbiome, has led to a revolutionary field of science, and understanding of its impacts on human development and health. The majority of microbiome research to date has focussed on bacteria and other kingdoms of life, such as fungi. Trailing behind these is the interrogation of the gut viruses, specifically the phageome. Bacteriophages, viruses that infect bacterial hosts, are known to dictate the dynamics and diversity of bacterial populations in a number of ecosystems. However, the phageome of the human gut, while of apparent importance, remains an area of many unknowns. In this paper we discuss the role of bacteriophages within the human gut microbiome. We examine the methods used to study bacteriophage populations, how this evolved over time and what we now understand about the phageome. We review the phageome development in infancy, and factors that may influence phage populations in adult life. The role and action of the phageome is then discussed at both a biological-level, and in the broader context of human health and disease.
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Affiliation(s)
- Eleanor M Townsend
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Lucy Kelly
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - George Muscatt
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Joshua D Box
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Nicole Hargraves
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Daniel Lilley
- Warwick Medical School, The University of Warwick, Coventry, United Kingdom
| | - Eleanor Jameson
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
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24
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Host population diversity as a driver of viral infection cycle in wild populations of green sulfur bacteria with long standing virus-host interactions. THE ISME JOURNAL 2021; 15:1569-1584. [PMID: 33452481 PMCID: PMC8163819 DOI: 10.1038/s41396-020-00870-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 09/29/2020] [Accepted: 12/07/2020] [Indexed: 01/29/2023]
Abstract
Temperate phages are viruses of bacteria that can establish two types of infection: a lysogenic infection in which the virus replicates with the host cell without producing virions, and a lytic infection where the host cell is eventually destroyed, and new virions are released. While both lytic and lysogenic infections are routinely observed in the environment, the ecological and evolutionary processes regulating these viral dynamics are still not well understood, especially for uncultivated virus-host pairs. Here, we characterized the long-term dynamics of uncultivated viruses infecting green sulfur bacteria (GSB) in a model freshwater lake (Trout Bog Lake, TBL). As no GSB virus has been formally described yet, we first used two complementary approaches to identify new GSB viruses from TBL; one in vitro based on flow cytometry cell sorting, the other in silico based on CRISPR spacer sequences. We then took advantage of existing TBL metagenomes covering the 2005-2018 period to examine the interactions between GSB and their viruses across years and seasons. From our data, GSB populations in TBL were constantly associated with at least 2-8 viruses each, including both lytic and temperate phages. The dominant GSB population in particular was consistently associated with two prophages with a nearly 100% infection rate for >10 years. We illustrate with a theoretical model that such an interaction can be stable given a low, but persistent, level of prophage induction in low-diversity host populations. Overall, our data suggest that lytic and lysogenic viruses can readily co-infect the same host population, and that host strain-level diversity might be an important factor controlling virus-host dynamics including lytic/lysogeny switch.
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25
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Braga LPP, Coutinho FH, Amgarten DE, Kot W, Hansen L, Setubal JC, Philippot L. Novel virocell metabolic potential revealed in agricultural soils by virus-enriched soil metagenome analysis. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:348-354. [PMID: 34018688 DOI: 10.1111/1758-2229.12939] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/28/2020] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
Viruses are now recognized as important players in microbial dynamics and biogeochemical cycles in the oceans. Yet, compared with aquatic ecosystems, virus discovery in terrestrial ecosystems has been challenging partly due to the inherent complexity of soils. To expand our understanding of soil viruses and their putative contributions to soil microbial processes, we analysed metagenomes of community-level virus-enriched suspensions by tangential flow filtration obtained from two French agricultural soils. We found viral sequences representing a total of 239 viral operational taxonomic units that corresponded to 29.5% of the mapping reads in the metagenomic datasets. The analysis of their genomic sequences revealed novel virocell metabolic potential with implications to virus-host interactions, carbon cycling, plant-beneficial functions in the rhizosphere, horizontal gene transfer and other relevant microbial strategies applied to survive in soils.
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Affiliation(s)
- Lucas P P Braga
- University of Burgundy Franche-Comté, INRAE, AgroSup Dijon, Agroécologie Department, Dijon, France
- Institute of Chemistry, University of São Paulo, São Paulo, Brazil
- Ecosystems and Global Change Group, Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Felipe H Coutinho
- Evolutionary Genomics Group, Universidad Miguel Henández, Alicante, Spain
| | | | - Witold Kot
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lars Hansen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - João C Setubal
- Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Laurent Philippot
- University of Burgundy Franche-Comté, INRAE, AgroSup Dijon, Agroécologie Department, Dijon, France
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26
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Evaluating and Improving Small Subunit rRNA PCR Primer Coverage for Bacteria, Archaea, and Eukaryotes Using Metagenomes from Global Ocean Surveys. mSystems 2021; 6:e0056521. [PMID: 34060911 PMCID: PMC8269242 DOI: 10.1128/msystems.00565-21] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Small subunit rRNA (SSU rRNA) amplicon sequencing can quantitatively and comprehensively profile natural microbiomes, representing a critically important tool for studying diverse global ecosystems. However, results will only be accurate if PCR primers perfectly match the rRNA of all organisms present. To evaluate how well marine microorganisms across all 3 domains are detected by this method, we compared commonly used primers with >300 million rRNA gene sequences retrieved from globally distributed marine metagenomes. The best-performing primers compared to 16S rRNA of bacteria and archaea were 515Y/926R and 515Y/806RB, which perfectly matched over 96% of all sequences. Considering cyanobacterial and chloroplast 16S rRNA, 515Y/926R had the highest coverage (99%), making this set ideal for quantifying marine primary producers. For eukaryotic 18S rRNA sequences, 515Y/926R also performed best (88%), followed by V4R/V4RB (18S rRNA specific; 82%)-demonstrating that the 515Y/926R combination performs best overall for all 3 domains. Using Atlantic and Pacific Ocean samples, we demonstrate high correspondence between 515Y/926R amplicon abundances (generated for this study) and metagenomic 16S rRNA (median R2 = 0.98, n = 272), indicating amplicons can produce equally accurate community composition data compared with shotgun metagenomics. Our analysis also revealed that expected performance of all primer sets could be improved with minor modifications, pointing toward a nearly completely universal primer set that could accurately quantify biogeochemically important taxa in ecosystems ranging from the deep sea to the surface. In addition, our reproducible bioinformatic workflow can guide microbiome researchers studying different ecosystems or human health to similarly improve existing primers and generate more accurate quantitative amplicon data. IMPORTANCE PCR amplification and sequencing of marker genes is a low-cost technique for monitoring prokaryotic and eukaryotic microbial communities across space and time but will work optimally only if environmental organisms match PCR primer sequences exactly. In this study, we evaluated how well primers match globally distributed short-read oceanic metagenomes. Our results demonstrate that primer sets vary widely in performance, and that at least for marine systems, rRNA amplicon data from some primers lack significant biases compared to metagenomes. We also show that it is theoretically possible to create a nearly universal primer set for diverse saline environments by defining a specific mixture of a few dozen oligonucleotides, and present a software pipeline that can guide rational design of primers for any environment with available meta'omic data.
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27
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Sommers P, Chatterjee A, Varsani A, Trubl G. Integrating Viral Metagenomics into an Ecological Framework. Annu Rev Virol 2021; 8:133-158. [PMID: 34033501 DOI: 10.1146/annurev-virology-010421-053015] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viral metagenomics has expanded our knowledge of the ecology of uncultured viruses, within both environmental (e.g., terrestrial and aquatic) and host-associated (e.g., plants and animals, including humans) contexts. Here, we emphasize the implementation of an ecological framework in viral metagenomic studies to address questions in virology rarely considered ecological, which can change our perception of viruses and how they interact with their surroundings. An ecological framework explicitly considers diverse variants of viruses in populations that make up communities of interacting viruses, with ecosystem-level effects. It provides a structure for the study of the diversity, distributions, dynamics, and interactions of viruses with one another, hosts, and the ecosystem, including interactions with abiotic factors. An ecological framework in viral metagenomics stands poised to broadly expand our knowledge in basic and applied virology. We highlight specific fundamental research needs to capitalize on its potential and advance the field. Expected final online publication date for the Annual Review of Virology, Volume 8 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Pacifica Sommers
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA.,These authors contributed equally to this article
| | - Anushila Chatterjee
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA.,These authors contributed equally to this article
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, Arizona 85287, USA; .,Structural Biology Research Unit, Department of Integrative Biomedical Sciences, University of Cape Town, Observatory 7925, South Africa
| | - Gareth Trubl
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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28
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Vallino M, Rossi M, Ottati S, Martino G, Galetto L, Marzachì C, Abbà S. Bacteriophage-Host Association in the Phytoplasma Insect Vector Euscelidius variegatus. Pathogens 2021; 10:pathogens10050612. [PMID: 34067814 PMCID: PMC8156552 DOI: 10.3390/pathogens10050612] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 12/26/2022] Open
Abstract
Insect vectors transmit viruses and bacteria that can cause severe diseases in plants and economic losses due to a decrease in crop production. Insect vectors, like all other organisms, are colonized by a community of various microorganisms, which can influence their physiology, ecology, evolution, and also their competence as vectors. The important ecological meaning of bacteriophages in various ecosystems and their role in microbial communities has emerged in the past decade. However, only a few phages have been described so far in insect microbiomes. The leafhopper Euscelidius variegatus is a laboratory vector of the phytoplasma causing Flavescence dorée, a severe grapevine disease that threatens viticulture in Europe. Here, the presence of a temperate bacteriophage in E. variegatus (named Euscelidius variegatus phage 1, EVP-1) was revealed through both insect transcriptome analyses and electron microscopic observations. The bacterial host was isolated in axenic culture and identified as the bacterial endosymbiont of E. variegatus (BEV), recently assigned to the genus Candidatus Symbiopectobacterium. BEV harbors multiple prophages that become active in culture, suggesting that different environments can trigger different mechanisms, finely regulating the interactions among phages. Understanding the complex relationships within insect vector microbiomes may help in revealing possible microbe influences on pathogen transmission, and it is a crucial step toward innovative sustainable strategies for disease management in agriculture.
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Affiliation(s)
- Marta Vallino
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (S.O.); (G.M.); (L.G.); (C.M.); (S.A.)
- Correspondence:
| | - Marika Rossi
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (S.O.); (G.M.); (L.G.); (C.M.); (S.A.)
| | - Sara Ottati
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (S.O.); (G.M.); (L.G.); (C.M.); (S.A.)
- Dipartimento di Scienze Agrarie, Forestali ed Alimentari DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
| | - Gabriele Martino
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (S.O.); (G.M.); (L.G.); (C.M.); (S.A.)
- Dipartimento di Scienze Agrarie, Forestali ed Alimentari DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
| | - Luciana Galetto
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (S.O.); (G.M.); (L.G.); (C.M.); (S.A.)
| | - Cristina Marzachì
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (S.O.); (G.M.); (L.G.); (C.M.); (S.A.)
| | - Simona Abbà
- Institute for Sustainable Plant Protection, National Research Council of Italy, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (S.O.); (G.M.); (L.G.); (C.M.); (S.A.)
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29
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Interaction dynamics and virus-host range for estuarine actinophages captured by epicPCR. Nat Microbiol 2021; 6:630-642. [PMID: 33633401 DOI: 10.1038/s41564-021-00873-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 01/28/2021] [Indexed: 01/31/2023]
Abstract
Viruses impact microbial diversity, gene flow and function through virus-host interactions. Although metagenomics surveys are rapidly cataloguing viral diversity, methods are needed to capture specific virus-host interactions in situ. Here, we leveraged metagenomics and repurposed emulsion paired isolation-concatenation PCR (epicPCR) to investigate viral diversity and virus-host interactions in situ over time in an estuarine environment. The method fuses a phage marker, the ribonucleotide reductase gene, with the host 16S rRNA gene of infected bacterial cells within emulsion droplets providing single-cell resolution for dozens of samples. EpicPCR captured in situ virus-host interactions for viral clades with no closely related database representatives. Abundant freshwater Actinobacteria lineages, in particular Rhodoluna sp., were the most common hosts for these poorly characterized viruses, with interactions correlated with environmental factors. Multiple methods used to identify virus-host interactions, including epicPCR, identified different and largely non-overlapping interactions within the vast virus-host interaction space. Tracking virus-host interaction dynamics also revealed that multi-host viruses had significantly longer periods with observed virus-host interactions, whereas single-host viruses were observed interacting with hosts at lower minimum abundances, suggesting more efficient interactions. Capturing in situ interactions with epicPCR revealed environmental and ecological factors shaping virus-host interactions, highlighting epicPCR as a valuable technique in viral ecology.
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30
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Abstract
Viruses are ubiquitous and abundant in the oceans, and viral metagenomes (viromes) have been investigated extensively via several large-scale ocean sequencing projects. However, there have not been any systematic viromic studies in estuaries. Here, we investigated the viromes of the Delaware Bay and Chesapeake Bay, two Mid-Atlantic estuaries. Deep sequencing generated a total of 48,190 assembled viral sequences (>5 kb) and 26,487 viral populations (9,204 virus clusters and 17,845 singletons), including 319 circular viral contigs between 7.5 kb and 161.8 kb. Unknown viruses represented the vast majority of the dominant populations, while the composition of known viruses, such as pelagiphage and cyanophage, appeared to be relatively consistent across a wide range of salinity gradients and in different seasons. A difference between estuarine and ocean viromes was reflected by the proportions of Myoviridae, Podoviridae, Siphoviridae, Phycodnaviridae, and a few well-studied virus representatives. The difference in viral community between the Delaware Bay and Chesapeake Bay is significantly more pronounced than the difference caused by temperature or salinity, indicating strong local profiles caused by the unique ecology of each estuary. Interestingly, a viral contig similar to phages infecting Acinetobacter baumannii (“Iraqibacter”) was found to be highly abundant in the Delaware Bay but not in the Chesapeake Bay, the source of which is yet to be identified. Highly abundant viruses in both estuaries have close hits to viral sequences derived from the marine single-cell genomes or long-read single-molecule sequencing, suggesting that important viruses are still waiting to be discovered in the estuarine environment. IMPORTANCE This is the first systematic study about spatial and temporal variation of virioplankton communities in estuaries using deep metagenomics sequencing. It is among the highest-quality viromic data sets to date, showing remarkably consistent sequencing depth and quality across samples. Our results indicate that there exists a large pool of abundant and diverse viruses in estuaries that have not yet been cultivated, their genomes only available thanks to single-cell genomics or single-molecule sequencing, demonstrating the importance of these methods for viral discovery. The spatiotemporal pattern of these abundant uncultivated viruses is more variable than that of cultured viruses. Despite strong environmental gradients, season and location had surprisingly little impact on the viral community within an estuary, but we saw a significant distinction between the two estuaries and also between estuarine and open ocean viromes.
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31
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Seasonal and diel patterns of abundance and activity of viruses in the Red Sea. Proc Natl Acad Sci U S A 2020; 117:29738-29747. [PMID: 33172994 DOI: 10.1073/pnas.2010783117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Virus-microbe interactions have been studied in great molecular details for many years in cultured model systems, yielding a plethora of knowledge on how viruses use and manipulate host machinery. Since the advent of molecular techniques and high-throughput sequencing, methods such as cooccurrence, nucleotide composition, and other statistical frameworks have been widely used to infer virus-microbe interactions, overcoming the limitations of culturing methods. However, their accuracy and relevance is still debatable as cooccurrence does not necessarily mean interaction. Here we introduce an ecological perspective of marine viral communities and potential interaction with their hosts, using analyses that make no prior assumptions on specific virus-host pairs. By size fractionating water samples into free viruses and microbes (i.e., also viruses inside or attached to their hosts) and looking at how viral group abundance changes over time along both fractions, we show that the viral community is undergoing a change in rank abundance across seasons, suggesting a seasonal succession of viruses in the Red Sea. We use abundance patterns in the different size fractions to classify viral clusters, indicating potential diverse interactions with their hosts and potential differences in life history traits between major viral groups. Finally, we show hourly resolved variations of intracellular abundance of similar viral groups, which might indicate differences in their infection cycles or metabolic capacities.
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32
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Predetermined clockwork microbial worlds: Current understanding of aquatic microbial diel response from model systems to complex environments. ADVANCES IN APPLIED MICROBIOLOGY 2020; 113:163-191. [PMID: 32948266 DOI: 10.1016/bs.aambs.2020.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In the photic zone of aquatic ecosystems, microorganisms with different metabolisms and their viruses form complex interactions and food webs. Within these interactions, phototrophic microorganisms such as eukaryotic microalgae and cyanobacteria interact directly with sunlight, and thereby generate circadian rhythms. Diel cycling originally generated in microbial phototrophs is directly transmitted toward heterotrophic microorganisms utilizing the photosynthetic products as they are excreted or exuded. Such diel cycling seems to be indirectly propagated toward heterotrophs as a result of complex biotic interactions. For example, cell death of phototrophic microorganisms induced by viral lysis and protistan grazing provides additional resources of dissolved organic matter to the microbial community, and so generates diel cycling in other heterotrophs with different nutrient dependencies. Likewise, differences in the diel transmitting pathway via complex interactions among heterotrophs, and between heterotrophs and their viruses, may also generate higher variation and time lag diel rhythms in different heterotrophic taxa. Thus, sunlight and photosynthesis not only contribute energy and carbon supply, but also directly or indirectly control diel cycling of the microbial community through complex interactions in the photic zone of aquatic ecosystems.
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33
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Wang M, Gao C, Jiang T, You S, Jiang Y, Guo C, He H, Liu Y, Zhang X, Shao H, Liu H, Liang Y, Wang M, McMinn A. Genomic analysis of Synechococcus phage S-B43 and its adaption to the coastal environment. Virus Res 2020; 289:198155. [PMID: 32941942 DOI: 10.1016/j.virusres.2020.198155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 11/17/2022]
Abstract
Synechococcus dominate picocyanobacterial communities in coastal environments. However, only a few Synechococcus phages have been described from the coastal seas of the Northwest Pacific Ocean. Here a new Synechococcus phage, S-B43 was isolated from the Bohai Sea, a semi-closed coastal sea of the Northwest Pacific Ocean. S-B43 is a member of Myoviridae, containing 275 predicted open reading frames. Fourteen auxiliary metabolic genes (AMG) were identified from the genome of S-B43, including five photosynthetic associated genes and several AMGs related to its adaption to the high turbidity and eutrophic coastal environment with a low ratio of phosphorus to nitrogen (HNLP). The occurrences of 31 AMGs among 34 cyanophage genomes indicates that AMGs zwf, gnd, speD, petF and those coding for FECH and thioredoxin were more common in coastal areas than in the open ocean and AMGs pebS and ho1 were more prevalent in the open ocean. The occurrence of cyanophage AMGs in different environments might be a reflection of the environmental adaption of their hosts. This study contributes to our understanding of the interactions between cyanobacteria and cyanophages and their environmental adaption to the coastal environment.
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Affiliation(s)
- Meiwen Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Chen Gao
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Tong Jiang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Siyuan You
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yong Jiang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Cui Guo
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Hui He
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yundan Liu
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Xinran Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Hongbing Shao
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
| | - Hongbin Liu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Yantao Liang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
| | - Min Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Andrew McMinn
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7001, Australia
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34
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Shapiro JW, Putonti C. UPΦ phages, a new group of filamentous phages found in several members of Enterobacteriales. Virus Evol 2020; 6:veaa030. [PMID: 32607251 PMCID: PMC7307601 DOI: 10.1093/ve/veaa030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Filamentous phages establish chronic infections in their bacterial hosts, and new phages are secreted by infected bacteria for multiple generations, typically without causing host death. Often, these viruses integrate in their host's genome by co-opting the host's XerCD recombinase system. In several cases, these viruses also encode genes that increase bacterial virulence in plants and animals. Here, we describe a new filamentous phage, UPϕ901, which we originally found integrated in a clinical isolate of Escherichia coli from urine. UPϕ901 and closely related phages can be found in published genomes of over 200 other bacteria, including strains of Citrobacter koseri, Salmonella enterica, Yersinia enterocolitica, and Klebsiella pneumoniae. Its closest relatives are consistently found in urine or in the blood and feces of patients with urinary tract infections. More distant relatives can be found in isolates from other environments, including sewage, water, soil, and contaminated food. Each of these phages, which we collectively call 'UPϕ viruses', also harbors two or more novel genes of unknown function.
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Affiliation(s)
- Jason W Shapiro
- Department of Biology, Loyola University Chicago, 1032 W Sheridan Rd, Chicago, IL 60660, USA
| | - Catherine Putonti
- Department of Biology, Loyola University Chicago, 1032 W Sheridan Rd, Chicago, IL 60660, USA.,Department of Computer Science, Loyola University Chicago, 1052 W Loyola Ave, Chicago, IL, 60626, USA.,Bioinformatics Program, Loyola University Chicago, 1052 W Loyola Ave, Chicago, IL 60626, USA.,Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, 2160 S First Ave, Maywood, IL 60153, USA
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35
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Campbell IJ, Olmos JL, Xu W, Kahanda D, Atkinson JT, Sparks ON, Miller MD, Phillips GN, Bennett GN, Silberg JJ. Prochlorococcus phage ferredoxin: structural characterization and electron transfer to cyanobacterial sulfite reductases. J Biol Chem 2020; 295:10610-10623. [PMID: 32434930 DOI: 10.1074/jbc.ra120.013501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/15/2020] [Indexed: 01/13/2023] Open
Abstract
Marine cyanobacteria are infected by phages whose genomes encode ferredoxin (Fd) electron carriers. These Fds are thought to redirect the energy harvested from light to phage-encoded oxidoreductases that enhance viral fitness, but it is unclear how the biophysical properties and partner specificities of phage Fds relate to those of photosynthetic organisms. Here, results of a bioinformatics analysis using a sequence similarity network revealed that phage Fds are most closely related to cyanobacterial Fds that transfer electrons from photosystems to oxidoreductases involved in nutrient assimilation. Structural analysis of myovirus P-SSM2 Fd (pssm2-Fd), which infects the cyanobacterium Prochlorococcus marinus, revealed high levels of similarity to cyanobacterial Fds (root mean square deviations of ≤0.5 Å). Additionally, pssm2-Fd exhibited a low midpoint reduction potential (-336 mV versus a standard hydrogen electrode), similar to other photosynthetic Fds, although it had lower thermostability (Tm = 28 °C) than did many other Fds. When expressed in an Escherichia coli strain deficient in sulfite assimilation, pssm2-Fd complemented bacterial growth when coexpressed with a P. marinus sulfite reductase, revealing that pssm2-Fd can transfer electrons to a host protein involved in nutrient assimilation. The high levels of structural similarity with cyanobacterial Fds and reactivity with a host sulfite reductase suggest that phage Fds evolved to transfer electrons to cyanobacterially encoded oxidoreductases.
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Affiliation(s)
- Ian J Campbell
- Biochemistry and Cell Biology Graduate Program, Rice University, Houston, Texas, USA.,Department of Biosciences, Rice University, Houston, Texas, USA
| | - Jose Luis Olmos
- Biochemistry and Cell Biology Graduate Program, Rice University, Houston, Texas, USA.,Department of Biosciences, Rice University, Houston, Texas, USA
| | - Weijun Xu
- Department of Biosciences, Rice University, Houston, Texas, USA
| | | | | | | | | | - George N Phillips
- Department of Biosciences, Rice University, Houston, Texas, USA.,Department of Chemistry, Rice University, Houston, Texas, USA
| | - George N Bennett
- Department of Biosciences, Rice University, Houston, Texas, USA.,Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas, USA
| | - Jonathan J Silberg
- Department of Biosciences, Rice University, Houston, Texas, USA .,Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas, USA.,Department of Bioengineering, Rice University, Houston, Texas, USA
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36
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Luo E, Eppley JM, Romano AE, Mende DR, DeLong EF. Double-stranded DNA virioplankton dynamics and reproductive strategies in the oligotrophic open ocean water column. THE ISME JOURNAL 2020; 14:1304-1315. [PMID: 32060418 PMCID: PMC7174320 DOI: 10.1038/s41396-020-0604-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/17/2019] [Accepted: 01/30/2020] [Indexed: 12/11/2022]
Abstract
Microbial communities are critical to ecosystem dynamics and biogeochemical cycling in the open oceans. Viruses are essential elements of these communities, influencing the productivity, diversity, and evolution of cellular hosts. To further explore the natural history and ecology of open-ocean viruses, we surveyed the spatiotemporal dynamics of double-stranded DNA (dsDNA) viruses in both virioplankton and bacterioplankton size fractions in the North Pacific Subtropical Gyre, one of the largest biomes on the planet. Assembly and clustering of viral genomes revealed a peak in virioplankton diversity at the base of the euphotic zone, where virus populations and host species richness both reached their maxima. Simultaneous characterization of both extracellular and intracellular viruses suggested depth-specific reproductive strategies. In particular, analyses indicated elevated lytic interactions in the mixed layer, more temporally variable temperate phage interactions at the base of the euphotic zone, and increased lysogeny in the mesopelagic ocean. Furthermore, the depth variability of auxiliary metabolic genes suggested habitat-specific strategies for viral influence on light-energy, nitrogen, and phosphorus acquisition during host infection. Most virus populations were temporally persistent over several years in this environment at the 95% nucleic acid identity level. In total, our analyses revealed variable distributional patterns and diverse reproductive and metabolic strategies of virus populations in the open-ocean water column.
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Affiliation(s)
- Elaine Luo
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - John M Eppley
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - Anna E Romano
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - Daniel R Mende
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - Edward F DeLong
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA.
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37
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Coming-of-Age Characterization of Soil Viruses: A User’s Guide to Virus Isolation, Detection within Metagenomes, and Viromics. SOIL SYSTEMS 2020. [DOI: 10.3390/soilsystems4020023] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The study of soil viruses, though not new, has languished relative to the study of marine viruses. This is particularly due to challenges associated with separating virions from harboring soils. Generally, three approaches to analyzing soil viruses have been employed: (1) Isolation, to characterize virus genotypes and phenotypes, the primary method used prior to the start of the 21st century. (2) Metagenomics, which has revealed a vast diversity of viruses while also allowing insights into viral community ecology, although with limitations due to DNA from cellular organisms obscuring viral DNA. (3) Viromics (targeted metagenomics of virus-like-particles), which has provided a more focused development of ‘virus-sequence-to-ecology’ pipelines, a result of separation of presumptive virions from cellular organisms prior to DNA extraction. This separation permits greater sequencing emphasis on virus DNA and thereby more targeted molecular and ecological characterization of viruses. Employing viromics to characterize soil systems presents new challenges, however. Ones that only recently are being addressed. Here we provide a guide to implementing these three approaches to studying environmental viruses, highlighting benefits, difficulties, and potential contamination, all toward fostering greater focus on viruses in the study of soil ecology.
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38
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Ignacio-Espinoza JC, Ahlgren NA, Fuhrman JA. Long-term stability and Red Queen-like strain dynamics in marine viruses. Nat Microbiol 2019; 5:265-271. [PMID: 31819214 DOI: 10.1038/s41564-019-0628-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 11/04/2019] [Indexed: 11/09/2022]
Abstract
Viruses that infect microorganisms dominate marine microbial communities numerically, with impacts ranging from host evolution to global biogeochemical cycles1,2. However, virus community dynamics, necessary for conceptual and mechanistic model development, remains difficult to assess. Here, we describe the long-term stability of a viral community by analysing the metagenomes of near-surface 0.02-0.2 μm samples from the San Pedro Ocean Time-series3 that were sampled monthly over 5 years. Of 19,907 assembled viral contigs (>5 kb, mean 15 kb), 97% were found in each sample (by >98% ID metagenomic read recruitment) to have relative abundances that ranged over seven orders of magnitude, with limited temporal reordering of rank abundances along with little change in richness. Seasonal variations in viral community composition were superimposed on the overall stability; maximum community similarity occurred at 12-month intervals. Despite the stability of viral genotypic clusters that had 98% sequence identity, viral sequences showed transient variations in single-nucleotide polymorphisms (SNPs) and constant turnover of minor population variants, each rising and falling over a few months, reminiscent of Red Queen dynamics4. The rise and fall of variants within populations, interpreted through the perspective of known virus-host interactions5, is consistent with the hypothesis that fluctuating selection acts on a microdiverse cloud of strains, and this succession is associated with ever-shifting virus-host defences and counterdefences. This results in long-term virus-host coexistence that is facilitated by perpetually changing minor variants.
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Affiliation(s)
| | - Nathan A Ahlgren
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.,Department of Biology, Clark University, Worcester, MA, USA
| | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.
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39
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Zimmerman AE, Howard-Varona C, Needham DM, John SG, Worden AZ, Sullivan MB, Waldbauer JR, Coleman ML. Metabolic and biogeochemical consequences of viral infection in aquatic ecosystems. Nat Rev Microbiol 2019; 18:21-34. [PMID: 31690825 DOI: 10.1038/s41579-019-0270-x] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2019] [Indexed: 12/23/2022]
Abstract
Ecosystems are controlled by 'bottom-up' (resources) and 'top-down' (predation) forces. Viral infection is now recognized as a ubiquitous top-down control of microbial growth across ecosystems but, at the same time, cell death by viral predation influences, and is influenced by, resource availability. In this Review, we discuss recent advances in understanding the biogeochemical impact of viruses, focusing on how metabolic reprogramming of host cells during lytic viral infection alters the flow of energy and nutrients in aquatic ecosystems. Our synthesis revealed several emerging themes. First, viral infection transforms host metabolism, in part through virus-encoded metabolic genes; the functions performed by these genes appear to alleviate energetic and biosynthetic bottlenecks to viral production. Second, viral infection depends on the physiological state of the host cell and on environmental conditions, which are challenging to replicate in the laboratory. Last, metabolic reprogramming of infected cells and viral lysis alter nutrient cycling and carbon export in the oceans, although the net impacts remain uncertain. This Review highlights the need for understanding viral infection dynamics in realistic physiological and environmental contexts to better predict their biogeochemical consequences.
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Affiliation(s)
- Amy E Zimmerman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA
| | | | - David M Needham
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Seth G John
- Department of Earth Science, University of Southern California, Los Angeles, CA, USA
| | - Alexandra Z Worden
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA.,Ocean EcoSystems Biology Unit, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Matthew B Sullivan
- Department of Microbiology, Ohio State University, Columbus, OH, USA.,Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, USA
| | - Jacob R Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA
| | - Maureen L Coleman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA.
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40
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Bonetti G, Trevathan-Tackett SM, Carnell PE, Macreadie PI. Implication of Viral Infections for Greenhouse Gas Dynamics in Freshwater Wetlands: Challenges and Perspectives. Front Microbiol 2019; 10:1962. [PMID: 31507569 PMCID: PMC6718870 DOI: 10.3389/fmicb.2019.01962] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 08/09/2019] [Indexed: 01/07/2023] Open
Abstract
Viruses are non-living, acellular entities, and the most abundant biological agents on earth. They are widely acknowledged as having the capacity to influence global biogeochemical cycles by infecting the bacterial and archaeal populations that regulate carbon and nutrient turnover. Evidence suggests that the majority of viruses in wetlands are bacteriophages, but despite their importance, studies on how viruses control the prokaryotic community and the concomitant impacts on ecosystem function (such as carbon cycling and greenhouse gas flux) in wetlands are rare. Here we investigate virus-prokaryote interactions in freshwater wetland ecosystems in the context of their potential influence on biogeochemical cycling. Specifically, we (1) synthesize existing literature to establish current understanding of virus-prokaryote interactions, focusing on the implications for wetland greenhouse gas dynamics and (2) identify future research priorities. Viral dynamics in freshwater wetlands have received much less attention compared to those in marine ecosystems. However, based on our literature review, within the last 10 years, viral ecology studies on freshwater wetlands have increased twofold. Despite this increase in literature, the potential implication of viral infections on greenhouse gas emission dynamics is still a knowledge gap. We hypothesize that the rate of greenhouse gas emissions and the pool of sequestered carbon could be strongly linked to the type and rate of viral infection. Viral replication mechanism choice will consequently influence the microbial efficiency of organic matter assimilation and thus the ultimate fate of carbon as a greenhouse gas or stored in soils.
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Affiliation(s)
- Giuditta Bonetti
- Faculty of Science, Engineering and Built Environment, School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, VIC, Australia
| | - Stacey M Trevathan-Tackett
- Faculty of Science, Engineering and Built Environment, School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, VIC, Australia
| | - Paul E Carnell
- Faculty of Science, Engineering and Built Environment, School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, VIC, Australia
| | - Peter I Macreadie
- Faculty of Science, Engineering and Built Environment, School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, VIC, Australia
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41
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Rates of Molecular Evolution in a Marine Synechococcus Phage Lineage. Viruses 2019; 11:v11080720. [PMID: 31390807 PMCID: PMC6722890 DOI: 10.3390/v11080720] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/27/2019] [Accepted: 07/31/2019] [Indexed: 12/30/2022] Open
Abstract
Cyanophages are characterized by vast genomic diversity and the formation of stable ecotypes over time. The evolution of phage diversity includes vertical processes, such as mutation, and horizontal processes, such as recombination and gene transfer. Here, we study the contribution of vertical and horizontal processes to short-term evolution of marine cyanophages. Analyzing time series data of Synechococcus-infecting Myoviridae ecotypes spanning up to 17 years, we found a high contribution of recombination relative to mutation (r/m) in all ecotypes. Additionally, we found a molecular clock of substitution and recombination in one ecotype, RIM8. The estimated RIM8 evolutionary rates are 2.2 genome-wide substitutions per year (1.275 × 10−5 substitutions/site/year) and 29 genome-wide nucleotide alterations due to recombination per year. We found 26 variable protein families, of which only two families have a predicted functional annotation, suggesting that they are auxiliary metabolic genes with bacterial homologs. A comparison of our rate estimates to other phage evolutionary rate estimates in the literature reveals a negative correlation of phage substitution rates with their genome size. A comparison to evolutionary rates in bacterial organisms further shows that phages have high rates of mutation and recombination compared to their bacterial hosts. We conclude that the increased recombination rate in phages likely contributes to their vast genomic diversity.
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42
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Heaton SM. Harnessing host-virus evolution in antiviral therapy and immunotherapy. Clin Transl Immunology 2019; 8:e1067. [PMID: 31312450 PMCID: PMC6613463 DOI: 10.1002/cti2.1067] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/07/2019] [Accepted: 06/09/2019] [Indexed: 02/06/2023] Open
Abstract
Pathogen resistance and development costs are major challenges in current approaches to antiviral therapy. The high error rate of RNA synthesis and reverse‐transcription confers genome plasticity, enabling the remarkable adaptability of RNA viruses to antiviral intervention. However, this property is coupled to fundamental constraints including limits on the size of information available to manipulate complex hosts into supporting viral replication. Accordingly, RNA viruses employ various means to extract maximum utility from their informationally limited genomes that, correspondingly, may be leveraged for effective host‐oriented therapies. Host‐oriented approaches are becoming increasingly feasible because of increased availability of bioactive compounds and recent advances in immunotherapy and precision medicine, particularly genome editing, targeted delivery methods and RNAi. In turn, one driving force behind these innovations is the increasingly detailed understanding of evolutionarily diverse host–virus interactions, which is the key concern of an emerging field, neo‐virology. This review examines biotechnological solutions to disease and other sustainability issues of our time that leverage the properties of RNA and DNA viruses as developed through co‐evolution with their hosts.
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Affiliation(s)
- Steven M Heaton
- Department of Biochemistry & Molecular Biology Monash University Clayton VIC Australia
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