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Wu R, Davison MR, Nelson WC, Smith ML, Lipton MS, Jansson JK, McClure RS, McDermott JE, Hofmockel KS. Hi-C metagenome sequencing reveals soil phage-host interactions. Nat Commun 2023; 14:7666. [PMID: 37996432 PMCID: PMC10667309 DOI: 10.1038/s41467-023-42967-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 10/27/2023] [Indexed: 11/25/2023] Open
Abstract
Bacteriophages are abundant in soils. However, the majority are uncharacterized, and their hosts are unknown. Here, we apply high-throughput chromosome conformation capture (Hi-C) to directly capture phage-host relationships. Some hosts have high centralities in bacterial community co-occurrence networks, suggesting phage infections have an important impact on the soil bacterial community interactions. We observe increased average viral copies per host (VPH) and decreased viral transcriptional activity following a two-week soil-drying incubation, indicating an increase in lysogenic infections. Soil drying also alters the observed phage host range. A significant negative correlation between VPH and host abundance prior to drying indicates more lytic infections result in more host death and inversely influence host abundance. This study provides empirical evidence of phage-mediated bacterial population dynamics in soil by directly capturing specific phage-host interactions.
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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
| | - William C Nelson
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Montana L Smith
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Mary S Lipton
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Janet K Jansson
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Ryan S McClure
- 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
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR, 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.
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2
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Chen X, Hu C, Wei W, Yang Y, Weinbauer MG, Li H, Ren S, Ma R, Huang Y, Luo T, Jiao N, Zhang R. Virus-Host Interactions Drive Contrasting Bacterial Diel Dynamics in the Ocean. RESEARCH (WASHINGTON, D.C.) 2023; 6:0213. [PMID: 37614364 PMCID: PMC10443526 DOI: 10.34133/research.0213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 08/05/2023] [Indexed: 08/25/2023]
Abstract
Marine organisms perform a sea of diel rhythmicity. Planktonic diel dynamics have been shown to be driven by light, energy resources, circadian rhythms, and the coordinated coupling of photoautotrophs and heterotrophic bacterioplankton. Here, we explore the diel fluctuation of viral production and decay and their impact on the total and active bacterial community in the coastal and open seawaters of the South China Sea. The results showed that the night-production diel pattern of lytic viral production was concurrent with the lower viral decay at night, contributing to the accumulation of the viral population size during the night for surface waters. The diel variations in bacterial activity, community composition, and diversity were found highly affected by viral dynamics. This was revealed by the finding that bacterial community diversity was positively correlated to lytic viral production in the euphotic zone of the open ocean but was negatively related to lysogenic viral production in the coastal ocean. Such distinct but contrasting correlations suggest that viral life strategies can not only contribute to diversifying bacterial community but also potentially piggyback their host to dominate bacterial community, suggesting the tightly synchronized depth-dependent and habitat-specific diel patterns of virus-host interactions. It further implies that viruses serve as an ecologically important driver of bacterial diel dynamics across the ocean, highlighting the viral roles in bacterial ecological and biogeochemical processes in the ocean.
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Affiliation(s)
- Xiaowei Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
| | - Chen Hu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, PR China
| | - Wei Wei
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
- Research Center for Environmental Ecology and Engineering, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430205, PR China
| | - Yunlan Yang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, PR China
| | - Markus G Weinbauer
- Sorbonne Universités, UPMC, Université Paris 06, CNRS, Laboratoire d'Océanographie de Villefranche (LOV), Villefranche-sur-Mer 06230, France
| | - Hongbo Li
- National Marine Environmental Monitoring Center, Ministry of Ecological Environment, Dalian 116023, PR China
| | - Shiying Ren
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
| | - Ruijie Ma
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
| | - Yibin Huang
- Department of Ocean Sciences, University of California, Santa Cruz, CA, USA
- NOAA/OAR Pacific Marine Environmental Laboratory, Seattle, WA, USA
| | - Tingwei Luo
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, PR China
- Institute for Advanced Study, Shenzhen University, Shenzhen 518055, PR China
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3
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Tong D, Wang Y, Yu H, Shen H, Dahlgren RA, Xu J. Viral lysing can alleviate microbial nutrient limitations and accumulate recalcitrant dissolved organic matter components in soil. THE ISME JOURNAL 2023:10.1038/s41396-023-01438-5. [PMID: 37248401 DOI: 10.1038/s41396-023-01438-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 05/13/2023] [Accepted: 05/22/2023] [Indexed: 05/31/2023]
Abstract
Viruses are critical for regulating microbial communities and biogeochemical processes affecting carbon/nutrient cycling. However, the role of soil phages in controlling microbial physiological traits and intrinsic dissolved organic matter (DOM) properties remains largely unknown. Herein, microcosm experiments with different soil phage concentrates (including no-added phages, inactive phages, and three dilutions of active phages) at two temperatures (15 °C and 25 °C) were conducted to disclose the nutrient and DOM dynamics associated with viral lysing. Results demonstrated three different phases of viral impacts on CO2 emission at both temperatures, and phages played a role in maintaining Q10 within bounds. At both temperatures, microbial nutrient limitations (especially P limitation) were alleviated by viral lysing as determined by extracellular enzyme activity (decreased Vangle with active phages). Additionally, the re-utilization of lysate-derived DOM by surviving microbes stimulated an increase of microbial metabolic efficiency and recalcitrant DOM components (e.g., SUV254, SUV260 and HIX). This research provides direct experimental evidence that the "viral shuttle" exists in soils, whereby soil phages increase recalcitrant DOM components. Our findings advance the understanding of viral controls on soil biogeochemical processes, and provide a new perspective for assessing whether soil phages provide a net "carbon sink" vs. "carbon source" in soils.
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Affiliation(s)
- Di Tong
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
| | - Youjing Wang
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
| | - Haodan Yu
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
| | - Haojie Shen
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
| | - Randy A Dahlgren
- Department of Land, Air and Water Resources, University of California, Davis, CA, USA
| | - Jianming Xu
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China.
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4
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Che R, Bai M, Xiao W, Zhang S, Wang Y, Cui X. Nutrient levels and prokaryotes affect viral communities in plateau lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156033. [PMID: 35597355 DOI: 10.1016/j.scitotenv.2022.156033] [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: 01/23/2022] [Revised: 04/30/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Viruses are the most abundant organisms in aquatic environments. Recent advances of viral metagenomic have greatly expanded our understanding of aquatic viral communities. However, little is known about the difference of viral communities and driving factors in freshwater lake. This study seeks to understand the spatio-temporal variation, differences, and driving factors of viral communities in two plateau lakes (Dianchi and Fuxian Lakes) with significant nutritional differences. The viral communities exhibited apparent seasonal variation in Dianchi Lake, while seasonal influences on the viral communities were greater than location-based influences. Two-thirds of all detected viral taxa were shared in two lakes, but there was variation in the composition of viral communities. Correlations between prokaryotic communities, environmental factors and viral communities were analyzed. The nutrients, chlorophyll a were primarily environmental parameters affecting viral communities, and the prokaryotic community was significantly correlated with the viral community. In addition, several viruses infecting humans were identified in two lakes, with the most abundant being Herpesviridae and Poxviridae. Overall, these findings provide information on the dynamics, composition, and differences of viral and prokaryotic communities in plateau lakes with different nutrient levels. These results suggest that nutritional levels and prokaryotic communities could play an important role in shaping viral communities in freshwater lakes.
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Affiliation(s)
- Raoqiong Che
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming 650091, China
| | - Meng Bai
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming 650091, China
| | - Wei Xiao
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming 650091, China.
| | - Shiying Zhang
- Yunnan Engineering Laboratory of Soil Fertility and Pollution Remediation, Yunnan Agricultural University, Kunming 650201, China
| | - Yongxia Wang
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming 650091, China
| | - Xiaolong Cui
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming 650091, China.
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5
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Harilanto AF, Christelle D, Philippe C, Bettarel Y. Viral life strategies in a heavily anthropized tropical lagoon. FEMS Microbiol Lett 2022; 369:6698716. [DOI: 10.1093/femsle/fnac091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/25/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
Ecological traits of aquatic microorganisms have been poorly investigated in tropical latitudes, especially in lagoons, which are often subjected to strong anthropogenic influence, conducive to microbial development. In this study, we examined the abundance of both viral and bacterial communities, as well as their interactions (lytic and lysogenic infections) in the water and sediment of seven main stations of the Ebrié Lagoon (Ivory Coast) with contrasting levels of eutrophication. The highest bacterial and viral concentrations in both planktonic and benthic samples were found in the most eutrophicated stations, where viral lytic infections also exhibited their highest values. Conversely, the highest fractions of inducible lysogens were measured in the most oligotrophic stations, suggesting that these two main viral life strategies are mutually exclusive in this lagoon. Our findings also revealed the importance that nutrients (especially ammonium) play as drivers of the interactions between viruses and their bacterial hosts in tropical lagoons.
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Affiliation(s)
- Andrianjakarivony Felana Harilanto
- Microbes, Evolution, Phylogeny, and Infection (MEФI) , IHU - Méditerranée Infection, 19–21 Boulevard Jean Moulin, 13005, Marseille , France
- Microbiologie Environnementale Biotechnologie (MEB), Mediterranean Institute of Oceanography (MIO) , 163 avenue de Luminy 13009, Marseille , France
| | - Desnues Christelle
- Microbes, Evolution, Phylogeny, and Infection (MEФI) , IHU - Méditerranée Infection, 19–21 Boulevard Jean Moulin, 13005, Marseille , France
- Microbiologie Environnementale Biotechnologie (MEB), Mediterranean Institute of Oceanography (MIO) , 163 avenue de Luminy 13009, Marseille , France
| | - Cecchi Philippe
- MARBEC, Marine Biodiversity, Exploitation & Conservation, Univ. Montpellier , CNRS, Ifremer, IRD, 093 Place Eugène Bataillon 34090, Montpellier , France
| | - Yvan Bettarel
- MARBEC, Marine Biodiversity, Exploitation & Conservation, Univ. Montpellier , CNRS, Ifremer, IRD, 093 Place Eugène Bataillon 34090, Montpellier , France
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6
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The Life Cycle Transitions of Temperate Phages: Regulating Factors and Potential Ecological Implications. Viruses 2022; 14:v14091904. [PMID: 36146712 PMCID: PMC9502458 DOI: 10.3390/v14091904] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/25/2022] [Accepted: 08/25/2022] [Indexed: 11/17/2022] Open
Abstract
Phages are viruses that infect bacteria. They affect various microbe-mediated processes that drive biogeochemical cycling on a global scale. Their influence depends on whether the infection is lysogenic or lytic. Temperate phages have the potential to execute both infection types and thus frequently switch their infection modes in nature, potentially causing substantial impacts on the host-phage community and relevant biogeochemical cycling. Understanding the regulating factors and outcomes of temperate phage life cycle transition is thus fundamental for evaluating their ecological impacts. This review thus systematically summarizes the effects of various factors affecting temperate phage life cycle decisions in both culturable phage-host systems and natural environments. The review further elucidates the ecological implications of the life cycle transition of temperate phages with an emphasis on phage/host fitness, host-phage dynamics, microbe diversity and evolution, and biogeochemical cycles.
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7
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A holistic genome dataset of bacteria, archaea and viruses of the Pearl River estuary. Sci Data 2022; 9:49. [PMID: 35165305 PMCID: PMC8844013 DOI: 10.1038/s41597-022-01153-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/12/2022] [Indexed: 12/21/2022] Open
Abstract
Estuaries are one of the most important coastal ecosystems. While microbiomes and viromes have been separately investigated in some estuaries, few studies holistically deciphered the genomes and connections of viruses and their microbial hosts along an estuarine salinity gradient. Here we applied deep metagenomic sequencing on microbial and viral communities in surface waters of the Pearl River estuary, one of China’s largest estuaries with strong anthropogenic impacts. Overall, 1,205 non-redundant prokaryotic genomes with ≥50% completeness and ≤10% contamination, and 78,502 non-redundant viral-like genomes were generated from samples of three size fractions and five salinity levels. Phylogenomic analysis and taxonomy classification show that majority of these estuarine prokaryotic and viral genomes are novel at species level according to public databases. Potential connections between the microbial and viral populations were further investigated by host-virus matching. These combined microbial and viral genomes provide an important complement of global marine genome datasets and should greatly facilitate our understanding of microbe-virus interactions, evolution and their implications in estuarine ecosystems. Measurement(s) | bacteria • Archaea • viruses | Technology Type(s) | Shotgun Sequencing | Sample Characteristic - Organism | estuary metagenome | Sample Characteristic - Environment | subtropical estuarine | Sample Characteristic - Location | Pearl river estuary |
Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.17139998
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8
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Dynamics of actively dividing prokaryotes in the western Mediterranean Sea. Sci Rep 2022; 12:2064. [PMID: 35136122 PMCID: PMC8825817 DOI: 10.1038/s41598-022-06120-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 01/25/2022] [Indexed: 11/29/2022] Open
Abstract
Microbial community metabolism and functionality play a key role modulating global biogeochemical processes. However, the metabolic activities and contribution of actively growing prokaryotes to ecosystem energy fluxes remain underexplored. Here we describe the temporal and spatial dynamics of active prokaryotes in the different water masses of the Mediterranean Sea using a combination of bromodeoxyuridine labelling and 16S rRNA gene Illumina sequencing. Bulk and actively dividing prokaryotic communities were drastically different and depth stratified. Alteromonadales were rare in bulk communities (contributing 0.1% on average) but dominated the actively dividing community throughout the overall water column (28% on average). Moreover, temporal variability of actively dividing Alteromonadales oligotypes was evinced. SAR86, Actinomarinales and Rhodobacterales contributed on average 3–3.4% each to the bulk and 11, 8.4 and 8.5% to the actively dividing communities in the epipelagic zone, respectively. SAR11 and Nitrosopumilales contributed less to the actively dividing than to the bulk communities during all the study period. Noticeably, the large contribution of these two taxa to the total prokaryotic communities (23% SAR11 and 26% Nitrosopumilales), especially in the meso- and bathypelagic zones, results in important contributions to actively dividing communities (11% SAR11 and 12% Nitrosopumilales). The intense temporal and spatial variability of actively dividing communities revealed in this study strengthen the view of a highly dynamic deep ocean. Our results suggest that some rare or low abundant phylotypes from surface layers down to the deep sea can disproportionally contribute to the activity of the prokaryotic communities, exhibiting a more dynamic response to environmental changes than other abundant phylotypes, emphasizing the role they might have in community metabolism and biogeochemical processes.
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A novel phage indirectly regulates diatom growth by infecting diatom-associated biofilm-forming bacterium. Appl Environ Microbiol 2022; 88:e0213821. [PMID: 35020448 DOI: 10.1128/aem.02138-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Algae and heterotrophic bacteria have close and intricate interactions, which are regulated by multiple factors in the natural environment. Phages are the major factor determining bacterial mortality. However, their impacts on the algae-associated bacteria and thus on the algae-bacteria interactions are poorly understood. Here, we obtained a diatom-associated bacterium Stappia indica SNL01 that could form biofilm and had an inhibitory effect on the growth of diatom Thalassiosira pseudonana. Meanwhile, the phage SI01 with a double-stranded circular DNA genome (44,247 bp) infecting S. indica SNL01 was isolated. Phylogenetic analysis revealed that phage SI01 represents a novel member of the Podoviridae family. The phage contained multiple lysis genes encoding for cell wall lysing muramidase and spore cortex lysing SleB, as well as depolymerase-like tail spike protein. By lysing the host bacterium and inhibiting the formation of biofilm, this phage could indirectly promote the growth of the diatom. Our results shed new insights into how phages indirectly regulate algal growth by infecting bacteria closely associated with algae or in the phycosphere. IMPORTANCE The impact of phage infection on the algae-bacteria relationship in the ocean is poorly understood. Here, a novel phage infecting the diatom-associated bacterium Stappia indica SNL01 was isolated. This bacterium could form biofilm and had a negative effect on diatom growth. We revealed that this phage contained multiple lysis genes and could inhibit the formation of bacterial biofilm, thus indirectly promoting diatom growth. This study implicates that phages are not only important regulators of bacteria but also have substantial indirect effects on algae as well as the algae-bacteria relationship.
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Chen X, Wei W, Xiao X, Wallace D, Hu C, Zhang L, Batt J, Liu J, Gonsior M, Zhang Y, LaRoche J, Hill P, Xu D, Wang J, Jiao N, Zhang R. Heterogeneous viral contribution to dissolved organic matter processing in a long-term macrocosm experiment. ENVIRONMENT INTERNATIONAL 2022; 158:106950. [PMID: 34715430 DOI: 10.1016/j.envint.2021.106950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 09/21/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Viruses saturate environments throughout the world and play key roles in microbial food webs, yet how viral activities affect dissolved organic matter (DOM) processing in natural environments remains elusive. We established a large-scale long-term macrocosm experiment to explore viral dynamics and their potential impacts on microbial mortality and DOM quantity and quality in starved and stratified ecosystems. High viral infection dynamics and the virus-induced cell lysis (6.23-64.68% d-1) was found in the starved seawater macrocosm, which contributed to a significant transformation of microbial biomass into DOM (0.72-5.32 μg L-1 d-1). In the stratified macrocosm, a substantial amount of viral lysate DOM (2.43-17.87 μg L-1 d-1) was released into the upper riverine water, and viral lysis and DOM release (0.35-5.75 μg L-1 d-1) were reduced in the mixed water layer between riverine water and seawater. Viral lysis was stimulated at the bottom of stratified macrocosm, potentially fueled by the sinking of particulate organic carbon. Significant positive and negative associations between lytic viral production and different fluorescent DOM components were found in the starved and stratified macrocosm, indicating the potentially complex viral impacts on the production and utilization of DOM. Results also revealed the significant viral contribution to pools of both relatively higher molecular weight labile DOM and lower molecular weight recalcitrant DOM. Our study suggests that viruses have heterogeneous impact on the cycling and fate of DOM in aquatic environments.
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Affiliation(s)
- Xiaowei Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China
| | - Wei Wei
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China; College of the Environment and Ecology, Xiamen University, Xiamen 361102, PR China
| | - Xilin Xiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China
| | - Douglas Wallace
- Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China; Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Chen Hu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China
| | - Lianbao Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China
| | - John Batt
- Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China; Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jihua Liu
- Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China; Institute of Marine Science and Technology, Shandong University, Qingdao 266237, PR China
| | - Michael Gonsior
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD 20688, United States
| | - Yao Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China
| | - Julie LaRoche
- Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China; Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Paul Hill
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Dapeng Xu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China
| | - Jianning Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China.
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, 361102 Xiamen, PR China; Joint Lab for Ocean Research and Education (LORE) of Dalhousie University, Canada, and Shandong University and Xiamen University, PR China.
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11
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Yang Y, Zhang F, Chen X, Li H, Jiao N, Zhang R. Insignificant Response of Bacterioplankton Community to Elevated pCO 2 During a Short-Term Microcosm Experiment in a Subtropical Eutrophic Coastal Ecosystem. Front Microbiol 2021; 12:730377. [PMID: 34867847 PMCID: PMC8633418 DOI: 10.3389/fmicb.2021.730377] [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] [Received: 06/24/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Ocean acidification, as one of the major consequences of global climate change, markedly affects multiple ecosystem functions in disparate marine environments from coastal habitats to the deep ocean. Evaluation of the responses of marine microbial community to the increasing partial pressure of CO2 (pCO2) is crucial to explore the microbe-driven biogeochemical processes in the future ocean. In this study, a microcosm incubation of eutrophic coastal water from Xiamen Bay under elevated pCO2 (about 1,000 μatm) and control (ambient air, about 380-410 μatm) conditions was conducted to investigate the effect of ocean acidification on the natural bacterioplankton community. During the 5-day incubation period, the chlorophyll a concentration and bacterioplankton abundance were not significantly affected by increased pCO2. Hierarchical clustering and non-metric multidimensional scaling analysis based on Bray-Curtis similarity among the bacterioplankton community derived from the 16S rRNA genes revealed an inconspicuous impact of elevated pCO2 on the bacterial community. During the incubation period, Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, and Epsilonbacteraeota were predominant in all microcosms. Despite the distinct temporal variation in the composition of the bacterioplankton community during the experimental period, statistical analyses showed that no significant difference was found on bacterioplankton taxa between elevated pCO2 and control, indicating that the bacterioplankton at the population-level were also insensitive to elevated pCO2. Our results therefore suggest that the bacterioplankton communities in the fluctuating and eutrophic coastal ecosystems appear to be adaptable to the short-term elevated pCO2.
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Affiliation(s)
- Yunlan Yang
- College of the Environment and Ecology, Xiamen University, Xiamen, China.,State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
| | - Fei Zhang
- College of the Environment and Ecology, Xiamen University, Xiamen, China.,Laboratory of Marine Biology and Ecology, Ministry of Natural Resources, Third Institute of Oceanography, Xiamen, China
| | - Xiaowei Chen
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Huifang Li
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
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12
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Makky S, Dawoud A, Safwat A, Abdelsattar AS, Rezk N, El-Shibiny A. The bacteriophage decides own tracks: When they are with or against the bacteria. CURRENT RESEARCH IN MICROBIAL SCIENCES 2021; 2:100050. [PMID: 34841341 PMCID: PMC8610337 DOI: 10.1016/j.crmicr.2021.100050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/09/2021] [Accepted: 07/20/2021] [Indexed: 11/18/2022] Open
Abstract
Bacteriophages, bacteria-infecting viruses, are considered by many researchers a promising solution for antimicrobial resistance. On the other hand, some phages have shown contribution to bacterial resistance phenomenon by transducing antimicrobial resistance genes to their bacterial hosts. Contradictory consequences of infections are correlated to different phage lifecycles. Out of four known lifecycles, lysogenic and lytic pathways have been riddles since the uncontrolled conversion between them could negatively affect the intended use of phages. However, phages still can be engineered for applications against bacterial and viral infections to ensure high efficiency. This review highlights two main aspects: (1) the different lifecycles as well as the different factors that affect lytic-lysogenic switch are discussed, including the intracellular and molecular factors control this decision. In addition, different models which describe the effect of phages on the ecosystem are compared, besides the approaches to study the switch. (2) An overview on the contribution of the phage in the evolution of the bacteria, instead of eating them, as a consequence of different mode of actions. As well, how phage display has helped in restricting phage cheating and how it could open new gates for immunization and pandemics control will be tacked.
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Affiliation(s)
- Salsabil Makky
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12578, Egypt
| | - Alyaa Dawoud
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12578, Egypt
- Faculty of Pharmacy and Biotechnology, German University in Cairo, New Cairo, 16482, Egypt
| | - Anan Safwat
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12578, Egypt
| | - Abdallah S. Abdelsattar
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12578, Egypt
- Center for X-Ray and Determination of Structure of Matter, Zewail City of Science and Technology, October Gardens, 6th of October, Giza, 12578, Egypt
| | - Nouran Rezk
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12578, Egypt
| | - Ayman El-Shibiny
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12578, Egypt
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13
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Liang X, Wang Y, Zhang Y, Li B, Radosevich M. Bacteriophage-host depth distribution patterns in soil are maintained after nutrient stimulation in vitro. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 787:147589. [PMID: 33991924 DOI: 10.1016/j.scitotenv.2021.147589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/16/2021] [Accepted: 05/01/2021] [Indexed: 06/12/2023]
Abstract
Previous research has revealed the ecological importance of viruses in different ecosystems. However, bacteriophage-host distribution patterns in soil depth profiles have not been investigated. Environmental factors such as nutrient availability and physiological stress can impact the mode (either lytic or lysogenic) of viral reproduction and subsequent influence of virus infection on ecological processes. Soil depth profiles with distinct geochemical properties are ideal models to investigate the virus-host relationships as a function of environmental trophic status and cell abundance. Batch enrichment experiments using soil collected at varying depths (0-140 cm) as inoculum were performed to explore the interactions between viruses and co-occurring microbial hosts under nutrient stimulation. Both viral and bacterial abundance increased in the nutrient media compared with those in the original soils. Bacterial abundance was similar in mixed-cultures of soils regardless of sampling depth, whereas viral abundance was negatively correlated with the depth of soil samples which caused a decreasing virus-to-bacteria ratio. The lysogenetic fraction increased with soil depth in a similar manner as in the original soils assessed directly without nutrient stimulation. The bacterial diversity decreased with soil depth, and was influenced primarily by soil type, viral abundance, and virus-to-bacteria ratio. The bacterial communities were dominated by Bacilli, Beta-, Gamma-Proteobacteria, and Clostridia after nutrient stimulation. Viral and bacterial community structure also varied with soil horizons (i.e., depth). The results showed that the patterns for virus-host interactions shaped by the geochemical properties in the original environment were conserved or similar after in vitro nutrient stimulation. These findings suggest that short-term changes in trophic status alone may not significantly alter the balance of viral reproductive strategies in terrestrial ecosystems as in the antecedent environmental conditions that the host community has long adapted to, and other factors such as stress, host diversity or adaptation may be necessary to trigger community-level shifts in the interactions between viruses and hosts that responded most favorably to nutrient addition.
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Affiliation(s)
- Xiaolong Liang
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA.
| | - Yusong Wang
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA
| | - Ying Zhang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning Province 110016, China
| | - Bingxue Li
- College of Land and Environment, Shenyang Agricultural University, Shenyang, Liaoning 110866, China
| | - Mark Radosevich
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA.
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14
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Silveira CB, Luque A, Rohwer F. The landscape of lysogeny across microbial community density, diversity and energetics. Environ Microbiol 2021; 23:4098-4111. [PMID: 34121301 DOI: 10.1111/1462-2920.15640] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/08/2021] [Accepted: 06/11/2021] [Indexed: 12/11/2022]
Abstract
Lysogens are common at high bacterial densities, an observation that contrasts with the prevailing view of lysogeny as a low-density refugium strategy. Here, we review the mechanisms regulating lysogeny in complex communities and show that the additive effects of coinfections, diversity and host energic status yield a bimodal distribution of lysogeny as a function of microbial densities. At high cell densities (above 106 cells ml-1 or g-1 ) and low diversity, coinfections by two or more phages are frequent and excess energy availability stimulates inefficient metabolism. Both mechanisms favour phage integration and characterize the Piggyback-the-Winner dynamic. At low densities (below 105 cells ml-1 or g-1 ), starvation represses lytic genes and extends the time window for lysogenic commitment, resulting in a higher frequency of coinfections that cause integration. This pattern follows the predictions of the refugium hypothesis. At intermediary densities (between 105 and 106 cells ml-1 or g-1 ), encounter rates and efficient energy metabolism favour lysis. This may involve Kill-the-Winner lytic dynamics and induction. Based on these three regimes, we propose a framework wherein phage integration occurs more frequently at both ends of the host density gradient, with distinct underlying molecular mechanisms (coinfections and host metabolism) dominating at each extreme.
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Affiliation(s)
- Cynthia B Silveira
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL, 33143, USA.,Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, 4600 Rickenbacker Causeway, Miami, FL, 33149, USA
| | - Antoni Luque
- Viral Information Institute, San Diego State University, 5500 Campanile Dr., San Diego, CA, 92182, USA.,Department of Mathematics and Statistics, San Diego State University, 5500 Campanile Dr., San Diego, CA, 92182, USA.,Computational Science Research Center, San Diego State University, 5500 Campanile Dr, San Diego, CA, 92182, USA
| | - Forest Rohwer
- Viral Information Institute, San Diego State University, 5500 Campanile Dr., San Diego, CA, 92182, USA.,Department of Biology, San Diego State University, 5500 Campanile Dr, San Diego, CA, 92182, USA
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15
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Revisiting marine lytic and lysogenic virus-host interactions: Kill-the-Winner and Piggyback-the-Winner. Sci Bull (Beijing) 2021; 66:871-874. [PMID: 36654234 DOI: 10.1016/j.scib.2020.12.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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16
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Malits A, Boras JA, Balagué V, Calvo E, Gasol JM, Marrasé C, Pelejero C, Pinhassi J, Sala MM, Vaqué D. Viral-Mediated Microbe Mortality Modulated by Ocean Acidification and Eutrophication: Consequences for the Carbon Fluxes Through the Microbial Food Web. Front Microbiol 2021; 12:635821. [PMID: 33935996 PMCID: PMC8079731 DOI: 10.3389/fmicb.2021.635821] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Anthropogenic carbon emissions are causing changes in seawater carbonate chemistry including a decline in the pH of the oceans. While its aftermath for calcifying microbes has been widely studied, the effect of ocean acidification (OA) on marine viruses and their microbial hosts is controversial, and even more in combination with another anthropogenic stressor, i.e., human-induced nutrient loads. In this study, two mesocosm acidification experiments with Mediterranean waters from different seasons revealed distinct effects of OA on viruses and viral-mediated prokaryotic mortality depending on the trophic state and the successional stage of the plankton community. In the winter bloom situation, low fluorescence viruses, the most abundant virus-like particle (VLP) subpopulation comprising mostly bacteriophages, were negatively affected by lowered pH with nutrient addition, while the bacterial host abundance was stimulated. High fluorescence viruses, containing cyanophages, were stimulated by OA regardless of the nutrient conditions, while cyanobacteria of the genus Synechococcus were negatively affected by OA. Moreover, the abundance of very high fluorescence viruses infecting small haptophytes tended to be lower under acidification while their putative hosts' abundance was enhanced, suggesting a direct and negative effect of OA on viral-host interactions. In the oligotrophic summer situation, we found a stimulating effect of OA on total viral abundance and the viral populations, suggesting a cascading effect of the elevated pCO2 stimulating autotrophic and heterotrophic production. In winter, viral lysis accounted for 30 ± 16% of the loss of bacterial standing stock per day (VMMBSS) under increased pCO2 compared to 53 ± 35% in the control treatments, without effects of nutrient additions while in summer, OA had no significant effects on VMMBSS (35 ± 20% and 38 ± 5% per day in the OA and control treatments, respectively). We found that phage production and resulting organic carbon release rates significantly reduced under OA in the nutrient replete winter situation, but it was also observed that high nutrient loads lowered the negative effect of OA on viral lysis, suggesting an antagonistic interplay between these two major global ocean stressors in the Anthropocene. In summer, however, viral-mediated carbon release rates were lower and not affected by lowered pH. Eutrophication consistently stimulated viral production regardless of the season or initial conditions. Given the relevant role of viruses for marine carbon cycling and the biological carbon pump, these two anthropogenic stressors may modulate carbon fluxes through their effect on viruses at the base of the pelagic food web in a future global change scenario.
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Affiliation(s)
- Andrea Malits
- Biological Oceanography Laboratory, Austral Center for Scientific Research (CONICET), Ushuaia, Argentina
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
| | - Julia A. Boras
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
| | - Vanessa Balagué
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
| | - Eva Calvo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
| | - Josep M. Gasol
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
- Center for Marine Ecosystems Research, School of Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Cèlia Marrasé
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
| | - Carles Pelejero
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Jarone Pinhassi
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Maria Montserrat Sala
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
| | - Dolors Vaqué
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
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17
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Hu C, Chen X, Yu L, Xu D, Jiao N. Elevated Contribution of Low Nucleic Acid Prokaryotes and Viral Lysis to the Prokaryotic Community Along the Nutrient Gradient From an Estuary to Open Ocean Transect. Front Microbiol 2020; 11:612053. [PMID: 33424815 PMCID: PMC7793805 DOI: 10.3389/fmicb.2020.612053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/20/2020] [Indexed: 11/30/2022] Open
Abstract
Prokaryotes represent the largest living biomass reservoir in aquatic environments and play a crucial role in the global ocean. However, the factors that shape the abundance and potential growth rate of the ecologically distinct prokaryotic subgroups [i.e., high nucleic acid (HNA) and low nucleic acid (LNA) cells] along varying trophic conditions in the ocean remain poorly understood. This study conducted a series of modified dilution experiments to investigate how the abundance and potential growth rate of HNA and LNA prokaryotes and their regulating factors (i.e., protozoan grazing and viral lysis) change along a cross-shore nutrient gradient in the northern South China Sea. The results showed that the abundance of both HNA and LNA cells was significantly positively correlated with the abundance of heterotrophic nanoflagellates and viruses, whereas only HNA abundance exhibited a significant positive correlation with nutrient level. With a decreasing nutrient concentration, the potential growth rate of the HNA subgroup declined significantly, while that of the LNA subgroup was significantly enhanced, leading to an elevated relative potential growth rate of the LNA to HNA subgroup under decreasing nutrient levels. Furthermore, our data revealed different regulatory roles of protozoan grazing and viral lysis on the HNA and LNA subgroups, with HNA suffering higher mortality pressure from grazing than from lysis in contrast to LNA, which experienced equivalent pressures. As the nutrient levels declined, the relative contribution of lysis to the mortality of the HNA subgroup increased significantly, in contrast to the insignificant change in that of the LNA subgroup. Our results indicated the elevated role of LNA cells in the prokaryotic community and the enhanced viral lysis pressure on the total prokaryotes under oligotrophic conditions. This implies a weakened efficiency of carbon cycling within the microbial loop and enhanced viral lysis to shunt more carbon and energy flow in the future ocean, in which oligotrophication will be strengthened due to global warming.
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Affiliation(s)
- Chen Hu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, China.,Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
| | - Xiaowei Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, China.,Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
| | - Liuqian Yu
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Dapeng Xu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, China.,Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, China.,Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
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18
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Pradeep Ram AS, Keshri J, Sime-Ngando T. Differential impact of top-down and bottom-up forces in structuring freshwater bacterial communities. FEMS Microbiol Ecol 2020; 96:5700279. [PMID: 31922543 DOI: 10.1093/femsec/fiaa005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/09/2020] [Indexed: 01/21/2023] Open
Abstract
Limited data exist on the simultaneous impact of bottom-up (nutrients) and top-down (viruses and heterotrophic nanoflagellates) forces in shaping freshwater bacterial communities. In our laboratory microcosms, nutrient additions (organic and inorganic) and viral reduction approach led to the proliferation of high nucleic acid (HNA) bacterial subpopulation without an increase in phage abundance. High viral-mediated bacterial lysis in the presence of nanoflagellates yielded high proportion of low nucleic acid bacterial subpopulation. 16S rRNA gene sequence analysis indicated that members of classes Proteobacteria and Bacteroidetes evoked differential responses to nutrients and mortality forces, thereby resulting in differences (P < 0.001) in bacterial community composition and diversity, as observed from analysis of similarities and UniFrac analysis. Bacterial species richness (Chao) and diversity (Shannon) index was significantly higher (P < 0.001) in the presence of both the top-down factors and viruses alone, whereas lower host diversity was observed under nutrient relaxation of growth-limiting substrates due to the explosive growth of opportunistic HNA bacterial subpopulation. Our results are in agreement with the theoretical model of 'killing the winner', where the availability of growth-limiting substrates can act as a stimulating factor for host community composition while top-down forces can operate in the control of host diversity.
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Affiliation(s)
- A S Pradeep Ram
- Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023, Université Clermont-Auvergne, 63178 Aubière Cedex, France
| | - J Keshri
- Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023, Université Clermont-Auvergne, 63178 Aubière Cedex, France
| | - T Sime-Ngando
- Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023, Université Clermont-Auvergne, 63178 Aubière Cedex, France
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19
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Mena C, Reglero P, Balbín R, Martín M, Santiago R, Sintes E. Seasonal Niche Partitioning of Surface Temperate Open Ocean Prokaryotic Communities. Front Microbiol 2020; 11:1749. [PMID: 32849378 PMCID: PMC7399227 DOI: 10.3389/fmicb.2020.01749] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 07/03/2020] [Indexed: 12/20/2022] Open
Abstract
Surface microbial communities are exposed to seasonally changing environmental conditions, resulting in recurring patterns of community composition. However, knowledge on temporal dynamics of open ocean microbial communities remains scarce. Seasonal patterns and associations of taxa and oligotypes from surface and chlorophyll maximum layers in the western Mediterranean Sea were studied over a 2-year period. Summer stratification versus winter mixing governed not only the prokaryotic community composition and diversity but also the temporal dynamics and co-occurrence association networks of oligotypes. Flavobacteriales, Rhodobacterales, SAR11, SAR86, and Synechococcales oligotypes exhibited contrasting seasonal dynamics, and consequently, specific microbial assemblages and potential inter-oligotype connections characterized the different seasons. In addition, oligotypes composition and dynamics differed between surface and deep chlorophyll maximum (DCM) prokaryotic communities, indicating depth-related environmental gradients as a major factor affecting association networks between closely related taxa. Taken together, the seasonal and depth specialization of oligotypes suggest temporal dynamics of community composition and metabolism, influencing ecosystem function and global biogeochemical cycles. Moreover, our results indicate highly specific associations between microbes, pointing to keystone ecotypes and fine-tuning of the microbes realized niche.
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Affiliation(s)
- Catalina Mena
- Instituto Español de Oceanografía (IEO), Centre Oceanogràfic de les Balears, Ecosystem Oceanography Group (GRECO), Palma, Spain
| | - Patricia Reglero
- Instituto Español de Oceanografía (IEO), Centre Oceanogràfic de les Balears, Ecosystem Oceanography Group (GRECO), Palma, Spain
| | - Rosa Balbín
- Instituto Español de Oceanografía (IEO), Centre Oceanogràfic de les Balears, Ecosystem Oceanography Group (GRECO), Palma, Spain
| | - Melissa Martín
- Instituto Español de Oceanografía (IEO), Centre Oceanogràfic de les Balears, Ecosystem Oceanography Group (GRECO), Palma, Spain
| | - Rocío Santiago
- Instituto Español de Oceanografía (IEO), Centre Oceanogràfic de les Balears, Ecosystem Oceanography Group (GRECO), Palma, Spain
| | - Eva Sintes
- Instituto Español de Oceanografía (IEO), Centre Oceanogràfic de les Balears, Ecosystem Oceanography Group (GRECO), Palma, Spain
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20
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White RA, Visscher PT, Burns BP. Between a Rock and a Soft Place: The Role of Viruses in Lithification of Modern Microbial Mats. Trends Microbiol 2020; 29:204-213. [PMID: 32654857 DOI: 10.1016/j.tim.2020.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/07/2020] [Accepted: 06/16/2020] [Indexed: 12/22/2022]
Abstract
Stromatolites are geobiological systems formed by complex microbial communities, and fossilized stromatolites provide a record of some of the oldest life on Earth. Microbial mats are precursors of extant stromatolites; however, the mechanisms of transition from mat to stromatolite are controversial and are still not well understood. To fully recognize the profound impact that these ecosystems have had on the evolution of the biosphere requires an understanding of modern lithification mechanisms and how they relate to the geological record. We propose here viral mechanisms in carbonate precipitation, leading to stromatolite formation, whereby viruses directly or indirectly impact microbial metabolisms that govern the transition from microbial mat to stromatolite. Finding a tangible link between host-virus interactions and changes in biogeochemical processes will provide tools to interpret mineral biosignatures through geologic time, including those on Earth and beyond.
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Affiliation(s)
- Richard Allen White
- Plant Pathology, Washington State University, Pullman, WA, USA; Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia; RAW Molecular Systems (RMS) LLC, Spokane, WA, USA
| | - Pieter T Visscher
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia; Departments of Marine Sciences and Geosciences, University of Connecticut, CT, USA; Biogeosciences, the Université de Bourgogne Franche-Comté, Dijon, France
| | - Brendan P Burns
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia; School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia.
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