1
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Queirós AM, Tait K, Clark JR, Bedington M, Pascoe C, Torres R, Somerfield PJ, Smale DA. Identifying and protecting macroalgae detritus sinks toward climate change mitigation. Ecol Appl 2023; 33:e2798. [PMID: 36504412 DOI: 10.1002/eap.2798] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 08/11/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023]
Abstract
Harnessing natural solutions to mitigate climate change requires an understanding of carbon fixation, flux, and sequestration across ocean habitats. Recent studies have suggested that exported seaweed particulate organic carbon is stored within soft-sediment systems. However, very little is known about how seaweed detritus disperses from coastlines, or where it may enter seabed carbon stores, where it could become the target of conservation efforts. Here, focusing on regionally dominant seaweed species, we surveyed environmental DNA (eDNA) from natural coastal sediments, and studied their connectivity to seaweed habitats using a particle tracking model parameterized to reproduce seaweed detritus dispersal behavior based on laboratory observations of seaweed fragment degradation and sinking. Experiments showed that seaweed detritus density changed over time, differently across species. This, in turn, modified distances traveled by released fragments until they reached the seabed for the first time, during model simulations. Dispersal pathways connected detritus from the shore to the open ocean but, importantly, also to coastal sediments, and this was reflected by field eDNA evidence. Dispersion pathways were also affected by hydrodynamic conditions, varying in space and time. Both the properties and timing of released detritus, individual to each macroalgal population, and short-term near-seabed and medium-term water-column transport pathways, are thus seemingly important in determining the connectivity between seaweed habitats and potential sedimentary sinks. Studies such as this one, supported by further field verification of sedimentary carbon sequestration rates and source partitioning, are still needed to help quantify the role of seaweed in the ocean carbon cycle. Such studies will provide vital evidence to inform on the potential need to develop blue carbon conservation mechanisms, beyond wetlands.
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Affiliation(s)
| | - Karen Tait
- Plymouth Marine Laboratory, Plymouth, UK
| | | | | | | | | | | | - Dan A Smale
- Marine Biological Association of the United Kingdom, Plymouth, UK
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2
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Bolaños LM, Tait K, Somerfield PJ, Parsons RJ, Giovannoni SJ, Smyth T, Temperton B. Influence of short and long term processes on SAR11 communities in open ocean and coastal systems. ISME Commun 2022; 2:116. [PMID: 37938786 PMCID: PMC9723719 DOI: 10.1038/s43705-022-00198-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/21/2022] [Accepted: 11/01/2022] [Indexed: 07/18/2023]
Abstract
SAR11 bacteria dominate the surface ocean and are major players in converting fixed carbon back to atmospheric carbon dioxide. The SAR11 clade is comprised of niche-specialized ecotypes that display distinctive spatiotemporal transitions. We analyzed SAR11 ecotype seasonality in two long-term 16S rRNA amplicon time series representing different North Atlantic regimes: the Sargasso Sea (subtropical ocean-gyre; BATS) and the temperate coastal Western English Channel (WEC). Using phylogenetically resolved amplicon sequence variants (ASVs), we evaluated seasonal environmental constraints on SAR11 ecotype periodicity. Despite large differences in temperature and nutrient availability between the two sites, at both SAR11 succession was defined by summer and winter clusters of ASVs. The summer cluster was dominated by ecotype Ia.3 in both sites. Winter clusters were dominated by ecotypes Ib and IIa.A at BATS and Ia.1 and IIa.B at WEC. A 2-year weekly analysis within the WEC time series showed that the response of SAR11 communities to short-term environmental fluctuations was variable. In 2016, community shifts were abrupt and synchronized to environmental shifts. However, in 2015, changes were gradual and decoupled from environmental fluctuations, likely due to increased mixing from strong winds. We demonstrate that interannual weather variability disturb the pace of SAR11 seasonal progression.
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Affiliation(s)
- Luis M Bolaños
- School of Biosciences, University of Exeter, Exeter, UK.
| | - Karen Tait
- Plymouth Marine Laboratory, Plymouth, UK
| | | | | | | | | | - Ben Temperton
- School of Biosciences, University of Exeter, Exeter, UK.
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3
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März C, Freitas FS, Faust JC, Godbold JA, Henley SF, Tessin AC, Abbott GD, Airs R, Arndt S, Barnes DKA, Grange LJ, Gray ND, Head IM, Hendry KR, Hilton RG, Reed AJ, Rühl S, Solan M, Souster TA, Stevenson MA, Tait K, Ward J, Widdicombe S. Biogeochemical consequences of a changing Arctic shelf seafloor ecosystem. Ambio 2022; 51:370-382. [PMID: 34628602 PMCID: PMC8692578 DOI: 10.1007/s13280-021-01638-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 09/02/2021] [Accepted: 09/22/2021] [Indexed: 05/05/2023]
Abstract
Unprecedented and dramatic transformations are occurring in the Arctic in response to climate change, but academic, public, and political discourse has disproportionately focussed on the most visible and direct aspects of change, including sea ice melt, permafrost thaw, the fate of charismatic megafauna, and the expansion of fisheries. Such narratives disregard the importance of less visible and indirect processes and, in particular, miss the substantive contribution of the shelf seafloor in regulating nutrients and sequestering carbon. Here, we summarise the biogeochemical functioning of the Arctic shelf seafloor before considering how climate change and regional adjustments to human activities may alter its biogeochemical and ecological dynamics, including ecosystem function, carbon burial, or nutrient recycling. We highlight the importance of the Arctic benthic system in mitigating climatic and anthropogenic change and, with a focus on the Barents Sea, offer some observations and our perspectives on future management and policy.
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Affiliation(s)
- Christian März
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT UK
| | - Felipe S. Freitas
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1QE UK
| | - Johan C. Faust
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT UK
- MARUM—Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse 8, 28359 Bremen, Germany
| | - Jasmin A. Godbold
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - Sian F. Henley
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh, EH9 3FE UK
| | - Allyson C. Tessin
- Department of Geology, Kent State University, 221 McGilvrey Hall, 325 S. Lincoln St., Kent, OH 44242 USA
| | - Geoffrey D. Abbott
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
| | - Ruth Airs
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH UK
| | - Sandra Arndt
- Department of Geosciences, Environment and Society, Université libre de Bruxelles, Brussels, Av. F.
Roosevelt 50, CP160/02, 1050 Brussels, Belgium
| | - David K. A. Barnes
- British Antarctic Survey, UKRI, High Cross, Maddingley Rd, Cambridge, CB3 0ET UK
| | - Laura J. Grange
- School of Ocean Sciences, Bangor University, Bangor, Gwynedd, LL57 2DG North Wales UK
| | - Neil D. Gray
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
| | - Ian M. Head
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
| | - Katharine R. Hendry
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1QE UK
| | - Robert G. Hilton
- Department of Geography, Durham University, Lower Mountjoy, South Rd, Durham, DH1 3LE USA
| | - Adam J. Reed
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - Saskia Rühl
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH UK
- Helmholtz Zentrum Hereon, Max-Planck-Straße 1, 21502 Geesthacht, Germany
| | - Martin Solan
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - Terri A. Souster
- British Antarctic Survey, UKRI, High Cross, Maddingley Rd, Cambridge, CB3 0ET UK
- Department of Biosciences, Fisheries and Economics, UIT, Tromsø, Norway
| | - Mark A. Stevenson
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
- Department of Geography, Durham University, Lower Mountjoy, South Rd, Durham, DH1 3LE USA
| | - Karen Tait
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH UK
| | - James Ward
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1QE UK
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4
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Stevenson MA, Faust JC, Andrade LL, Freitas FS, Gray ND, Tait K, Hendry KR, Hilton RG, Henley SF, Tessin A, Leary P, Papadaki S, Ford A, März C, Abbott GD. Transformation of organic matter in a Barents Sea sediment profile: coupled geochemical and microbiological processes. Philos Trans A Math Phys Eng Sci 2020; 378:20200223. [PMID: 32862813 PMCID: PMC7481670 DOI: 10.1098/rsta.2020.0223] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Process-based, mechanistic investigations of organic matter transformation and diagenesis directly beneath the sediment-water interface (SWI) in Arctic continental shelves are vital as these regions are at greatest risk of future change. This is in part due to disruptions in benthic-pelagic coupling associated with ocean current change and sea ice retreat. Here, we focus on a high-resolution, multi-disciplinary set of measurements that illustrate how microbial processes involved in the degradation of organic matter are directly coupled with inorganic and organic geochemical sediment properties (measured and modelled) as well as the extent/depth of bioturbation. We find direct links between aerobic processes, reactive organic carbon and highest abundances of bacteria and archaea in the uppermost layer (0-4.5 cm depth) followed by dominance of microbes involved in nitrate/nitrite and iron/manganese reduction across the oxic-anoxic redox boundary (approx. 4.5-10.5 cm depth). Sulfate reducers dominate in the deeper (approx. 10.5-33 cm) anoxic sediments which is consistent with the modelled reactive transport framework. Importantly, organic matter reactivity as tracked by organic geochemical parameters (n-alkanes, n-alkanoic acids, n-alkanols and sterols) changes most dramatically at and directly below the SWI together with sedimentology and biological activity but remained relatively unchanged across deeper changes in sedimentology. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.
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Affiliation(s)
- Mark A. Stevenson
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
- e-mail:
| | - Johan C. Faust
- School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK
| | - Luiza L. Andrade
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Felipe S. Freitas
- School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK
| | - Neil D. Gray
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Karen Tait
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | | | - Robert G. Hilton
- Department of Geography, Science Laboratories, Durham University, South Road, Durham DH1 3LE, UK
| | - Sian F. Henley
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - Allyson Tessin
- Department of Geology, Kent State University, Kent, OH 44240, USA
| | - Peter Leary
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Sonia Papadaki
- School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK
| | - Ailbe Ford
- School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK
| | - Christian März
- School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK
| | - Geoffrey D. Abbott
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
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5
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Queirós AM, Stephens N, Widdicombe S, Tait K, McCoy SJ, Ingels J, Rühl S, Airs R, Beesley A, Carnovale G, Cazenave P, Dashfield S, Hua E, Jones M, Lindeque P, McNeill CL, Nunes J, Parry H, Pascoe C, Widdicombe C, Smyth T, Atkinson A, Krause‐Jensen D, Somerfield PJ. Connected macroalgal‐sediment systems: blue carbon and food webs in the deep coastal ocean. ECOL MONOGR 2019. [DOI: 10.1002/ecm.1366] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Nicholas Stephens
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
- Nereis Bioengineering Llansadwrn SA19 8NA United Kingdom
| | | | - Karen Tait
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | - Sophie J. McCoy
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
- Department of Biological Science Florida State University Tallahassee Florida 32306 USA
| | - Jeroen Ingels
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
- Coastal and Marine Laboratory Florida State University St Teresa Florida 32358 USA
| | - Saskia Rühl
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | - Ruth Airs
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | - Amanda Beesley
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | | | | | | | - Er Hua
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
- Ocean University of China Qingdao 266003 China
| | - Mark Jones
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | | | | | - Joana Nunes
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | - Helen Parry
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | | | | | - Tim Smyth
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
| | - Angus Atkinson
- Plymouth Marine Laboratory Plymouth PL1 3DH United Kingdom
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6
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White DA, Rooks PA, Kimmance S, Tait K, Jones M, Tarran GA, Cook C, Llewellyn CA. Modulation of Polar Lipid Profiles in Chlorella sp. in Response to Nutrient Limitation. Metabolites 2019; 9:metabo9030039. [PMID: 30823401 PMCID: PMC6468466 DOI: 10.3390/metabo9030039] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 11/16/2022] Open
Abstract
We evaluate the effects of nutrient limitation on cellular composition of polar lipid classes/species in Chlorella sp. using modern polar lipidomic profiling methods (liquid chromatography⁻tandem mass spectrometry; LC-MS/MS). Total polar lipid concentration was highest in nutrient-replete (HN) cultures with a significant reduction in monogalactosyldiacylglycerol (MGDG), phosphatidylglycerol (PG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE) class concentrations for nutrient-deplete (LN) cultures. Moreover, reductions in the abundance of MGDG relative to total polar lipids versus an increase in the relative abundance of digalactosyldiacylglycerol (DGDG) were recorded in LN cultures. In HN cultures, polar lipid species composition remained relatively constant throughout culture with high degrees of unsaturation associated with acyl moieties. Conversely, in LN cultures lipid species composition shifted towards greater saturation of acyl moieties. Multivariate analyses revealed that changes in the abundance of a number of species contributed to the dissimilarity between LN and HN cultures but with dominant effects from certain species, e.g., reduction in MGDG 34:7 (18:3/16:4). Results demonstrate that Chlorella sp. significantly alters its polar lipidome in response to nutrient limitation, and this is discussed in terms of physiological significance and polar lipids production for applied microalgal production systems.
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Affiliation(s)
- Daniel A White
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, Devon PL1 3DH, UK.
| | - Paul A Rooks
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, Devon PL1 3DH, UK.
| | - Susan Kimmance
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, Devon PL1 3DH, UK.
| | - Karen Tait
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, Devon PL1 3DH, UK.
| | - Mark Jones
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, Devon PL1 3DH, UK.
| | - Glen A Tarran
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, Devon PL1 3DH, UK.
| | - Charlotte Cook
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, Devon PL1 3DH, UK.
| | - Carole A Llewellyn
- Department of Biosciences, Singleton Park, Swansea University, Swansea, Wales SA2 8PP, UK.
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7
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Tschauner O, Huang S, Greenberg E, Prakapenka VB, Ma C, Rossman GR, Shen AH, Zhang D, Newville M, Lanzirotti A, Tait K. Ice-VII inclusions in diamonds: Evidence for aqueous fluid in Earth’s deep mantle. Science 2018; 359:1136-1139. [DOI: 10.1126/science.aao3030] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 01/19/2018] [Indexed: 11/02/2022]
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8
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Sciberras M, Tait K, Brochain G, Hiddink JG, Hale R, Godbold JA, Solan M. Mediation of nitrogen by post-disturbance shelf communities experiencing organic matter enrichment. Biogeochemistry 2017; 135:135-153. [PMID: 32009695 PMCID: PMC6961516 DOI: 10.1007/s10533-017-0370-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 08/15/2017] [Indexed: 05/26/2023]
Abstract
Microbes and benthic macro-invertebrates interact in sediments to play a major role in the biogeochemical cycling of organic matter, but the extent to which their contributions are modified following natural and anthropogenic changes has received little attention. Here, we investigate how nitrogen transformations, ascertained from changes in archaeal and bacterial N-cycling microbes and water macronutrient concentrations ([NH4-N], [NO2-N], [NO3-N]), in sand and sandy mud sediments differ when macrofaunal communities that have previously experienced contrasting levels of chronic fishing disturbance are exposed to organic matter enrichment. We find that differences in macrofaunal community structure related to differences in fishing activity affect the capacity of the macrofauna to mediate microbial nitrogen cycling in sand, but not in sandy mud environments. Whilst we found no evidence for a change in ammonia oxidiser community structure, we did find an increase in archaeal and bacterial denitrifier (AnirKa, nirS) and anammox (hzo) transcripts in macrofaunal communities characterized by higher ratios of suspension to deposit feeders, and a lower density but higher biomass of sediment-reworking fauna. Our findings suggest that nitrogen transformation in shelf sandy sediments is dependent on the stimulation of specific nitrogen cycling pathways that are associated with differences in the composition and context-dependent expression of the functional traits that belong to the resident bioturbating macrofauna community.
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Affiliation(s)
- Marija Sciberras
- School of Ocean Sciences, Bangor University, Askew St, Menai Bridge, Anglesey LL59 5AB UK
| | - Karen Tait
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - Guillaume Brochain
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - Jan G. Hiddink
- School of Ocean Sciences, Bangor University, Askew St, Menai Bridge, Anglesey LL59 5AB UK
| | - Rachel Hale
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - Jasmin A. Godbold
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - Martin Solan
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
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9
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Currie AR, Tait K, Parry H, de Francisco-Mora B, Hicks N, Osborn AM, Widdicombe S, Stahl H. Marine Microbial Gene Abundance and Community Composition in Response to Ocean Acidification and Elevated Temperature in Two Contrasting Coastal Marine Sediments. Front Microbiol 2017; 8:1599. [PMID: 28878754 PMCID: PMC5572232 DOI: 10.3389/fmicb.2017.01599] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 08/07/2017] [Indexed: 02/01/2023] Open
Abstract
Marine ecosystems are exposed to a range of human-induced climate stressors, in particular changing carbonate chemistry and elevated sea surface temperatures as a consequence of climate change. More research effort is needed to reduce uncertainties about the effects of global-scale warming and acidification for benthic microbial communities, which drive sedimentary biogeochemical cycles. In this research, mesocosm experiments were set up using muddy and sandy coastal sediments to investigate the independent and interactive effects of elevated carbon dioxide concentrations (750 ppm CO2) and elevated temperature (ambient +4°C) on the abundance of taxonomic and functional microbial genes. Specific quantitative PCR primers were used to target archaeal, bacterial, and cyanobacterial/chloroplast 16S rRNA in both sediment types. Nitrogen cycling genes archaeal and bacterial ammonia monooxygenase (amoA) and bacterial nitrite reductase (nirS) were specifically targeted to identify changes in microbial gene abundance and potential impacts on nitrogen cycling. In muddy sediment, microbial gene abundance, including amoA and nirS genes, increased under elevated temperature and reduced under elevated CO2 after 28 days, accompanied by shifts in community composition. In contrast, the combined stressor treatment showed a non-additive effect with lower microbial gene abundance throughout the experiment. The response of microbial communities in the sandy sediment was less pronounced, with the most noticeable response seen in the archaeal gene abundances in response to environmental stressors over time. 16S rRNA genes (amoA and nirS) were lower in abundance in the combined stressor treatments in sandy sediments. Our results indicated that marine benthic microorganisms, especially in muddy sediments, are susceptible to changes in ocean carbonate chemistry and seawater temperature, which ultimately may have an impact upon key benthic biogeochemical cycles.
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Affiliation(s)
- Ashleigh R. Currie
- Biogeochemistry and Earth Science, Scottish Association for Marine Science, Scottish Marine InstituteOban, United Kingdom
| | - Karen Tait
- Plymouth Marine LaboratoryPlymouth, United Kingdom
| | - Helen Parry
- Plymouth Marine LaboratoryPlymouth, United Kingdom
| | - Beatriz de Francisco-Mora
- Biogeochemistry and Earth Science, Scottish Association for Marine Science, Scottish Marine InstituteOban, United Kingdom
| | - Natalie Hicks
- Biogeochemistry and Earth Science, Scottish Association for Marine Science, Scottish Marine InstituteOban, United Kingdom
| | - A. Mark Osborn
- School of Biological Sciences, University of HullHull, United Kingdom
- School of Science, Royal Melbourne Institute of Technology University, BundooraVIC, Australia
| | | | - Henrik Stahl
- Biogeochemistry and Earth Science, Scottish Association for Marine Science, Scottish Marine InstituteOban, United Kingdom
- Natural Science and Public Health, Zayed UniversityDubai, United Arab Emirates
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10
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Thompson CEL, Silburn B, Williams ME, Hull T, Sivyer D, Amoudry LO, Widdicombe S, Ingels J, Carnovale G, McNeill CL, Hale R, Marchais CL, Hicks N, Smith HEK, Klar JK, Hiddink JG, Kowalik J, Kitidis V, Reynolds S, Woodward EMS, Tait K, Homoky WB, Kröger S, Bolam S, Godbold JA, Aldridge J, Mayor DJ, Benoist NMA, Bett BJ, Morris KJ, Parker ER, Ruhl HA, Statham PJ, Solan M. An approach for the identification of exemplar sites for scaling up targeted field observations of benthic biogeochemistry in heterogeneous environments. Biogeochemistry 2017; 135:1-34. [PMID: 32009689 PMCID: PMC6961521 DOI: 10.1007/s10533-017-0366-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 06/08/2017] [Indexed: 05/16/2023]
Abstract
Continental shelf sediments are globally important for biogeochemical activity. Quantification of shelf-scale stocks and fluxes of carbon and nutrients requires the extrapolation of observations made at limited points in space and time. The procedure for selecting exemplar sites to form the basis of this up-scaling is discussed in relation to a UK-funded research programme investigating biogeochemistry in shelf seas. A three-step selection process is proposed in which (1) a target area representative of UK shelf sediment heterogeneity is selected, (2) the target area is assessed for spatial heterogeneity in sediment and habitat type, bed and water column structure and hydrodynamic forcing, and (3) study sites are selected within this target area encompassing the range of spatial heterogeneity required to address key scientific questions regarding shelf scale biogeochemistry, and minimise confounding variables. This led to the selection of four sites within the Celtic Sea that are significantly different in terms of their sediment, bed structure, and macrofaunal, meiofaunal and microbial community structures and diversity, but have minimal variations in water depth, tidal and wave magnitudes and directions, temperature and salinity. They form the basis of a research cruise programme of observation, sampling and experimentation encompassing the spring bloom cycle. Typical variation in key biogeochemical, sediment, biological and hydrodynamic parameters over a pre to post bloom period are presented, with a discussion of anthropogenic influences in the region. This methodology ensures the best likelihood of site-specific work being useful for up-scaling activities, increasing our understanding of benthic biogeochemistry at the UK-shelf scale.
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Affiliation(s)
- C. E. L. Thompson
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH UK
| | - B. Silburn
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - M. E. Williams
- National Oceanography Centre, 6 Brownlow St, Liverpool, L3 5DA UK
| | - T. Hull
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - D. Sivyer
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - L. O. Amoudry
- National Oceanography Centre, 6 Brownlow St, Liverpool, L3 5DA UK
| | - S. Widdicombe
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - J. Ingels
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - G. Carnovale
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - C. L. McNeill
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - R. Hale
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH UK
| | - C. Laguionie Marchais
- National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - N. Hicks
- Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, PA37 1QA UK
| | - H. E. K. Smith
- National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - J. K. Klar
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH UK
- LEGOS, University of Toulouse, IRDm CNES, CNRS, UPS, 14 av. Edouard Belin, 31400 Toulouse, France
| | - J. G. Hiddink
- School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB UK
| | - J. Kowalik
- Navama – Technology for Nature, Landshuter Allee 8, 80637 Munich, Germany
| | - V. Kitidis
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - S. Reynolds
- School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3QL UK
| | - E. M. S. Woodward
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - K. Tait
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - W. B. Homoky
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN UK
| | - S. Kröger
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - S. Bolam
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - J. A. Godbold
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH UK
- Biological Sciences, University of Southampton, Life Sciences Building, Highfield, Southampton SO17 1BJ UK
| | - J. Aldridge
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - D. J. Mayor
- National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - N. M. A. Benoist
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH UK
| | - B. J. Bett
- National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - K. J. Morris
- National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - E. R. Parker
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - H. A. Ruhl
- National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK
| | - P. J. Statham
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH UK
| | - M. Solan
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH UK
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11
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Rees AP, Tait K, Widdicombe CE, Quartly GD, McEvoy AJ, Al-Moosawi L. Metabolically active, non-nitrogen fixing, Trichodesmium in UK coastal waters during winter. J Plankton Res 2016; 38:673-678. [PMID: 27274100 PMCID: PMC4892227 DOI: 10.1093/plankt/fbv123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 12/13/2015] [Indexed: 06/06/2023]
Abstract
Trichodesmium, a colonial cyanobacterium typically associated with tropical waters, was observed between January and April 2014 in the western English Channel. Sequencing of the heterocyst differentiation (hetR) and 16S rRNA genes placed this community within the Clade IV Trichodesmium, an understudied clade previously found only in low numbers in warmer waters. Nitrogen fixation was not detected although measurable rates of nitrate uptake and carbon fixation were observed. Trichodesmium RuBisCO transcript abundance relative to gene abundance suggests the potential for viable and potentially active Trichodesmium carbon fixation. Observations of Trichodesmium when coupled with a numerical advection model indicate that Trichodesmium communities can remain viable for >3.5 months at temperatures lower than previously expected. The results suggest that Clade IV Trichodesmium occupies a different niche to other Trichodesmium species, and is a cold- or low-light-adapted variant.
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12
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Chiu CH, Lozier M, Bayleyegn T, Tait K, Barreau T, Copan L, Roisman R, Jackson R, Smorodinsky S, Kreutzer R, Yip F, Wolkin A. Geothermal Gases--Community Experiences, Perceptions, and Exposures in Northern California. J Environ Health 2015; 78:14-21. [PMID: 26738314 PMCID: PMC6570403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Lake County, California, is in a high geothermal-activity area. Over the past 30 years, the city of Clearlake has reported health effects and building evacuations related to geothermal venting. Previous investigations in Clearlake revealed hydrogen sulfide at levels known to cause health effects and methane at levels that can cause explosion risks. The authors conducted an investigation in multiple cities and towns in Lake County to understand better the risk of geothermal venting to the community. They conducted household surveys and outdoor air sampling of hydrogen sulfide and methane and found community members were aware of geothermal venting and some expressed concerns. The authors did not, however, find hydrogen sulfide above the California Environmental Protection Agency air quality standard of 30 parts per billion over one hour or methane above explosive thresholds. The authors recommend improving risk communication, continuing to monitor geothermal gas effects on the community, and using community reports and complaints to monitor and document geothermal venting incidents.
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Affiliation(s)
- Cindy H. Chiu
- Epidemic Intelligence Service, Centers for Disease Control and Prevention
- Health Studies Branch, National Center for Environmental Health, Centers for Disease Control and Prevention
| | - M. Lozier
- Epidemic Intelligence Service, Centers for Disease Control and Prevention
- Air Pollution and Respiratory Health Branch, National Center for Environmental Health, Centers for Disease Control and Prevention
| | - T. Bayleyegn
- Health Studies Branch, National Center for Environmental Health, Centers for Disease Control and Prevention
| | - K. Tait
- Lake County Public Health Division
| | - T. Barreau
- California Department of Public Health, Division of Environmental and Occupational Disease Control
| | - L. Copan
- California Department of Public Health, Division of Environmental and Occupational Disease Control
| | - R. Roisman
- California Department of Public Health, Division of Environmental and Occupational Disease Control
| | - R. Jackson
- California Department of Public Health, Division of Environmental and Occupational Disease Control
| | - S. Smorodinsky
- California Department of Public Health, Division of Environmental and Occupational Disease Control
| | - R. Kreutzer
- California Department of Public Health, Division of Environmental and Occupational Disease Control
| | - F. Yip
- Air Pollution and Respiratory Health Branch, National Center for Environmental Health, Centers for Disease Control and Prevention
| | - A. Wolkin
- Health Studies Branch, National Center for Environmental Health, Centers for Disease Control and Prevention
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13
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Tait K, Beesley A, Findlay HS, McNeill CL, Widdicombe S. Elevated CO2induces a bloom of microphytobenthos within a shell gravel mesocosm. FEMS Microbiol Ecol 2015. [DOI: 10.1093/femsec/fiv092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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14
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Ransome E, Rowley SJ, Thomas S, Tait K, Munn CB. Disturbance to conserved bacterial communities in the cold-water gorgonian coral Eunicella verrucosa. FEMS Microbiol Ecol 2014; 90:404-16. [PMID: 25078065 DOI: 10.1111/1574-6941.12398] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 07/12/2014] [Accepted: 07/27/2014] [Indexed: 01/24/2023] Open
Abstract
The bacterial communities associated with healthy and diseased colonies of the cold-water gorgonian coral Eunicella verrucosa at three sites off the south-west coast of England were compared using denaturing gradient gel electrophoresis (DGGE) and clone libraries. Significant differences in community structure between healthy and diseased samples were discovered, as were differences in the level of disturbance to these communities at each site; this correlated with depth and sediment load. The majority of cloned sequences from healthy coral tissue affiliated with the Gammaproteobacteria. The stability of the bacterial community and dominance of specific genera found across visibly healthy colonies suggest the presence of a specific microbial community. Affiliations included a high proportion of Endozoicomonas sequences, which were most similar to sequences found in tropical corals. This genus has been found in a number of invertebrates and is suggested to have a role in coral health and in the metabolisation of dimethylsulfoniopropionate (DMSP) produced by zooxanthellae. However, screening of colonies for the presence of zooxanthellae produced a negative result. Diseased colonies showed a decrease in affiliated clones and an increase in clones related to potentially harmful/transient microorganisms but no increase in a particular pathogen. This study demonstrates that a better understanding of these bacterial communities, the factors that affect them and their role in coral health and disease will be of critical importance in predicting future threats to temperate gorgonian communities.
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Affiliation(s)
- Emma Ransome
- Plymouth Marine Laboratory, Plymouth, UK; School of Marine Science and Engineering, Plymouth University, Plymouth, UK; Smithsonian National Museum of Natural History, Washington, DC, USA
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15
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Twigg MS, Tait K, Williams P, Atkinson S, Cámara M. Interference with the germination and growth of Ulva zoospores by quorum-sensing molecules from Ulva-associated epiphytic bacteria. Environ Microbiol 2014; 16. [PMID: 23879807 PMCID: PMC4304359 DOI: 10.1111/emi.12203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ulva zoospores preferentially settle on N-acylhomoserine lactone (AHL) producing marine bacterial biofilms. To investigate whether AHL signal molecules also affect the success and rate of zoospore germination in addition to zoospore attraction, the epiphytic bacteria associated with mature Ulva linza were characterized and bacterial isolates representative of this community tested for the ability to produce AHLs. Two of these AHL-producing isolates, Sulfitobacter spp. 376 and Shewanella spp. 79, were transformed with plasmids expressing the Bacillus spp. AHL lactonase gene aiiA to generate AHL-deficient variants. The germination and growth of U. linza zoospores was studied in the presence of these AHL-deficient strains and their AHL-producing counterparts. This revealed that the AHLs produced by Sulfitobacter spp. and Shewanella spp. or the bacterial products they regulate have a negative impact on both zoospore germination and the early growth of the Ulva germling. Further experiments with Escherichia coli biofilms expressing recombinant AHL synthases and synthetic AHLs provide data to demonstrate that zoospores germinated and grown in the absence of AHLs were significantly longer than those germinated in the presence of AHLs. These results reveal an additional role for AHLs per se in the interactive relationships between marine bacteria and Ulva zoospores.
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Affiliation(s)
- Matthew S Twigg
- School of Molecular Medical Sciences, Centre for Biomedical Sciences, University of NottinghamNG7 2RD, Nottingham, UK,Plymouth Marine LaboratoryProspect Place, Plymouth, PL1 3DH, UK
| | - Karen Tait
- Plymouth Marine LaboratoryProspect Place, Plymouth, PL1 3DH, UK,
*For correspondence. E-mail ; Tel. (+44) (0)1752 633100; Fax (+44) (0)1752 633101
| | - Paul Williams
- School of Molecular Medical Sciences, Centre for Biomedical Sciences, University of NottinghamNG7 2RD, Nottingham, UK
| | - Steve Atkinson
- School of Molecular Medical Sciences, Centre for Biomedical Sciences, University of NottinghamNG7 2RD, Nottingham, UK
| | - Miguel Cámara
- School of Molecular Medical Sciences, Centre for Biomedical Sciences, University of NottinghamNG7 2RD, Nottingham, UK
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16
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Laverock B, Tait K, Gilbert JA, Osborn AM, Widdicombe S. Impacts of bioturbation on temporal variation in bacterial and archaeal nitrogen-cycling gene abundance in coastal sediments. Environ Microbiol Rep 2014; 6:113-21. [PMID: 24596269 PMCID: PMC4208606 DOI: 10.1111/1758-2229.12115] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/11/2013] [Indexed: 05/13/2023]
Abstract
In marine environments, macrofauna living in or on the sediment surface may alter the structure, diversity and function of benthic microbial communities. In particular, microbial nitrogen (N)-cycling processes may be enhanced by the activity of large bioturbating organisms. Here, we study the effect of the burrowing mud shrimp Upogebia deltaura upon temporal variation in the abundance of genes representing key N-cycling functional guilds. The abundance of bacterial genes representing different N-cycling guilds displayed different temporal patterns in burrow sediments in comparison with surface sediments, suggesting that the burrow provides a unique environment where bacterial gene abundances are influenced directly by macrofaunal activity. In contrast, the abundances of archaeal ammonia oxidizers varied temporally but were not affected by bioturbation, indicating differential responses between bacterial and archaeal ammonia oxidizers to environmental physicochemical controls. This study highlights the importance of bioturbation as a control over the temporal variation in nitrogen-cycling microbial community dynamics within coastal sediments.
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Affiliation(s)
- B Laverock
- Plymouth Marine LaboratoryProspect Place, Plymouth, PL1 3DH, UK
- Department of Animal and Plant Sciences, University of SheffieldSheffield, S10 2TN, UK
- School of Plant Biology and the UWA Oceans Institute, University of Western AustraliaCrawley, WA, 6009, Australia
| | - K Tait
- Plymouth Marine LaboratoryProspect Place, Plymouth, PL1 3DH, UK
| | - J A Gilbert
- Argonne National Laboratory, Institute of Genomic and Systems Biology9700 South Cass Avenue, Argonne, IL, 60439, USA
- Department of Ecology and Evolution, University of Chicago5640 South Ellis Avenue, Chicago, IL, 60637, USA
| | - A M Osborn
- Department of Animal and Plant Sciences, University of SheffieldSheffield, S10 2TN, UK
- Department of Biological Sciences, University of HullHull, HU6 7RX, UK
- School of Life Sciences, University of Lincoln, Brayford PoolLincoln, LN6 7TS, UK
| | - S Widdicombe
- Plymouth Marine LaboratoryProspect Place, Plymouth, PL1 3DH, UK
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17
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Hogg-Kollars S, Al Dulaimi D, Tait K, Rostami K. Type 1 diabetes mellitus and gluten induced disorders. Gastroenterol Hepatol Bed Bench 2014; 7:189-97. [PMID: 25289132 PMCID: PMC4185872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 08/24/2014] [Indexed: 11/25/2022]
Abstract
Over the last five decades the association between coeliac disease and other autoimmune disorders such as autoimmune thyroid disease or diabetes mellitus type 1 has been well established through many studies and to this day is subject to on-going clinical and scientific investigation worldwide. While no link has been established between celiac disease and type-2 diabetes mellitus, coeliac disease is common in patients with type 1 diabetes. The improvement of symptoms in patients with both conditions through dietary intervention, in the form of a gluten free diet, has been widely described within the literature. Our objectives were to review and synthesise the current knowledge on the nutritional treatment for patients with both conditions.
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Affiliation(s)
| | - David Al Dulaimi
- Department of Gastroenterology, Alexandra Hospital, Redditch, UK
| | - Karen Tait
- Department of General Medicine, Alexandra Hospital, Redditch, UK
| | - Kamran Rostami
- Institute of Health & Society, University of Worcester, UK
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18
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Tait K, Laverock B, Shaw J, Somerfield PJ, Widdicombe S. Minor impact of ocean acidification to the composition of the active microbial community in an Arctic sediment. Environ Microbiol Rep 2013; 5:851-860. [PMID: 24249294 DOI: 10.1111/1758-2229.12087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 07/10/2013] [Indexed: 06/02/2023]
Abstract
Effects of ocean acidification on the composition of the active bacterial and archaeal community within Arctic surface sediment was analysed in detail using 16S rRNA 454 pyrosequencing. Intact sediment cores were collected and exposed to one of five different pCO(2) concentrations [380 (present day), 540, 750, 1120 and 3000 μatm] and RNA extracted after a period of 14 days exposure. Measurements of diversity and multivariate similarity indicated very little difference between pCO(2) treatments. Only when the highest and lowest pCO(2) treatments were compared were significant differences evident, namely increases in the abundance of operational taxonomic units most closely related to the Halobacteria and differences to the presence/absence structure of the Planctomycetes. The relative abundance of members of the classes Planctomycetacia and Nitrospira increased with increasing pCO(2) concentration, indicating that these groups may be able to take advantage of changing pH or pCO(2) conditions. The modest response of the active microbial communities associated with these sediments may be due to the low and fluctuating pore-water pH already experienced by sediment microbes, a result of the pH buffering capacity of marine sediments, or due to currently unknown factors. Further research is required to fully understand the impact of elevated CO(2) on sediment physicochemical parameters, biogeochemistry and microbial community dynamics.
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Affiliation(s)
- Karen Tait
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK
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19
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Ransome E, Munn CB, Halliday N, Cámara M, Tait K. Diverse profiles ofN-acyl-homoserine lactone molecules found in cnidarians. FEMS Microbiol Ecol 2013; 87:315-29. [DOI: 10.1111/1574-6941.12226] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 09/06/2013] [Accepted: 09/15/2013] [Indexed: 12/11/2022] Open
Affiliation(s)
- Emma Ransome
- Plymouth Marine Laboratory; Plymouth Devon UK
- School of Marine Science and Engineering; Plymouth University; Plymouth UK
| | - Colin B. Munn
- School of Marine Science and Engineering; Plymouth University; Plymouth UK
| | - Nigel Halliday
- School of Molecular Medical Sciences; Centre for Biomolecular Sciences; University of Nottingham; Nottingham UK
| | - Miguel Cámara
- School of Molecular Medical Sciences; Centre for Biomolecular Sciences; University of Nottingham; Nottingham UK
| | - Karen Tait
- Plymouth Marine Laboratory; Plymouth Devon UK
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20
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Russell BD, Connell SD, Findlay HS, Tait K, Widdicombe S, Mieszkowska N. Ocean acidification and rising temperatures may increase biofilm primary productivity but decrease grazer consumption. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120438. [PMID: 23980241 DOI: 10.1098/rstb.2012.0438] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Climate change may cause ecosystems to become trophically restructured as a result of primary producers and consumers responding differently to increasing CO2 and temperature. This study used an integrative approach using a controlled microcosm experiment to investigate the combined effects of CO2 and temperature on key components of the intertidal system in the UK, biofilms and their consumers (Littorina littorea). In addition, to identify whether pre-exposure to experimental conditions can alter experimental outcomes we explicitly tested for differential effects on L. littorea pre-exposed to experimental conditions for two weeks and five months. In contrast to predictions based on metabolic theory, the combination of elevated temperature and CO2 over a five-week period caused a decrease in the amount of primary productivity consumed by grazers, while the abundance of biofilms increased. However, long-term pre-exposure to experimental conditions (five months) altered this effect, with grazing rates in these animals being greater than in animals exposed only for two weeks. We suggest that the structure of future ecosystems may not be predictable using short-term laboratory experiments alone owing to potentially confounding effects of exposure time and effects of being held in an artificial environment over prolonged time periods. A combination of laboratory (physiology responses) and large, long-term experiments (ecosystem responses) may therefore be necessary to adequately predict the complex and interactive effects of climate change as organisms may acclimate to conditions over the longer term.
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Affiliation(s)
- Bayden D Russell
- Southern Seas Ecology Laboratories, School of Earth and Environmental Sciences, University of Adelaide, South Australia 5005, Australia.
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21
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Laverock B, Kitidis V, Tait K, Gilbert JA, Osborn AM, Widdicombe S. Bioturbation determines the response of benthic ammonia-oxidizing microorganisms to ocean acidification. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120441. [PMID: 23980243 PMCID: PMC3758174 DOI: 10.1098/rstb.2012.0441] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ocean acidification (OA), caused by the dissolution of increasing concentrations of atmospheric carbon dioxide (CO2) in seawater, is projected to cause significant changes to marine ecology and biogeochemistry. Potential impacts on the microbially driven cycling of nitrogen are of particular concern. Specifically, under seawater pH levels approximating future OA scenarios, rates of ammonia oxidation (the rate-limiting first step of the nitrification pathway) have been shown to dramatically decrease in seawater, but not in underlying sediments. However, no prior study has considered the interactive effects of microbial ammonia oxidation and macrofaunal bioturbation activity, which can enhance nitrogen transformation rates. Using experimental mesocosms, we investigated the responses to OA of ammonia oxidizing microorganisms inhabiting surface sediments and sediments within burrow walls of the mud shrimp Upogebia deltaura. Seawater was acidified to one of four target pH values (pHT 7.90, 7.70, 7.35 and 6.80) in comparison with a control (pHT 8.10). At pHT 8.10, ammonia oxidation rates in burrow wall sediments were, on average, fivefold greater than in surface sediments. However, at all acidified pH values (pH ≤ 7.90), ammonia oxidation rates in burrow sediments were significantly inhibited (by 79-97%; p < 0.01), whereas rates in surface sediments were unaffected. Both bacterial and archaeal abundances increased significantly as pHT declined; by contrast, relative abundances of bacterial and archaeal ammonia oxidation (amoA) genes did not vary. This research suggests that OA could cause substantial reductions in total benthic ammonia oxidation rates in coastal bioturbated sediments, leading to corresponding changes in coupled nitrogen cycling between the benthic and pelagic realms.
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Affiliation(s)
- B Laverock
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
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22
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Twigg MS, Tait K, Williams P, Atkinson S, Cámara M. Interference with the germination and growth of
U
lva
zoospores by quorum‐sensing molecules from
U
lva
‐associated epiphytic bacteria. Environ Microbiol 2013; 16:445-53. [DOI: 10.1111/1462-2920.12203] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 06/22/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Matthew S. Twigg
- School of Molecular Medical Sciences Centre for Biomedical Sciences University of Nottingham NG7 2RD Nottingham UK
- Plymouth Marine Laboratory Prospect Place Plymouth PL1 3DH UK
| | - Karen Tait
- Plymouth Marine Laboratory Prospect Place Plymouth PL1 3DH UK
| | - Paul Williams
- School of Molecular Medical Sciences Centre for Biomedical Sciences University of Nottingham NG7 2RD Nottingham UK
| | - Steve Atkinson
- School of Molecular Medical Sciences Centre for Biomedical Sciences University of Nottingham NG7 2RD Nottingham UK
| | - Miguel Cámara
- School of Molecular Medical Sciences Centre for Biomedical Sciences University of Nottingham NG7 2RD Nottingham UK
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23
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Tait K, Havenhand J. Investigating a possible role for the bacterial signal molecules N-acylhomoserine lactones in Balanus improvisus cyprid settlement. Mol Ecol 2013; 22:2588-602. [PMID: 23506419 DOI: 10.1111/mec.12273] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 01/18/2013] [Accepted: 01/25/2013] [Indexed: 01/29/2023]
Abstract
Increased settlement on bacterial biofilms has been demonstrated for a number of marine invertebrate larvae, but the nature of the cue(s) responsible is not well understood. We tested the hypothesis that the bay barnacle Balanus improvisus utilizes the bacterial signal molecules N-acylhomoserine lactones (AHLs) as a cue for the selection of sites for permanent attachment. Single species biofilms of the AHL-producing bacteria Vibrio anguillarum, Aeromonas hydrophila and Sulfitobacter sp. BR1 were attractive to settling cypris larvae of B. improvisus. However, when AHL production was inactivated, either by mutation of the AHL synthetic genes or by expression of an AHL-degrading gene (aiiA), the ability of the bacteria to attract cyprids was abolished. In addition, cyprids actively explored biofilms of E. coli expressing the recombinant AHL synthase genes luxI from Vibrio fischeri (3-oxo-C6-HSL), rhlI from Pseudomonas aeruginosa (C4-HSL/C6-HSL), vanI from V. anguillarum (3-oxo-C10-HSL) and sulI from Sulfitobacter sp. BR1 (C4-HSL, 3-hydroxy-C6-HSL, C8-HSL and 3-hydroxy-C10-HSL), but not E. coli that did not produce AHLs. Finally, synthetic AHLs (C8-HSL, 3-oxo-C10-HSL and C12-HSL) at concentrations similar to those found within natural biofilms (5 μm) resulted in increased cyprid settlement. Thus, B. improvisus cypris exploration of and settlement on biofilms appears to be mediated by AHL-signalling bacteria in the laboratory. This adds to our understanding of how quorum sensing inhibition may be used as for biofouling control. Nonetheless, the significance of our results for larvae settling naturally in the field, and the mechanisms that underlay the observed responses to AHLs, is as yet unknown.
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Affiliation(s)
- Karen Tait
- Plymouth Marine Laboratory, Plymouth, UK.
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24
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Tommonaro G, Abbamondi GR, Iodice C, Tait K, De Rosa S. Diketopiperazines produced by the halophilic archaeon, Haloterrigena hispanica, activate AHL bioreporters. Microb Ecol 2012; 63:490-495. [PMID: 22109096 DOI: 10.1007/s00248-011-9980-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 11/04/2011] [Indexed: 05/31/2023]
Abstract
The generic term "quorum sensing" has been adopted to describe the bacterial cell-to-cell communication mechanism which coordinates gene expression when the population has reached a high cell density. Quorum sensing depends on the synthesis of small molecules that diffuse in and out of bacterial cells. There are few reports about this mechanism in Archaea. We report the isolation and chemical characterization of small molecules belonging to class of diketopiperazines (DKPs) in Haloterrigena hispanica, an extremely halophilic archaeon. One of the DKPs isolated, the compound cyclo-(L-prolyl-L-valine) activated N-acyl homoserine lactone (AHL) bioreporters, indicating that Archaea may have the ability to interact with AHL-producing bacteria within mixed communities.
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Affiliation(s)
- Giuseppina Tommonaro
- Institute of Biomolecular Chemistry, CNR-National Research Council of Italy, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy.
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25
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Cámara F, Sokolova E, Hawthorne FC, Rowe R, Grice J, Tait K. Veblenite: a new Ti-silicate related to HOH structures. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311083632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Temperton B, Thomas S, Tait K, Parry H, Emery M, Allen M, Quinn J, Macgrath J, Gilbert J. Permanent draft genome sequence of Vibrio tubiashii strain NCIMB 1337 (ATCC19106). Stand Genomic Sci 2011; 4:183-90. [PMID: 21677855 PMCID: PMC3111986 DOI: 10.4056/sigs.1654066] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Vibrio tubiashii NCIMB 1337 is a major and increasingly prevalent pathogen of bivalve mollusks, and shares a close phylogenetic relationship with both V. orientalis and V. coralliilyticus. It is a Gram-negative, curved rod-shaped bacterium, originally isolated from a moribund juvenile oyster, and is both oxidase and catalase positive. It is capable of growth under both aerobic and anaerobic conditions. Here we describe the features of this organism, together with the draft genome and annotation. The genome is 5,353,266 bp long, consisting of two chromosomes, and contains 4,864 protein-coding and 86 RNA genes.
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Shapiro M, Fritz C, Tait K, Paddock C, Nicholson W, Abramowicz K, Karpathy S, Dasch G, Sumner J, Adem P, Scott J, Padgett K, Zaki S, Eremeeva M. Rickettsia364D: A Newly Recognized Cause of Eschar‐Associated Illness in California. Clin Infect Dis 2010; 50:541-8. [DOI: 10.1086/649926] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Abstract
Corals are inhabited by complex communities of microbes that affect their growth and survival. Several studies suggest that coral disease may be attributed to the success of vibrios in out-competing other bacteria in the mucus and tissues of corals. Vibrios utilize a variety of quorum sensing (QS) signal molecules to regulate processes that could be used to colonize corals during adverse environmental conditions. We therefore screened a range of Vibrios isolated from a variety of healthy and diseased corals, for the production of the QS signal molecules, N-acylhomoserine lactones (AHLs) and the AI-2 (autoinducer-2) small furanone signal molecule. All 29 strains examined activated the AI-2 biosensor, but only 17 activated an AHL biosensor. Using reverse phase thin-layer chromatography, we showed that the effect of temperature on AHL production varied considerably among the isolates. For the first time, the QS inhibition by Vibrio harveyi is reported. This only occurred at higher temperatures and does not appear to be due to degradation of AHLs. The large diversity of vibrios and the different effects of temperature on signal production may partly explain the complexity of coral-associated community changes in response to environmental factors.
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Affiliation(s)
- Karen Tait
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK. School of Biological Sciences, Plymouth University, Plymouth, PL4 8AA, UK. Department of Genetics, Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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Tait K, Williamson H, Atkinson S, Williams P, Cámara M, Joint I. Turnover of quorum sensing signal molecules modulates cross-kingdom signalling. Environ Microbiol 2009; 11:1792-802. [PMID: 19508552 DOI: 10.1111/j.1462-2920.2009.01904.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
N-acylhomoserine lactone (AHL) quorum-sensing molecules modulate the swimming behaviour of zoospores of the macroalga Ulva to facilitate the location of bacterial biofilms. Here we show that the intertidal surfaces colonized by Ulva are dominated by Alphaproteobacteria, particularly the Rhodobacteraceae family, and the Bacteroidetes family Flavobacteriaceae, and that this diverse assemblage both produces and degrades AHLs. N-acylhomoserine lactones could also be extracted from the surfaces of pebbles recovered from intertidal rock-pools. Bacteria representative of this assemblage were isolated and tested for the production and degradation of AHLs, and for their ability to modulate zoospore settlement at different biofilm densities. Of particular interest was a Shewanella sp. This strain produced three major AHLs (OC4, OC10 and OC12) in the late exponential phase, but the longer-chain AHLs were rapidly degraded in the stationary phase. Degradation occurred via both lactonase and amidase activity. A close relationship was found between AHL synthesis and Ulva zoospore settlement. The Shewanella isolate also interfered with AHL production by a Sulfitobacter isolate and its ability to enhance zoospore settlement in a polymicrobial biofilm. This influence on the attachment of Ulva zoospores suggests that AHL-degrading strains can affect bacterial community behaviour by interfering with quorum sensing between neighbouring bacteria. More importantly, these interactions may exert wider ecological effects across different kingdoms.
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Affiliation(s)
- Karen Tait
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK.
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Joint I, Tait K, Wheeler G. Cross-kingdom signalling: exploitation of bacterial quorum sensing molecules by the green seaweed Ulva. Philos Trans R Soc Lond B Biol Sci 2007; 362:1223--33. [PMID: 17360272 PMCID: PMC2435585 DOI: 10.1098/rstb.2007.2047] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The green seaweed Ulva has been shown to detect signal molecules produced by bacteria. Biofilms that release N-acylhomoserine lactones (AHLs) attract zoospores--the motile reproductive stages of Ulva. The evidence for AHL involvement is based on several independent lines of evidence, including the observation that zoospores are attracted to wild-type bacteria that produce AHLs but are not attracted to mutants that do not produce signal molecules. Synthetic AHL also attracts zoospores and the attraction is lost in the presence of autoinducer inactivation (AiiA) protein. The mechanism of attraction is not chemotactic but involves chemokinesis. When zoospores detect AHLs, the swimming rate is reduced and this results in accumulation of cells at the source of the AHL. It has been demonstrated that the detection of AHLs results in calcium influx into the zoospore. This is the first example of a calcium signalling event in a eukaryote in response to bacterial quorum sensing molecules. The role of AHLs in the ecology of Ulva is discussed. It is probable that AHLs act as cues for the settlement of zoospores, rather than being directly involved as a signalling mechanism.
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Affiliation(s)
- Ian Joint
- Plymouth Marine Laboratory, The Hoe, Plymouth, UK.
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Wheeler GL, Tait K, Taylor A, Brownlee C, Joint I. Acyl-homoserine lactones modulate the settlement rate of zoospores of the marine alga Ulva intestinalis via a novel chemokinetic mechanism. Plant Cell Environ 2006; 29:608-18. [PMID: 17080611 DOI: 10.1111/j.1365-3040.2005.01440.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Bacteria utilize quorum sensing to regulate the expression of cell density-dependant phenotypes such as biofilm formation and virulence. Zoospores of the marine alga Ulva intestinalis exploit the acyl-homoserine lactone (AHL) quorum sensing system to identify bacterial biofilms for preferential settlement. Here, we demonstrate that AHLs act as strong chemoattractants for Ulva zoospores. Chemoattraction does not involve a chemotactic orientation towards the AHL source. Instead, it occurs through a chemokinesis in which zoospore swimming speed is rapidly decreased in the presence of AHLs. The chemoresponse to AHLs was dependant on the nature of the acyl side chain, with N-(3-oxododecanoyl)-homoserine lactone (30-C12-HSL) being the most effective signal molecule. Mean zoospore swimming speed decreased more rapidly over wild-type biofilms of the marine bacteria Vibrio anguillarum relative to biofilms of the vanM mutant, in which AHL synthesis is disrupted. These data implicate a role for AHL-mediated chemokinesis in the location and preferential settlement of Ulva zoospores on marine bacterial assemblages. Exposure to AHLs did not inhibit the negative phototaxis of Ulva zoospores, indicating that chemoattraction to bacterial biofilms does not preclude the response to a light stimulus in substrate location.
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Affiliation(s)
- Glen L Wheeler
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK.
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Tait K, Joint I, Daykin M, Milton DL, Williams P, Cámara M. Disruption of quorum sensing in seawater abolishes attraction of zoospores of the green alga Ulva to bacterial biofilms. Environ Microbiol 2005; 7:229-40. [PMID: 15658990 DOI: 10.1111/j.1462-2920.2004.00706.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Zoospores of the eukaryotic green seaweed Ulva respond to bacterial N-acylhomoserine lactone (AHL) quorum sensing signal molecules for the selection of surface sites for permanent attachment. In this study we have investigated the production and destruction of AHLs in biofilms of the AHL-producing marine bacterium, Vibrio anguillarum and their stability in seawater. While wild type V. anguillarum NB10 was a strong attractor of zoospores, inactivation of AHL production in this strain by either expressing the recombinant Bacillus lactonase coding gene aiiA, or by mutating the AHL biosynthetic genes, resulted in the abolition of zoospore attraction. In seawater, with a pH of 8.2, the degradation of AHL molecules was temperature-dependent, indicating that the AHLs produced by marine bacterial biofilms have short half-lives. The Ulva zoospores sensed a range of different AHL molecules and in particular more zoospores settled on surfaces releasing AHLs with longer (>six carbons) N-linked acyl chains. However, this finding is likely to be influenced by the differential diffusion rates of AHLs from the experimental surface matrix. Molecules with longer N-acyl chains, such as N-(3-oxodecanoyl)- L-homoserine lactone, diffused more slowly than those with shorter N-acyl chains such as N-(3-hydroxy-hexanoyl)- L-homoserine lactone. Image analysis using GFP-tagged V. anguillarum biofilms revealed that spores settle directly on bacterial cells and in particular on microcolonies which we show are sites of concentrated AHL production.
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Affiliation(s)
- Karen Tait
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK.
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Abstract
Biofilms present complex assemblies of micro-organisms attached to surfaces. they are dynamic structures in which various metabolic activities and interactions between the component cells occur. When phage come in contact with biofilms, further interactions occur dependent on the susceptibility of the biofilm bacteria to phage and to the availability of receptor sites. If the phage also possess polysaccharide-degrading enzymes, or if considerable cell lysis is effected by the phage, the integrity of the biofilm may rapidly be destroyed. Alternatively, coexistence between phage and host bacteria within the biofilm may develop. Although phage have been proposed as a means of destroying or controlling biofilms, the technology for this has not yet been successfully developed.
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Affiliation(s)
- Ian W Sutherland
- Institute of Cell and Molecular Biology, University of Edinburgh, UK.
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Affiliation(s)
- Ian Joint
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK.
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Abstract
AIMS The objective of this study was to investigate the antagonistic interactions between bacteriocin-producing enteric bacteria in dual species biofilms and the interspecies interactions correlated with sensitivity to biocides. METHODS AND RESULTS When compared with their single species counterparts, the dual species biofilms formed by bacteriocin-producing strains exhibited a decrease in biofilm size and an increase in sensitivity to the antimicrobial agents hypochlorite, triclosan and benzalkonium chloride. The five dual species biofilms studied all resulted in biofilms containing a mixture of the two strains. This was attributed to the spatial distribution of cells within the biofilm, with each strain forming its own microcolonies. The production of a bacteriocin also gave a strain a competitive advantage when interacting with a bacteriocin-sensitive strain within a biofilm, both in gaining a foothold in a new environment and in preventing the colonization of a potential competitor into a pre-established biofilm. CONCLUSIONS It was concluded that bacteriocins might be used specifically for interacting with competing strains within a biofilm, as opposed to a planktonic, environment. SIGNIFICANCE AND IMPACT OF THE STUDY Unlike planktonically grown bacteriocin-producing populations, where one strain will always be out-competed, bacteriocin-producing and bacteriocin-sensitive strains can coexist in biofilm communities, clearly demonstrating major differences between biofilm and planktonic competition. This paper highlights the importance of bacteriocin production in the development of biofilm communities.
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Affiliation(s)
- K Tait
- Institute of Cell and Molecular Biology, Kings Buildings, Edinburgh University, Edinburgh, UK
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Callstrom MR, Johnson CD, Fletcher JG, Reed JE, Ahlquist DA, Harmsen WS, Tait K, Wilson LA, Corcoran KE. CT colonography without cathartic preparation: feasibility study. Radiology 2001; 219:693-8. [PMID: 11376256 DOI: 10.1148/radiology.219.3.r01jn22693] [Citation(s) in RCA: 203] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To evaluate methods for contrast material labeling of stool in the unprepared colon for computed tomographic (CT) colonography and to determine their sensitivity for polyp detection. MATERIALS AND METHODS Fifty-six patients with suspected or known polyps were assigned to five groups. Two to seven doses of 225 mL of dilute contrast material were orally administered during 24 or 48 hours. Transverse CT images were assessed for effectiveness of stool labeling. Colonoscopy was performed in all patients and was the standard. Two radiologists blinded to prior imaging and colonoscopic results assessed polyp detection. RESULTS For each group, average stool labeling scores and ranges were as follows: 24 hour two dose, 16% and 8%-21%; 24 hour five dose, 53% and 27%-66%; 48 hour four dose, 38% and 22%-48%; 48 hour six dose, 68% and 54%-77%; and 48 hour seven dose, 88% and 75%-98%. Sensitivity for the two radiologists for the identification of patients with polyps 1 cm or larger for each group was as follows: 24 hour two dose, 50% and 67%; 24 hour five dose, 100% and 100%; 48 hour four dose, 58% and 75%; 48 hour six dose, 56% and 67%; and 48 hour seven dose, 100% and 80%. CONCLUSION Ingestion of contrast material adequately labels stool for lesion identification; a 48-hour lead time and multiple doses of contrast material are required. Sensitivity for polyp detection in patients with adequate stool labeling approaches the sensitivity for polyp detection in prepared colons.
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Affiliation(s)
- M R Callstrom
- Department of Diagnostic Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
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Abstract
This is a report of a study of the representations and strategies for addition, used by a sample of 55 children in years 1, 2 and 3 in three schools in Brisbane. Children were presented with operations represented in symbols and asked to choose how to solve the task and explain their procedures as they worked. The teachers were interviewed to determine the representations that they were introducing. The results show a general developmental sequence from use of objects, to use of counting, to mental calculations using knowledge of number facts and place value. The results are discussed from the perspective of the demand that the procedures might make on children's information processing capacity. We suggest that some of the difficulties occur because teachers introduce procedures that are recommended in curriculum documents without being aware of the cognitive load that they impose.
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Affiliation(s)
- G M Boulton-Lewis
- School of Learning and Development, Faculty of Education, Queensland University of Technology, Australia
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Abstract
The fundamental principles of industrial hygiene are based upon the recognition, evaluation, and control of workplace hazards. Occupational safety and health professionals (e.g., industrial hygienists) perform this task by assessing numerous complex factors. In many situations industrial hygienists are not available; therefore, an expert system has been developed to assist the performance of workplace exposure assessments (WEAs). The Workplace Exposure Assessment Expert System (WORKSPERT) evaluates various hazardous substances, workplace conditions, and worker exposures for designated homogeneous exposure groups (HEGs). The three major components of WORKSPERT (i.e., substance, workplace, and exposure factors) are described by 27 multiple attribute variables. An air monitoring program (AMP) may be recommended for each HEG based upon the WEA. The AMP provides recommendations for an appropriate sampling strategy, sampling duration, multiple substance exposures, and number of samples to be obtained in the future. The use of WORKSPERT or other expert systems should never supersede the judgment of occupational safety and health professionals. However, WORKSPERT can be a valuable tool when used by knowledgeable, qualified technical professionals (e.g., safety and health specialists, chemists, engineers, and toxicologists) who understand the specific substance, workplace, and exposure factors for designated HEGs. WORKSPERT allows these people to benefit from the expertise of an industrial hygienist by performing systematic evaluations and obtaining recommendations for corrective actions or an AMP. The use of WORKSPERT to perform WEAs promotes the protection of workers from hazardous substances and assists compliance with occupational safety and health regulations. It also facilitates the communication of substance hazards, workplace controls, and worker exposures in a succinct manner.
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Affiliation(s)
- K Tait
- Pfizer Inc., New York, NY 10017
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Davidson RC, Lewis E, Daehler D, Tait K. Perinephric abscess and chronic low back pain. J Fam Pract 1982; 15:1059-1070. [PMID: 6216300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Abstract
A low density barium sulfate mixture has been specially formulated and routinely used in over 800 abdominal computer assisted tomography scans over the past 3 years.
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Tait K, Winslow G. Beyond consent--the ethics of decision-making in emergency medicine. West J Med 1977; 126:156-9. [PMID: 847978 PMCID: PMC1237490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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