Amaral-Zettler Linda A.

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Linda A.

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  • Article
    Toward interoperable bioscience data
    (Nature Publishing Group, 2012-01-27) Sansone, Susanna-Assunta ; Rocca-Serra, Philippe ; Field, Dawn ; Maguire, Eamonn ; Taylor, Chris ; Hofmann, Oliver ; Fang, Hong ; Neumann, Steffen ; Tong, Weida ; Amaral-Zettler, Linda A. ; Begley, Kimberly ; Booth, Tim ; Bougueleret, Lydie ; Burns, Gully ; Chapman, Brad ; Clark, Tim ; Coleman, Lee-Ann ; Copeland, Jay ; Das, Sudeshna ; de Daruvar, Antoine ; de Matos, Paula ; Dix, Ian ; Edmunds, Scott ; Evelo, Chris T. ; Forster, Mark K. ; Gaudet, Pascale ; Gilbert, Jack A. ; Goble, Carole ; Griffin, Julian L. ; Jacob, Daniel ; Kleinjans, Jos ; Harland, Lee ; Haug, Kenneth ; Hermjakob, Henning ; Ho Sui, Shannan J. ; Laederach, Alain ; Liang, Shaoguang ; Marshall, Stephen ; McGrath, Annette ; Merrill, Emily ; Reilly, Dorothy ; Roux, Magali ; Shamu, Caroline E. ; Shang, Catherine A. ; Steinbeck, Christoph ; Trefethen, Anne ; Williams-Jones, Bryn ; Wolstencroft, Katherine ; Xenarios, Ioannis ; Hide, Winston
    To make full use of research data, the bioscience community needs to adopt technologies and reward mechanisms that support interoperability and promote the growth of an open 'data commoning' culture. Here we describe the prerequisites for data commoning and present an established and growing ecosystem of solutions using the shared 'Investigation-Study-Assay' framework to support that vision.
  • Article
    Genomic Standards Consortium projects
    (Genomic Standards Consortium, 2014) Field, Dawn ; Sterk, Peter ; Kottmann, Renzo ; De Smet, Wim ; Amaral-Zettler, Linda A. ; Cochrane, Guy R. ; James, Cole R. ; Davies, Neil ; Dawyndt, Peter ; Garrity, George M. ; Gilbert, Jack A. ; Glockner, Frank Oliver ; Hirschman, Lynette ; Klenk, Hans-Peter ; Knight, Rob ; Kyrpides, Nikos C. ; Meyer, Folker ; Karsch-Mizrachi, Ilene ; Morrison, Norman ; Robbins, Robert J. ; San Gil, Inigo ; Sansone, Susanna-Assunta ; Schriml, Lynn M. ; Tatusova, Tatiana ; Ussery, David W. ; Yilmaz, Pelin ; White, Owen ; Wooley, John ; Caporaso, J. Gregory
    The Genomic Standards Consortium (GSC) is an open-membership community working towards the development, implementation and harmonization of standards in the field of genomics. The mission of the GSC is to improve digital descriptions of genomes, metagenomes and gene marker sequences. The GSC started in late 2005 with the defined task of establishing what is now termed the “Minimum Information about any Sequence” (MIxS) standard [1,2]. As an outgrowth of the activities surrounding the creation and implementation of the MixS standard there are now 18 projects within the GSC [3]. These efforts cover an ever widening range of standardization activities. Given the growth of projects and to promote transparency, participation and adoption the GSC has developed a “GSC Project Description Template”. A complete set of GSC Project Descriptions and the template are available on the GSC website. The GSC has an open policy of participation and continues to welcome new efforts. Any projects that facilitate the standard descriptions and exchange of data are potential candidates for inclusion under the GSC umbrella. Areas that expand the scope of the GSC are encouraged. Through these collective activities we hope to help foster the growth of the ‘bioinformatics standards’ community. For more information on the GSC and its range of projects, please see
  • Article
    Envisioning a marine biodiversity observation network
    (University of California Press, 2013-05) Duffy, J. Emmett ; Amaral-Zettler, Linda A. ; Fautin, Daphne G. ; Paulay, Gustav ; Rynearson, Tatiana A. ; Sosik, Heidi M. ; Stachowicz, John J.
    Humans depend on diverse ocean ecosystems for food, jobs, and sustained well-being, yet many stressors threaten marine life. Extensive research has demonstrated that maintaining biodiversity promotes ocean health and service provision; therefore, monitoring the status and trends of marine biodiversity is important for effective ecosystem management. However, there is no systematic sustained program for evaluating ocean biodiversity. Coordinating existing monitoring and building a proactive marine biodiversity observation network will support efficient, economical resource management and conservation and should be a high priority. A synthesis of expert opinions suggests that, to be most effective, a marine biodiversity observation network should integrate biological levels, from genes to habitats; link biodiversity observations to abiotic environmental variables; site projects to incorporate environmental forcing and biogeography; and monitor adaptively to address emerging issues. We summarize examples illustrating how to leverage existing data and infrastructure to meet these goals.
  • Article
    The biogeography of the Plastisphere : implications for policy
    (Ecological Society of America, 2015-12) Amaral-Zettler, Linda A. ; Zettler, Erik R. ; Slikas, Beth ; Boyd, Gregory D. ; Melvin, Donald W. ; Morrall, Clare E. ; Proskurowski, Giora ; Mincer, Tracy J.
    Microplastics (particles less than 5 mm) numerically dominate marine debris and occur from coastal waters to mid-ocean gyres, where surface circulation concentrates them. Given the prevalence of plastic marine debris (PMD) and the rise in plastic production, the impacts of plastic on marine ecosystems will likely increase. Microscopic life (the “Plastisphere”) thrives on these tiny floating “islands” of debris and can be transported long distances. Using next-generation DNA sequencing, we characterized bacterial communities from water and plastic samples from the North Pacific and North Atlantic subtropical gyres to determine whether the composition of different Plastisphere communities reflects their biogeographic origins. We found that these communities differed between ocean basins – and to a lesser extent between polymer types – and displayed latitudinal gradients in species richness. Our research reveals some of the impacts of microplastics on marine biodiversity, demonstrates that the effects and fate of PMD may vary considerably in different parts of the global ocean, and suggests that PMD mitigation will require regional management efforts.
  • Preprint
    Distribution and seasonal variability in the benthic eukaryotic community of Río Tinto (SW, Spain), an acidic, high metal extreme environment
    ( 2007-02-14) Aguilera, Angeles ; Zettler, Erik R. ; Gomez, Felipe ; Amaral-Zettler, Linda A. ; Rodríguez, Nuria ; Amils, Ricardo
    The eukaryotic community of Río Tinto (SW, Spain) was surveyed fall, winter, and spring through the combined use of traditional microscopy and molecular approaches including Denaturing Gradient Gel Electrophoresis (DGGE) and sequence analysis of 18S rRNA gene fragments. We compared eukaryotic assemblages of surface sediment biofilms collected in January, May and September 2002 from 13 sampling stations along the river. Physicochemical data revealed extremely acidic conditions (pH ranged from 0.9 to 2.5) with high concentrations of heavy metals including up to 20 g l-1 Fe, 317 mg l-1 Zn, 47 mg l-1 As, 42 mg l-1 Cd, and 4 mg l-1 Ni. In total, 20 taxa were identified, including members of the Bacillariophyta, Chlorophyta, and Euglenophyta phyla as well as ciliates, cercomonads, amoebae, stramenopiles, fungi, heliozoan and rotifers. In general, total cell abundances were highest in fall and spring decreasing drastically in winter and the sampling stations with the most extreme conditions showed the lowest number of cells as well as the lowest diversity. Species diversity does not vary much during the year. Only the filamentous algae showed a dramatic seasonal change almost disappearing in winter and reaching the highest biomass during the summer. PCA showed a high inverse correlation between pH and most of the heavy metals analyzed as well as Dunaliella sp., while Chlamydomonas sp. is directly related to pH during May and September. Three heavy metals (Zn, Cu and Ni) remained separate from the rest and showed an inverse correlation with most of the species analyzed except for Dunaliella sp.
  • Article
    RCN4GSC Workshop Report : managing data at the interface of biodiversity and (meta)genomics, March 2011
    (Genomic Standards Consortium, 2012-07-28) Robbins, Robert J. ; Amaral-Zettler, Linda A. ; Bik, Holly M. ; Blum, Stan D. ; Edwards, James ; Field, Dawn ; Garrity, George M. ; Gilbert, Jack A. ; Kottmann, Renzo ; Krishtalka, Leonard ; Lapp, Hilmar ; Lawrence, Carolyn ; Morrison, Norman ; O Tuama, Eamonn ; Parr, Cynthia Sims ; San Gil, Inigo ; Schindel, David ; Schriml, Lynn M. ; Vieglas, David ; Wooley, John
    Building on the planning efforts of the RCN4GSC project, a workshop was convened in San Diego to bring together experts from genomics and metagenomics, biodiversity, ecology, and bioinformatics with the charge to identify potential for positive interactions and progress, especially building on successes at establishing data standards by the GSC and by the biodiversity and ecological communities. Until recently, the contribution of microbial life to the biomass and biodiversity of the biosphere was largely overlooked (because it was resistant to systematic study). Now, emerging genomic and metagenomic tools are making investigation possible. Initial research findings suggest that major advances are in the offing. Although different research communities share some overlapping concepts and traditions, they differ significantly in sampling approaches, vocabularies and workflows. Likewise, their definitions of ‘fitness for use’ for data differ significantly, as this concept stems from the specific research questions of most importance in the different fields. Nevertheless, there is little doubt that there is much to be gained from greater coordination and integration. As a first step toward interoperability of the information systems used by the different communities, participants agreed to conduct a case study on two of the leading data standards from the two formerly disparate fields: (a) GSC’s standard checklists for genomics and metagenomics and (b) TDWG’s Darwin Core standard, used primarily in taxonomy and systematic biology.
  • Article
    Massively parallel tag sequencing reveals the complexity of anaerobic marine protistan communities
    (BioMed Central, 2009-11-03) Stoeck, Thorsten ; Behnke, Anke ; Christen, Richard ; Amaral-Zettler, Linda A. ; Rodriguez-Mora, Maria J. ; Chistoserdov, Andrei Y. ; Orsi, William D. ; Edgcomb, Virginia P.
    Recent advances in sequencing strategies make possible unprecedented depth and scale of sampling for molecular detection of microbial diversity. Two major paradigm-shifting discoveries include the detection of bacterial diversity that is one to two orders of magnitude greater than previous estimates, and the discovery of an exciting 'rare biosphere' of molecular signatures ('species') of poorly understood ecological significance. We applied a high-throughput parallel tag sequencing (454 sequencing) protocol adopted for eukaryotes to investigate protistan community complexity in two contrasting anoxic marine ecosystems (Framvaren Fjord, Norway; Cariaco deep-sea basin, Venezuela). Both sampling sites have previously been scrutinized for protistan diversity by traditional clone library construction and Sanger sequencing. By comparing these clone library data with 454 amplicon library data, we assess the efficiency of high-throughput tag sequencing strategies. We here present a novel, highly conservative bioinformatic analysis pipeline for the processing of large tag sequence data sets.The analyses of ca. 250,000 sequence reads revealed that the number of detected Operational Taxonomic Units (OTUs) far exceeded previous richness estimates from the same sites based on clone libraries and Sanger sequencing. More than 90% of this diversity was represented by OTUs with less than 10 sequence tags. We detected a substantial number of taxonomic groups like Apusozoa, Chrysomerophytes, Centroheliozoa, Eustigmatophytes, hyphochytriomycetes, Ichthyosporea, Oikomonads, Phaeothamniophytes, and rhodophytes which remained undetected by previous clone library-based diversity surveys of the sampling sites. The most important innovations in our newly developed bioinformatics pipeline employ (i) BLASTN with query parameters adjusted for highly variable domains and a complete database of public ribosomal RNA (rRNA) gene sequences for taxonomic assignments of tags; (ii) a clustering of tags at k differences (Levenshtein distance) with a newly developed algorithm enabling very fast OTU clustering for large tag sequence data sets; and (iii) a novel parsing procedure to combine the data from individual analyses. Our data highlight the magnitude of the under-sampled 'protistan gap' in the eukaryotic tree of life. This study illustrates that our current understanding of the ecological complexity of protist communities, and of the global species richness and genome diversity of protists, is severely limited. Even though 454 pyrosequencing is not a panacea, it allows for more comprehensive insights into the diversity of protistan communities, and combined with appropriate statistical tools, enables improved ecological interpretations of the data and projections of global diversity.
  • Article
    A method for selectively enriching microbial DNA from contaminating vertebrate host DNA
    (Public Library of Science, 2013-10-28) Feehery, George R. ; Yigit, Erbay ; Oyola, Samuel O. ; Langhorst, Bradley W. ; Schmidt, Victor T. ; Stewart, Fiona J. ; Dimalanta, Eileen T. ; Amaral-Zettler, Linda A. ; Davis, Theodore ; Quail, Michael A. ; Pradhan, Sriharsa
    DNA samples derived from vertebrate skin, bodily cavities and body fluids contain both host and microbial DNA; the latter often present as a minor component. Consequently, DNA sequencing of a microbiome sample frequently yields reads originating from the microbe(s) of interest, but with a vast excess of host genome-derived reads. In this study, we used a methyl-CpG binding domain (MBD) to separate methylated host DNA from microbial DNA based on differences in CpG methylation density. MBD fused to the Fc region of a human antibody (MBD-Fc) binds strongly to protein A paramagnetic beads, forming an effective one-step enrichment complex that was used to remove human or fish host DNA from bacterial and protistan DNA for subsequent sequencing and analysis. We report enrichment of DNA samples from human saliva, human blood, a mock malaria-infected blood sample and a black molly fish. When reads were mapped to reference genomes, sequence reads aligning to host genomes decreased 50-fold, while bacterial and Plasmodium DNA sequences reads increased 8–11.5-fold. The Shannon-Wiener diversity index was calculated for 149 bacterial species in saliva before and after enrichment. Unenriched saliva had an index of 4.72, while the enriched sample had an index of 4.80. The similarity of these indices demonstrates that bacterial species diversity and relative phylotype abundance remain conserved in enriched samples. Enrichment using the MBD-Fc method holds promise for targeted microbiome sequence analysis across a broad range of sample types.
  • Article
    A method for studying protistan diversity using massively parallel sequencing of V9 hypervariable regions of small-subunit ribosomal RNA genes
    (Public Library of Science, 2009-07-27) Amaral-Zettler, Linda A. ; McCliment, Elizabeth A. ; Ducklow, Hugh W. ; Huse, Susan M.
    Massively parallel pyrosequencing of amplicons from the V6 hypervariable regions of small-subunit (SSU) ribosomal RNA (rRNA) genes is commonly used to assess diversity and richness in bacterial and archaeal populations. Recent advances in pyrosequencing technology provide read lengths of up to 240 nucleotides. Amplicon pyrosequencing can now be applied to longer variable regions of the SSU rRNA gene including the V9 region in eukaryotes. We present a protocol for the amplicon pyrosequencing of V9 regions for eukaryotic environmental samples for biodiversity inventories and species richness estimation. The International Census of Marine Microbes (ICoMM) and the Microbial Inventory Research Across Diverse Aquatic Long Term Ecological Research Sites (MIRADA-LTERs) projects are already employing this protocol for tag sequencing of eukaryotic samples in a wide diversity of both marine and freshwater environments. Massively parallel pyrosequencing of eukaryotic V9 hypervariable regions of SSU rRNA genes provides a means of estimating species richness from deeply-sampled populations and for discovering novel species from the environment.
  • Article
    The coastal environment and human health : microbial indicators, pathogens, sentinels and reservoirs
    (BioMed Central, 2008-11-07) Stewart, Jill R. ; Gast, Rebecca J. ; Fujioka, Roger S. ; Solo-Gabriele, Helena M. ; Meschke, J. Scott ; Amaral-Zettler, Linda A. ; del Castillo, Erika ; Polz, Martin F. ; Collier, Tracy K. ; Strom, Mark S. ; Sinigalliano, Christopher D. ; Moeller, Peter D. R. ; Holland, A. Fredrick
    Innovative research relating oceans and human health is advancing our understanding of disease-causing organisms in coastal ecosystems. Novel techniques are elucidating the loading, transport and fate of pathogens in coastal ecosystems, and identifying sources of contamination. This research is facilitating improved risk assessments for seafood consumers and those who use the oceans for recreation. A number of challenges still remain and define future directions of research and public policy. Sample processing and molecular detection techniques need to be advanced to allow rapid and specific identification of microbes of public health concern from complex environmental samples. Water quality standards need to be updated to more accurately reflect health risks and to provide managers with improved tools for decision-making. Greater discrimination of virulent versus harmless microbes is needed to identify environmental reservoirs of pathogens and factors leading to human infections. Investigations must include examination of microbial community dynamics that may be important from a human health perspective. Further research is needed to evaluate the ecology of non-enteric water-transmitted diseases. Sentinels should also be established and monitored, providing early warning of dangers to ecosystem health. Taken together, this effort will provide more reliable information about public health risks associated with beaches and seafood consumption, and how human activities can affect their exposure to disease-causing organisms from the oceans.
  • Article
    The ecological impacts of marine debris : unraveling the demonstrated evidence from what is perceived
    (John Wiley & Sons, 2016-03-07) Rochman, Chelsea ; Browne, Mark Anthony ; Underwood, A. J. ; van Franeker, Jan A. ; Thompson, Richard C. ; Amaral-Zettler, Linda A.
    Anthropogenic debris contaminates marine habitats globally, leading to several perceived ecological impacts. Here, we critically and systematically review the literature regarding impacts of debris from several scientific fields to understand the weight of evidence regarding the ecological impacts of marine debris. We quantified perceived and demonstrated impacts across several levels of biological organization that make up the ecosystem and found 366 perceived threats of debris across all levels. Two hundred and ninety-six of these perceived threats were tested, 83% of which were demonstrated. The majority (82%) of demonstrated impacts were due to plastic, relative to other materials (e.g., metals, glass) and largely (89%) at suborganismal levels (e.g., molecular, cellular, tissue). The remaining impacts, demonstrated at higher levels of organization (i.e., death to individual organisms, changes in assemblages), were largely due to plastic marine debris (>1 mm; e.g., rope, straws, and fragments). Thus, we show evidence of ecological impacts from marine debris, but conclude that the quantity and quality of research requires improvement to allow the risk of ecological impacts of marine debris to be determined with precision. Still, our systematic review suggests that sufficient evidence exists for decision makers to begin to mitigate problematic plastic debris now, to avoid risk of irreversible harm.
  • Preprint
    Proceedings of the international workshop on Ribosomal RNA technology, April 7–9, 2008, Bremen, Germany
    ( 2008-08-07) Amaral-Zettler, Linda A. ; Peplies, Jorg ; Ramette, Alban ; Fuchs, Bernhard M. ; Ludwig, Wolfgang ; Glockner, Frank Oliver
    Thirty years have passed since Carl Woese proposed three primary domains of life based on the phylogenetic analysis of ribosomal RNA genes. Adopted by researchers worldwide, ribosomal RNA has become the “gold-standard” for molecular taxonomy, biodiversity analysis and the identification of microorganisms. The more than 700,000 rRNA sequences in public databases constitute an unprecedented hallmark of the richness of microbial biodiversity on earth. The International Workshop on Ribosomal RNA Technology convened on April 7-9, 2008 in Bremen, Germany ( to summarize the current status of the field and strategize on the best ways of proceeding on both biological and technological fronts. In five sessions, 26 leading international speakers and ~120 participants representing diverse disciplines discussed new technological approaches to address three basic ecological questions: “Who is out there?” “How many are there?” and “What are they doing?”
  • Article
    The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP) : illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing
    (Public Library of Science, 2014-06-24) Keeling, Patrick J. ; Burki, Fabien ; Wilcox, Heather M. ; Allam, Bassem ; Allen, Eric E. ; Amaral-Zettler, Linda A. ; Armbrust, E. Virginia ; Archibald, John M. ; Bharti, Arvind K. ; Bell, Callum J. ; Beszteri, Bank ; Bidle, Kay D. ; Cameron, Connor T. ; Campbell, Lisa ; Caron, David A. ; Cattolico, Rose Ann ; Collier, Jackie L. ; Coyne, Kathryn J. ; Davy, Simon K. ; Deschamps, Phillipe ; Dyhrman, Sonya T. ; Edvardsen, Bente ; Gates, Ruth D. ; Gobler, Christopher J. ; Greenwood, Spencer J. ; Guida, Stephanie M. ; Jacobi, Jennifer L. ; Jakobsen, Kjetill S. ; James, Erick R. ; Jenkins, Bethany D. ; John, Uwe ; Johnson, Matthew D. ; Juhl, Andrew R. ; Kamp, Anja ; Katz, Laura A. ; Kiene, Ronald P. ; Kudryavtsev, Alexander N. ; Leander, Brian S. ; Lin, Senjie ; Lovejoy, Connie ; Lynn, Denis ; Marchetti, Adrian ; McManus, George ; Nedelcu, Aurora M. ; Menden-Deuer, Susanne ; Miceli, Cristina ; Mock, Thomas ; Montresor, Marina ; Moran, Mary Ann ; Murray, Shauna A. ; Nadathur, Govind ; Nagai, Satoshi ; Ngam, Peter B. ; Palenik, Brian ; Pawlowski, Jan ; Petroni, Giulio ; Piganeau, Gwenael ; Posewitz, Matthew C. ; Rengefors, Karin ; Romano, Giovanna ; Rumpho, Mary E. ; Rynearson, Tatiana A. ; Schilling, Kelly B. ; Schroeder, Declan C. ; Simpson, Alastair G. B. ; Slamovits, Claudio H. ; Smith, David R. ; Smith, G. Jason ; Smith, Sarah R. ; Sosik, Heidi M. ; Stief, Peter ; Theriot, Edward ; Twary, Scott N. ; Umale, Pooja E. ; Vaulot, Daniel ; Wawrik, Boris ; Wheeler, Glen L. ; Wilson, William H. ; Xu, Yan ; Zingone, Adriana ; Worden, Alexandra Z.
    Microbial ecology is plagued by problems of an abstract nature. Cell sizes are so small and population sizes so large that both are virtually incomprehensible. Niches are so far from our everyday experience as to make their very definition elusive. Organisms that may be abundant and critical to our survival are little understood, seldom described and/or cultured, and sometimes yet to be even seen. One way to confront these problems is to use data of an even more abstract nature: molecular sequence data. Massive environmental nucleic acid sequencing, such as metagenomics or metatranscriptomics, promises functional analysis of microbial communities as a whole, without prior knowledge of which organisms are in the environment or exactly how they are interacting. But sequence-based ecological studies nearly always use a comparative approach, and that requires relevant reference sequences, which are an extremely limited resource when it comes to microbial eukaryotes. In practice, this means sequence databases need to be populated with enormous quantities of data for which we have some certainties about the source. Most important is the taxonomic identity of the organism from which a sequence is derived and as much functional identification of the encoded proteins as possible. In an ideal world, such information would be available as a large set of complete, well-curated, and annotated genomes for all the major organisms from the environment in question. Reality substantially diverges from this ideal, but at least for bacterial molecular ecology, there is a database consisting of thousands of complete genomes from a wide range of taxa, supplemented by a phylogeny-driven approach to diversifying genomics. For eukaryotes, the number of available genomes is far, far fewer, and we have relied much more heavily on random growth of sequence databases, raising the question as to whether this is fit for purpose.
  • Preprint
    Depleted dissolved organic carbon and distinct bacterial communities in the water column of a rapid-flushing coral reef ecosystem
    ( 2011-01-11) Nelson, Craig E. ; Alldredge, Alice L. ; McCliment, Elizabeth A. ; Amaral-Zettler, Linda A. ; Carlson, Craig A.
    Coral reefs are highly productive ecosystems bathed in unproductive, low-nutrient oceanic waters, where microbially-dominated food webs are supported largely by bacterioplankton recycling of dissolved compounds. Despite evidence that benthic reef organisms efficiently scavenge particulate organic matter and inorganic nutrients from advected oceanic waters, our understanding of the role of bacterioplankton and dissolved organic matter in the interaction between reefs and the surrounding ocean remains limited. Here we present the results of a four-year study conducted in a well-characterized coral reef ecosystem (Paopao Bay, Moorea, French Polynesia) where changes in bacterioplankton abundance and dissolved organic carbon (DOC) concentrations were quantified and bacterial community structure variation was examined along spatial gradients of the reef:ocean interface. Our results illustrate that the reef is consistently depleted in concentrations of both DOC and bacterioplankton relative to offshore waters (averaging 79 µmol L-1 DOC and 5.5 X 108 cells L-1 offshore and 68 µmol L-1 DOC and 3.1 X 108 cells L-1 over the reef, respectively) across a four year time period. In addition, using a suite of culture-independent measures of bacterial community structure, we found consistent differentiation of reef bacterioplankton communities from those offshore or in a nearby embayment across all taxonomic levels. Reef habitats were enriched in Gamma-, Delta-, and Beta-proteobacteria, Bacteriodetes, Actinobacteria and Firmicutes. Specific bacterial phylotypes, including members of the SAR11, SAR116, Flavobacteria, and Synechococcus clades, exhibited clear gradients in relative abundance among nearshore habitats. Our observations indicate that this reef system removes oceanic DOC and exerts selective pressures on bacterioplankton community structure on timescales approximating reef water residence times, observations which are notable both because fringing reefs do not exhibit long residence times (unlike those characteristic of atoll lagoons) and because oceanic DOC is generally recalcitrant to degradation by ambient microbial assemblages. Our findings thus have interesting implications for the role of oceanic DOM and bacterioplankton in the ecology and metabolism of reef ecosystems.
  • Article
    Prokaryotic community structure in algal photosynthetic biofilms from extreme acidic streams in Rio Tinto (Huelva, Spain)
    (Spanish Society for Microbiology (SEM), 2008-12) Souza-Egipsy, Virginia ; Gonzalez-Toril, Elena ; Zettler, Erik R. ; Amaral-Zettler, Linda A. ; Aguilera, Angeles ; Amils, Ricardo
    Four algal photosynthetic biofilms were collected from the Rio Tinto (SW Spain) at four localities: AG, Euglena and Pinnularia biofilms; ANG, Chlorella and Pinnularia biofilms; RI, Cyanidium and Dunaliella biofilms; and CEM, Cyanidium, Euglena and Pinnularia biofilms. Community composition and structure were studied by a polyphasic approach consisting of 16S rRNA analysis, scanning electron microscopy by back-scattered electron detection mode (SEM-BSE), and fluorescence in-situ hybridization (FISH). Acidophilic prokaryotes associated with algal photosynthetic biofilms included sequences related to the Alpha-, Beta-, and Gammaproteobacteria (phylum Proteobacteria) and to the phyla Nitrospira, Actinobacteria, Acidobacteria and Firmicutes. Sequences from the Archaea domain were also identified. No more than seven distinct lineages were detected in any biofilm, except for those from RI, which contained fewer groups of Bacteria. Prokaryotic communities of the thinnest algal photosynthetic biofilms (<100 μm) were more related to those in the water column, including Leptospirillum populations. In general, thick biofilms (>200 μm) generate microniches that could facilitate the development of less-adapted microorganisms (coming from the surrounding environment) to extreme conditions, thus resulting in a more diverse prokaryotic biofilm.
  • Preprint
    Culturing of the first 37:4 predominant lacustrine haptophyte : geochemical, biochemical, and genetic implications
    ( 2011-02) Toney, Jaime L. ; Theroux, Susanna ; Andersen, Robert A. ; Coleman, Annette ; Amaral-Zettler, Linda A. ; Huang, Yongsong
    Long chain alkenones (LCAs) are potential biomarkers for quantitative paleotemperature reconstructions from lacustrine environments. However, progress in this area has been severely hindered by the lack of culture studies of haptophytes responsible for alkenone distributions in lake sediments: the predominance of C37:4 LCA. Here we report the first enrichment culturing of a novel haptophyte phylotype (Hap-A) from Lake George, ND that produces predominantly C37:4-LCA. Hap-A was enriched from its resting phase collected from deep sediments rather than from water column samples. In contrast, enrichments from near surface water yielded a different haptophyte phylotype (Hap-B), closely related to Chrysotila lamellosa and Pseudoisochrysis paradoxa, which does not display C37:4-LCA predominance (similar enrichments have been reported previously). The LCA profile in sediments resembles that of Hap-A enrichments, suggesting that Hap-A is the dominant alkenone producer of the sedimentary LCAs. In enrichments, excess lighting appeared to be crucial for triggering blooms of Hap-A. Both and indices show a linear relationship with temperature for Hap-A in enrichments, but the relationship appears to be dependent on the growth stage. Based on 18S rRNA gene analyses, several lakes from the Northern Great Plains, as well as Pyramid Lake, NV and Tso Ur, Tibetan Plateau, China contain the same two haptophyte phylotypes. The Great Plains lakes show the Hap-A-type LCA distribution, whereas Pyramid and Tso Ur show the Hap-B type distribution. Waters of the Great Plain lakes are dominated by sulfate, whereas those Pyramid and Tso Ur are dominated by carbonate, suggesting that the sulfate to carbonate ratio may be a determining factor for the competitiveness of the Hap-A and Hap-B phylotypes in natural settings.
  • Preprint
    Impacts of Hurricanes Katrina and Rita on the microbial landscape of the New Orleans area
    ( 2007-03-20) Sinigalliano, Christopher D. ; Gidley, M. L. ; Shibata, T. ; Whitman, D. ; Dixon, T. H. ; Laws, Edward A. ; Hou, A. ; Bachoon, D. ; Brand, Larry E. ; Amaral-Zettler, Linda A. ; Gast, Rebecca J. ; Steward, Grieg F. ; Nigro, Olivia D. ; Fujioka, Roger S. ; Betancourt, W. Q. ; Vithanage, G. ; Mathews, J. ; Fleming, Lora E. ; Solo-Gabriele, Helena M.
    Floodwaters in New Orleans from Hurricanes Katrina and Rita were observed to contain high levels of fecal indicator bacteria and microbial pathogens, generating concern about long-term impacts of these floodwaters on the sediment and water quality of the New Orleans area and Lake Pontchartrain. We show here that fecal indicator microbe concentrations in offshore waters from Lake Pontchartrain returned to prehurricane concentrations within 2 months of the flooding induced by these hurricanes. Vibrio and Legionella species within the lake were more abundant in samples collected shortly after the floodwaters had receded compared with samples taken within the subsequent 3 months; no evidence of a long-term hurricane-induced algal bloom was observed. Giardia and Cryptosporidium were detected in canal waters. Elevated levels of fecal indicator bacteria observed in sediment could not be solely attributed to impacts from floodwaters, as both flooded and nonflooded areas exhibited elevated levels of fecal indicator bacteria. Evidence from measurements of Bifidobacterium and bacterial diversity analysis suggest that the fecal indicator bacteria observed in the sediment were from human fecal sources. Epidemiologic studies are highly recommended to evaluate the human health effects of the sediments deposited by the floodwaters.
  • Article
    The ocean sampling day consortium
    (BioMed Central, 2015-06-19) Kopf, Anna ; Bicak, Mesude ; Kottmann, Renzo ; Schnetzer, Julia ; Kostadinov, Ivaylo ; Lehmann, Katja ; Fernandez-Guerra, Antonio ; Jeanthon, Christian ; Rahav, Eyal ; Ullrich, Matthias S. ; Wichels, Antje ; Gerdts, Gunnar ; Polymenakou, Paraskevi ; Kotoulas, Georgios ; Siam, Rania ; Abdallah, Rehab Z. ; Sonnenschein, Eva C. ; Cariou, Thierry ; O’Gara, Fergal ; Jackson, Stephen ; Orlic, Sandi ; Steinke, Michael ; Busch, Julia ; Duarte, Bernardo ; Caçador, Isabel ; Canning-Clode, Joao ; Bobrova, Oleksandra ; Marteinsson, Viggo ; Reynisson, Eyjolfur ; Loureiro, Clara Magalhaes ; Luna, Gian Marco ; Quero, Grazia Marina ; Loscher, Carolin R. ; Kremp, Anke ; DeLorenzo, Marie E. ; Øvreås, Lise ; Tolman, Jennifer ; LaRoche, Julie ; Penna, Antonella ; Frischer, Marc ; Davis, Timothy ; Katherine, Barker ; Meyer, Christopher P. ; Ramos, Sandra ; Magalhaes, Catarina ; Jude-Lemeilleur, Florence ; Aguirre-Macedo, Ma Leopoldina ; Wang, Shiao ; Poulton, Nicole ; Jones, Scott ; Collin, Rachel ; Fuhrman, Jed A. ; Conan, Pascal ; Alonso, Cecilia ; Stambler, Noga ; Goodwin, Kelly ; Yakimov, Michail M. ; Baltar, Federico ; Bodrossy, Levente ; Van De Kamp, Jodie ; Frampton, Dion M. F. ; Ostrowski, Martin ; Van Ruth, Paul ; Malthouse, Paul ; Claus, Simon ; Deneudt, Klaas ; Mortelmans, Jonas ; Pitois, Sophie ; Wallom, David ; Salter, Ian ; Costa, Rodrigo ; Schroeder, Declan C. ; Kandil, Mahrous M. ; Amaral, Valentina ; Biancalana, Florencia ; Santana, Rafael ; Pedrotti, Maria Luiza ; Yoshida, Takashi ; Ogata, Hiroyuki ; Ingleton, Timothy ; Munnik, Kate ; Rodriguez-Ezpeleta, Naiara ; Berteaux-Lecellier, Veronique ; Wecker, Patricia ; Cancio, Ibon ; Vaulot, Daniel ; Bienhold, Christina ; Ghazal, Hassan ; Chaouni, Bouchra ; Essayeh, Soumya ; Ettamimi, Sara ; Zaid, El Houcine ; Boukhatem, Noureddine ; Bouali, Abderrahim ; Chahboune, Rajaa ; Barrijal, Said ; Timinouni, Mohammed ; El Otmani, Fatima ; Bennani, Mohamed ; Mea, Marianna ; Todorova, Nadezhda ; Karamfilov, Ventzislav ; ten Hoopen, Petra ; Cochrane, Guy R. ; L’Haridon, Stephane ; Bizsel, Kemal Can ; Vezzi, Alessandro ; Lauro, Federico M. ; Martin, Patrick ; Jensen, Rachelle M. ; Hinks, Jamie ; Gebbels, Susan ; Rosselli, Riccardo ; De Pascale, Fabio ; Schiavon, Riccardo ; dos Santos, Antonina ; Villar, Emilie ; Pesant, Stephane ; Cataletto, Bruno ; Malfatti, Francesca ; Edirisinghe, Ranjith ; Herrera Silveira, Jorge A. ; Barbier, Michele ; Turk, Valentina ; Tinta, Tinkara ; Fuller, Wayne J. ; Salihoglu, Ilkay ; Serakinci, Nedime ; Ergoren, Mahmut Cerkez ; Bresnan, Eileen ; Iriberri, Juan ; Fronth Nyhus, Paul Anders ; Bente, Edvardsen ; Karlsen, Hans Erik ; Golyshin, Peter N. ; Gasol, Josep M. ; Moncheva, Snejana ; Dzhembekova, Nina ; Johnson, Zackary ; Sinigalliano, Christopher D. ; Gidley, Maribeth Louise ; Zingone, Adriana ; Danovaro, Roberto ; Tsiamis, Georgios ; Clark, Melody S. ; Costa, Ana Cristina ; El Bour, Monia ; Martins, Ana M. ; Collins, R. Eric ; Ducluzeau, Anne-Lise ; Martinez, Jonathan ; Costello, Mark J. ; Amaral-Zettler, Linda A. ; Gilbert, Jack A. ; Davies, Neil ; Field, Dawn ; Glockner, Frank Oliver
    Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.
  • Article
    The Genomic Standards Consortium
    (Public Library of Science, 2011-06-21) Field, Dawn ; Amaral-Zettler, Linda A. ; Cochrane, Guy R. ; Cole, James R. ; Dawyndt, Peter ; Garrity, George M. ; Gilbert, Jack A. ; Glockner, Frank Oliver ; Hirschman, Lynette ; Karsch-Mizrachi, Ilene ; Klenk, Hans-Peter ; Knight, Rob ; Kottmann, Renzo ; Kyrpides, Nikos C. ; Meyer, Folker ; San Gil, Inigo ; Sansone, Susanna-Assunta ; Schriml, Lynn M. ; Sterk, Peter ; Tatusova, Tatiana ; Ussery, David W. ; White, Owen ; Wooley, John
    A vast and rich body of information has grown up as a result of the world's enthusiasm for 'omics technologies. Finding ways to describe and make available this information that maximise its usefulness has become a major effort across the 'omics world. At the heart of this effort is the Genomic Standards Consortium (GSC), an open-membership organization that drives community-based standardization activities, Here we provide a short history of the GSC, provide an overview of its range of current activities, and make a call for the scientific community to join forces to improve the quality and quantity of contextual information about our public collections of genomes, metagenomes, and marker gene sequences.
  • Article
    Alkenone producers inferred from well-preserved 18S rDNA in Greenland lake sediments
    (American Geophysical Union, 2006-09-19) D'Andrea, William J. ; Lage, Melissa ; Martiny, Jennifer B. H. ; Laatsch, Abby D. ; Amaral-Zettler, Linda A. ; Sogin, Mitchell L. ; Huang, Yongsong
    The 18S ribosomal DNA (rDNA) sequences of haptophyte algae were successfully amplified using the polymerase chain reaction (PCR) from water filtrate, surface sediments, and a late-Holocene sediment sample (∼1000 years old) from a group of lakes in the Søndre Strømfjord region of west Greenland. The DNA of the algal primary producer is extremely well preserved in the laminated lake sediments which have been deposited in cold (1°–2°C), anoxic, and sulphidic bottom water. Phylogenetic analyses of the Greenland haptophyte rDNA sequences suggest that alkenones in the Greenland lake sediments are produced by haptophyte algae of the class Prymnesiophyceae. The 18S rDNA sequences from the Greenland samples cluster within a distinct phylotype, differing from both marine haptophytes and from those reported previously from Ace Lake, Antarctica. The similarity of haptophyte rDNA sequences among all samples in this study suggests a single alkenone-based temperature calibration may be applied to these lakes for at least the past 1000 years. These sedimentary archives hold great promise for high-resolution, alkenone-based paleotemperature reconstruction of southern west Greenland, a region sensitive to atmospheric-oceanic climate phenomena such as the North Atlantic Oscillation (NAO).