Academic literature on the topic 'Planktonic microbes'
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Journal articles on the topic "Planktonic microbes"
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Cermeño, Pedro. "Marine planktonic microbes survived climatic instabilities in the past." Proceedings of the Royal Society B: Biological Sciences 279, no. 1728 (July 20, 2011): 474–79. http://dx.doi.org/10.1098/rspb.2011.1151.
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In the geological past, changes in climate and tectonic activity are thought to have spurred the tempo of evolutionary change among major taxonomic groups of plants and animals. However, the extent to which these historical contingencies increased the risk of extinction of microbial plankton species remains largely unknown. Here, I analyse fossil records of marine planktonic diatoms and calcareous nannoplankton over the past 65 million years from the world oceans and show that the probability of species' extinction is not correlated with secular changes in climatic instability. Further supporting these results, analyses of genera survivorship curves based on fossil data concurred with the predictions of a birth–death model that simulates the extinction of genera through time assuming stochastically constant rates of speciation and extinction. However, my results also show that these marine microbes responded to exceptional climatic contingencies in a manner that appears to have promoted net diversification. These results highlight the ability of marine planktonic microbes to survive climatic instabilities in the geological past, and point to different mechanisms underlying the processes of speciation and extinction in these micro-organisms.
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Li, William K. W., Robert A. Andersen, Dian J. Gifford, Lewis S. Incze, Jennifer L. Martin, Cynthia H. Pilskaln, Juliette N. Rooney-Varga, Michael E. Sieracki, William H. Wilson, and Nicholas H. Wolff. "Planktonic Microbes in the Gulf of Maine Area." PLoS ONE 6, no. 6 (June 15, 2011): e20981. http://dx.doi.org/10.1371/journal.pone.0020981.
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Khatun, Santona, Tomoya Iwata, Hisaya Kojima, Manabu Fukui, Takuya Aoki, Seito Mochizuki, Azusa Naito, Ai Kobayashi, and Ryo Uzawa. "Aerobic methane production by planktonic microbes in lakes." Science of The Total Environment 696 (December 2019): 133916. http://dx.doi.org/10.1016/j.scitotenv.2019.133916.
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Schiraldi, Alberto. "Growth and Decay of a Planktonic Microbial Culture." International Journal of Microbiology 2020 (January 24, 2020): 1–8. http://dx.doi.org/10.1155/2020/4186468.
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The paper shows that the phenomenological trends of both growth and decay of a microbial population in a given medium are easily reproducible with simple equations that allow gathering the experimental data (plate counts) related to different microbial species, in different mediums and even at different temperatures, in a single master plot. The guideline of the proposed approach is that microbes and surrounding medium form a system where they affect each other and that the so-called “growth curve” is just the phenomenological appearance of such interaction. The whole system (cells and medium) changes following a definite pathway described as the evolution of a “virtual” microbial population in planktonic conditions. The proposed equations come from the assumption of a duplication mechanism with a variable generation time for the growth and of an exponential-like decline with a linear increase of the rate for the decay. The intermediate phase between growth and decay is a time span during which growth and death counterbalance each other and age differences within the virtual cell population tend to level off. The proposed approach does not provide an a priori description of this phase but allows the fit of the whole evolution trend of a microbial culture whenever the experimental data are available. Deviations of such a trend concern microbes able to form spores, modify their metabolism, or express phenotypic heterogeneity, to counterbalance adverse medium conditions.
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Robertson, Emma J., and Arturo Casadevall. "Antibody-Mediated Immobilization of Cryptococcus neoformans Promotes Biofilm Formation." Applied and Environmental Microbiology 75, no. 8 (February 27, 2009): 2528–33. http://dx.doi.org/10.1128/aem.02846-08.
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ABSTRACT Most microbes, including the fungal pathogen Cryptococcus neoformans, can grow as biofilms. Biofilms confer upon microbes a range of characteristics, including an ability to colonize materials such as shunts and catheters and increased resistance to antibiotics. Here, we provide evidence that coating surfaces with a monoclonal antibody to glucuronoxylomannan, the major component of the fungal capsular polysaccharide, immobilizes cryptococcal cells to a surface support and, subsequently, promotes biofilm formation. We used time-lapse microscopy to visualize the growth of cryptococcal biofilms, generating the first movies of fungal biofilm growth. We show that when fungal cells are immobilized using surface-attached specific antibody to the capsule, the initial stages of biofilm formation are significantly faster than those on surfaces with no antibody coating or surfaces coated with unspecific monoclonal antibody. Time-lapse microscopy revealed that biofilm growth was a dynamic process in which cells shuffled position during budding and was accompanied by emergence of planktonic variant cells that left the attached biofilm community. The planktonic variant cells exhibited mobility, presumably by Brownian motion. Our results indicate that microbial immobilization by antibody capture hastens biofilm formation and suggest that antibody coating of medical devices with immunoglobulins must exclude binding to common pathogenic microbes and the possibility that this effect could be exploited in industrial microbiology.
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Sherr, Evelyn B., and Barry F. Sherr. "Planktonic microbes: Tiny cells at the base of the ocean's food webs." Trends in Ecology & Evolution 6, no. 2 (February 1991): 50–54. http://dx.doi.org/10.1016/0169-5347(91)90122-e.
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Asma, Syeda Tasmia, Kálmán Imre, Adriana Morar, Mirela Imre, Ulas Acaroz, Syed Rizwan Ali Shah, Syed Zajif Hussain, et al. "Natural Strategies as Potential Weapons against Bacterial Biofilms." Life 12, no. 10 (October 17, 2022): 1618. http://dx.doi.org/10.3390/life12101618.
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Microbial biofilm is an aggregation of microbial species that are either attached to surfaces or organized into an extracellular matrix. Microbes in the form of biofilms are highly resistant to several antimicrobials compared to planktonic microbial cells. Their resistance developing ability is one of the major root causes of antibiotic resistance in health sectors. Therefore, effective antibiofilm compounds are required to treat biofilm-associated health issues. The awareness of biofilm properties, formation, and resistance mechanisms facilitate researchers to design and develop combating strategies. This review highlights biofilm formation, composition, major stability parameters, resistance mechanisms, pathogenicity, combating strategies, and effective biofilm-controlling compounds. The naturally derived products, particularly plants, have demonstrated significant medicinal properties, producing them a practical approach for controlling biofilm-producing microbes. Despite providing effective antibiofilm activities, the plant-derived antimicrobial compounds may face the limitations of less bioavailability and low concentration of bioactive molecules. The microbes-derived and the phytonanotechnology-based antibiofilm compounds are emerging as an effective approach to inhibit and eliminate the biofilm-producing microbes.
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Villa Martín, Paula, Aleš Buček, Thomas Bourguignon, and Simone Pigolotti. "Ocean currents promote rare species diversity in protists." Science Advances 6, no. 29 (July 2020): eaaz9037. http://dx.doi.org/10.1126/sciadv.aaz9037.
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Oceans host communities of plankton composed of relatively few abundant species and many rare species. The number of rare protist species in these communities, as estimated in metagenomic studies, decays as a steep power law of their abundance. The ecological factors at the origin of this pattern remain elusive. We propose that chaotic advection by oceanic currents affects biodiversity patterns of rare species. To test this hypothesis, we introduce a spatially explicit coalescence model that reconstructs the species diversity of a sample of water. Our model predicts, in the presence of chaotic advection, a steeper power law decay of the species abundance distribution and a steeper increase of the number of observed species with sample size. A comparison of metagenomic studies of planktonic protist communities in oceans and in lakes quantitatively confirms our prediction. Our results support that oceanic currents positively affect the diversity of rare aquatic microbes.
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Badica, P., N. D. Batalu, M. C. Chifiriuc, M. Burdusel, M. A. Grigoroscuta, G. Aldica, I. Pasuk, et al. "MgB2 powders and bioevaluation of their interaction with planktonic microbes, biofilms, and tumor cells." Journal of Materials Research and Technology 12 (May 2021): 2168–84. http://dx.doi.org/10.1016/j.jmrt.2021.04.003.
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Bester, Elanna, Elizabeth A. Edwards, and Gideon M. Wolfaardt. "Planktonic cell yield is linked to biofilm development." Canadian Journal of Microbiology 55, no. 10 (October 2009): 1195–206. http://dx.doi.org/10.1139/w09-075.
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We report on the ability of surface-associated microbes to produce and release single planktonic cells to the bulk liquid as early as 6 h after attachment, with pure culture and mixed-species biofilms yielding up to ~1 × 106 cells/cm2 of attachment area per hour to the effluent after 24 h. Planktonic cell production typically increased as the biofilm developed and levelled off after the biofilm reached steady-state dimensions. Microscopic observations of continuous-flow cultured biofilms revealed independent cell movement within the biofilm microenvironment compared with flow-dependent movement of mostly single cells in the bulk-liquid phase. These results indicate that the prevailing concept of detachment occurring only after the biofilm has matured is incomplete. Instead, we show that biofilms yield cells to the environment soon after initial surface contact; the extent of this yield is dependent on biofilm development, which in turn is influenced by environmental parameters such as bulk-liquid flow rates and nutrient availability. The observation that biofilms yield significant numbers of cells throughout development should lead to a greater understanding of pathogen dissemination, biofouling of products or facilities, and the role that biofilms play in microbial proliferation in the environment.
Dissertations / Theses on the topic "Planktonic microbes"
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Burd, Catherine Louise. "Bioavailability of nitrogen, phosphorus, iron and cobalt to surface water planktonic microbes in the low latitude Atlantic Ocean." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/427042/.
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The effects on bacterioplankton of very low concentrations of nitrogen and phosphorus/iron in the Atlantic were investigated using shipboard enrichment experiments. In the North Atlantic gyre, bacterioplankton abundance and amino acid uptake increased upon combined addition of ammonium and phosphate (9-42% and 120-880% increase, respectively). Outside the gyre, the requirement for phosphate additions was reduced. In the South Atlantic, ammonium additions generally caused an increase in bacterioplankton abundance (10-32% after 48 h) and amino acid uptake (20-300%), particularly in the gyre centre. Conversely, iron additions showed a negligible response. These results contribute towards understanding the effect of low nutrient concentrations on bacterioplankton. Reduced abundance or metabolic activity of bacterioplankton due to low nutrient concentrations may impact marine primary production and carbon fluxes, which is a particular concern due to the expansion of oligotrophic gyres as a result of climate change. Iron and cobalt are essential micronutrients that are susceptible to forming particulate/insoluble species (e.g. via adsorption, oxidation, precipitation). These species can be lost from the surface ocean, thus reducing nutrient bioavailability. Therefore, mechanisms affecting their formation were also investigated. Cell surface iron adsorption was measured in the South Atlantic, with highest levels occurring in the gyre (~180-300 zmol Fe/cell, verses ~3-155 zmol Fe/cell in productive waters). This was hypothesised to be due to low ambient iron in the gyre, resulting in a larger free cell surface area for iron binding. Particulate cobalt formation was enhanced (>150%) in the presence of Aurantimonas (a manganese-oxidising bacteria), was generally elevated under higher manganese concentrations (e.g. ~13-60% increase upon adding MnCl2 to manganese-poor cultures), but was slightly reduced in the presence of nickel (6.2±7.4% decrease) or copper (7.4±12.2% decrease). These results further understanding of factors influencing micronutrient speciation, which is especially important considering potential changes to ocean biogeochemistry as a result of anthropogenic activity.
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Vincent, Flora. "Diatom interactions in the open ocean : from the global patterns to the single cell." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB094/document.
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Les diatomées sont des micro-algues unicellulaires, qui jouent un rôle primordial dans l’eco-système marin. En effet, elles sont responsables de 20% de l’activité photosynthétique sur Terre, et sont à la base de la chaîne alimentaire marine, toujours plus menacée par le changement climatique. Les diatomées établissent diverses interactions microbiennes avec des organismes issus de l’ensemble de l’arbre du vivant, à travers des méchanismes complexes tels que la symbiose, le parasitisme ou la compétition. L’objectif de ma thèse a été de comprendre comment ces interactions structurent la communauté du plancton, à grande échelle spatiale. Pour ce faire, j’ai développé de nouvelles approches basées sur le jeu de données inédit de Tara Océans, une expédition mondiale qui a exploré la diversité et les fonctions des microbes marins, en récoltant plus de 40.000 échantillons à travers 210 sites autour du monde. Grâce à l’analyse de réseaux de co-occurrence microbiens, je montre d’une part que les diatomées agissent comme des « ségrégateurs répulsifs » à l’échelle globale, en particulier envers les organismes potentiellement dangeureux tels que les prédateurs et les parasites, et d’autre part que la co-occurrence des espèces ne s’explique qu’en minorité par les facteurs environnementaux. Grâce à la richesse des données Tara Océans, j’ai par ailleurs permis la charactérisation d’une interaction biotique impliquant une diatomée et un cilié hétérotrophe à l’échelle de l’eco-système, illustrant de surcroît le succès des approches dirigées par les données. Dans l’ensemble, ma thèse contribue à notre compréhension des interactions biotiques impliquant les diatomées, de l’échelle globale à la cellule uniqueDiatoms are unicellular photosynthetic microeukaryotes that play a critical role in the functioning of marine ecosystems. They are responsible for 20% of global photosynthesis on Earth and lie at the base of marine food webs, ever more threatened by climate change.Diatoms establish microbial interactions with numerous organisms across the whole tree of life, through complex mechanisms including symbiosis, parasitism and competition. The goal of my thesis was to understand how those biotic interactions structure the planktonic community at large spatial scales, by using new approaches based on the unprecedented Tara Oceans dataset, a unique and worldwide circumnavigation that collected over 40.000 samples across 210 sites to explore the diversity and functions of marine microbes. Through the analysis of microbial association networks, I show that diatoms act as repulsive segregators in the ocean, in particular towards potentially harmful organisms such as predators as well as parasites, and that species co-occurrence is driven by environmental factors in a minority of cases. By leveraging the singularity of the Tara Oceans data, I provide a comprehensive characterization of a prevalent biotic interaction between a diatom and heterotrophic ciliates at large spatial scale, illustrating the success of data-driven research. Overall, my thesis contributes to our understanding of diatom biotic interactions, from the global patterns to the single cell
Books on the topic "Planktonic microbes"
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Sheppard, Charles R. C., Simon K. Davy, Graham M. Pilling, and Nicholas A. J. Graham. Microbial, microalgal and planktonic reef life. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198787341.003.0005.
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Microbes, including bacteria, archaea, viruses, fungi, protozoans and microalgae, are the most abundant and arguably the most important members of coral reef communities. They occur in the water column and sediment, and in association with other reef organisms. This chapter describes the abundance, diversity, function and productivity of microbes, with an emphasis on free-living types. They are key to recycling and retention of organic matter via the ‘microbial loop’, and are an important food source for larger reef organisms. The metazoan zooplankton are also described, including larvae of most reef invertebrates and fish. They are described in terms of their duration in the plankton, their settlement behaviour (e.g. that of coral larvae), their daily migration patterns and their role as a food source for larger organisms. Their importance for inter-reef connectivity is discussed.
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Sheppard, Charles. 5. Microbial and planktonic engines of the reef. Oxford University Press, 2014. http://dx.doi.org/10.1093/actrade/9780199682775.003.0005.
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Symbiotic algae are a crucial source of fuel for the reef, via corals and others, but how is the food and energy from the corals transferred to other parts of the ecosystem to support the huge abundance and diversity seen there? ‘Microbial and planktonic engines of the reef’ describes the filter feeding—extracting particles from the water—of the large proportion of reef animals. These particles consist of plankton, microbes, bacteria, viruses, and zooplankton. Sponges also display microbial symbiotic connections with algae and cyanobacteria that is a key component of material and energy transfer. The productivity from seaweeds on which numerous species of herbivorous fish and sea urchins graze is also important.
Book chapters on the topic "Planktonic microbes"
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Reynolds, Colin S. "Successional Change in the Planktonic Vegetation: Species, Structures, Scales." In Molecular Ecology of Aquatic Microbes, 115–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-79923-5_7.
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Fuhrman, Jed A., and David A. Caron. "Heterotrophic Planktonic Microbes: Virus, Bacteria, Archaea, and Protozoa." In Manual of Environmental Microbiology, 4.2.2–1–4.2.2–34. Washington, DC, USA: ASM Press, 2015. http://dx.doi.org/10.1128/9781555818821.ch4.2.2.
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Pinel-Alloul, Bernadette, and Anas Ghadouani. "Spatial Heterogeneity Of Planktonic Microorganisms In Aquatic Systems." In The Spatial Distribution of Microbes in the Environment, 203–310. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6216-2_8.
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Veintramuthu, Sankar, and Selliamman Ravi Mahipriya. "Approaches to Enhance Therapeutic Activity of Drugs against Bacterial Biofilms." In Bacterial Biofilms [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.104470.
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Biofilm may be a consortium of microbial species where the cells of microbes attach to both life form and inanimate surfaces inside a self-made matrix of extracellular polymeric substance (EPS). Biofilm matrix surrounding the polymicrobial environment makes them highly resistant to harsh conditions and antibacterial treatments. The two significant factors that differentiate planktonic from biofilm resident microbes are EPS containing a variety of macromolecules and a diffusible molecule for transferring signals known as quorum sensing (QS). Against this backdrop of microbial resistance and cell signaling, different approaches have been developed to interfere with the specific mechanisms of intracellular and extracellular targets that include herbal active compounds and synthetic nanoparticles. This chapter outlines the features of biofilm development and the approaches with the evidence that can be incorporated into clinical usage.
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Celiksoy, Vildan, and Charles M. Heard. "Antimicrobial Potential of Pomegranate Extracts." In Pomegranate. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.95796.
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The search for plant extracts with efficacious antimicrobial activity remains important, partly due to fears of the side effects associated with conventional antibiotics and to counter the emergence of resistant microorganisms. Pomegranate extracts have been used for millennia for their anti-infective properties, with activity more recently being attributed to its rich composition of ellagitannins and other secondary polyphenolic compounds. This chapter highlights the growing number of publications that have probed the activity of pomegranate extracts against microbes. Research generally supports folklore claims and has shown that pomegranate extracts possess unusual and potent broad-spectrum activities against Gram-positive and Gram-negative bacteria (planktonic and biofilm), fungi, viruses and parasites. Possible pathways/mechanisms of antimicrobial activity of pomegranate extracts are discussed and enhancement/potentiation of such activity using metal ions considered.
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Barbosa, Ana. "Seasonal and Interannual Variability of Planktonic Microbes in a Mesotidal Coastal Lagoon (Ria Formosa, SE Portugal)." In Coastal Lagoons, 335–66. CRC Press, 2010. http://dx.doi.org/10.1201/ebk1420088304-c14.
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"Plankton (phytoplankton, zooplankton, microbes and viruses." In The Second World Ocean Assessment, 115–40. United Nations, 2021. http://dx.doi.org/10.18356/9789216040062c010.
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Hobbie, John E. "Long-Term Ecological Research in the Arctic: Where Science Never Sleeps." In Long-Term Ecological Research. Oxford University Press, 2016. http://dx.doi.org/10.1093/oso/9780199380213.003.0015.
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When the Arctic (ARC) Long-Term Ecological Research (LTER) project began, I was an aquatic ecologist with experience in managing large projects in freshwaters and estuaries and a specialization in microbes. This project, which studies lakes, streams, and tundras, has greatly increased my breadth as an ecologist and allowed me to take part in terrestrial modeling, microbial studies in streams, and the role of soil mycorrhizal fungi in providing nutrients to many species of plants. As a mentor to several postdoctoral fellows, my LTER research has enabled me to learn about other fields such as the application of molecular biology to microbial ecology. The Arctic LTER project data, the long-term field experiments, and the facilities available at the University of Alaska field station brought me in contact with ecologists from many countries. One result of this association with experts was my coauthorship of a book on Arctic natural history aimed at communicating scientific knowledge to scientists and the general public unfamiliar with the Arctic (Huryn and Hobbie 2012). I have always collaborated extensively with many scientists and encouraged collaboration as the best way to carry out ecosystem research. The Arctic LTER project brought many opportunities to broaden the scope of my collaboration to include terrestrial ecologists and microbiologists. My PhD research was about year-round primary productivity of an Arctic lake but while on a postdoctoral fellowship at Uppsala University, Sweden, I switched to an emphasis on bacterial uptake kinetics in lakes. The techniques I helped develop in freshwater worked in the ocean and estuaries too (Hobbie and Williams 1984). In addition we developed the epifluorescence method for quantifying the abundance of planktonic bacteria. Our paper (Hobbie, Daley, and Jasper 1977) finally convinced oceanographers that bacteria are abundant (at 10⁹ per liter) and important. Recently, I have used my understanding of kinetics of uptake to analyze microbial activity in the soil. My Arctic expertise led to leadership of the aquatic part of the International Biological Program (IBP) at Barrow, Alaska, beginning in 1970. We (28 scientists, graduate students, and postdoctoral fellows) studied shallow ponds to quantify the carbon, nitrogen, and phosphorus cycles.
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Weinbauer, Markus G., and Xavier Mari. "Effects of Ocean Acidification on the Diversity and Activity of Heterotrophic Marine Microorganisms." In Ocean Acidification. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199591091.003.0010.
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Microbe-mediated processes are crucial for biogeochemical cycles and the functioning of marine ecosystems (Azam and Malfatti 2007 ). If these processes are affected by ocean acidification, major consequences can be expected for the functioning of the global ocean and the systems that it influences, such as the atmosphere. In contrast to phytoplankton, which have been relatively well studied (see Chapter 6), there is comparatively little information on the effect of ocean acidification on heterotrophic microorganisms. Two reviews on the potential effects of ocean acidification on microbial plankton have recently been published (Liu et al. 2010 ; Joint et al. 2011) . In a recent perspective paper, Joint et al. (2011) concluded that marine microbes possess the flexibility to accommodate pH change and that major changes in marine biogeochemical processes that are driven by microorganisms are unlikely. Narrative reviews, which look at some of the relevant literature, are potentially biased and could lead to misleading conclusions (Gates 2002). Metaanalysis was developed to overcome most biases of narrative reviews. It statistically combines the results (effect size) of several studies that address a shared research hypothesis. Liu et al. (2010) used a metaanalytic approach to comprehensively review the current understanding of the effect of ocean acidification on microbes (including phytoplankton) and microbial processes, and to highlight the gaps that need to be addressed in future research. In the following, a brief digest on oceanic microbes and their role is provided for readers unfamiliar with this topic. Then the research that has been performed to assess the effects of ocean acidification on the diversity and activity of heterotrophic marine microorganisms is reviewed. Finally, scenarios are developed and potential implications are discussed. Microorganisms are defined as organisms that are microscopic, i.e. too small to be seen by the naked human eye, and mostly comprise single-celled organisms. Viruses are sometimes also included in this definition but it is hotly debated whether viruses are alive or not (Raoult and Forterre 2008). The current phylogeny considers three domains of cellular life, the Bacteria, the Archaea and the Eukarya.
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Zalasiewicz, Jan. "Gold!" In The Planet in a Pebble. Oxford University Press, 2010. http://dx.doi.org/10.1093/oso/9780199569700.003.0015.
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This is the beginning of the long goodbye to the surface realm. The flakes and grains of the pebble material are now in utter darkness (except perhaps for occasional flickers of phosphorescence from some of that microbial life), at the bottom of that deep, stagnant sea. The strata that we see in the pebble are a few centimetres thick. But now, of course, they are made of good, hard, respectable, tightly compressed rock. Back then, they made a layer of mud—waterlogged, sticky, slimy, and very likely evil-smelling mud—a quarter of a metre thick or more, that formed part of a layer on the sea floor that extended for tens of kilometres in every direction. Let us catch it at just this point in time, before it became buried by further influxes of sediment from those endless turbidity currents. The mud was full of life, particularly at the surface, most of which will have been occupied by those infinitely complex microscopic city-states that are microbial mats. But even below that, in the buried mud itself, there will have been considerable activity. In fact, as microbes are extremely good at clinging to life in all kinds of conditions, that activity was to carry on for quite some time yet. Those indefatigable microbes, though, still had to earn their keep. One way of doing that was by making use of the soft tissues of the fallen plankton, that were dismantled and recycled in the process that we call decay. Even in these anoxic conditions, where decay was slow, the magnificent, complex molecular architecture of body tissues was beginning to degrade, to transform into smaller, simpler molecules, leaving just the considerable inedible remnants that are the cases of the acritarchs and the chitinozoa, and the living quarters of the graptolites, upon which the microbes did not seem to manage to get much of a foothold (so to speak), even though they had decades and centuries in which to make the attempt. It is one thing to be occupied in this microscopic breaker’s yard, amid the wreckage of proteins, fats, and carbohydrates.
Conference papers on the topic "Planktonic microbes"
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Henoch, Charles, Charles Beauchamp, Richard Philips, Eric Dow, Gene Nuttall, and Duncan Brown. "Recent Work at the NUWC/NASA Langley Seawater Tow Tank." In SNAME 25th American Towing Tank Conference. SNAME, 1998. http://dx.doi.org/10.5957/attc-1998-027.
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The Langley seawater tow tank, located on Langley Airbase in Hampton, Virginia, was designed and built by NACA in 1931 for seaplane research and has been in various states of use since then. Since 1983, NUWC has maintained stewardship of the tank and has conducted a large number of tests there. This paper will present an overview of the facility and its capabilities as well as discuss several recent test results. The tank is reinforced concrete, 2880 feet long, 12 feet deep, and 24 feet wide, and can be filled with 5.4 million gallons of either fresh or baywater. Baywater can be filtered to 25 microns and has a salinity about half that of seawater. The carriage is powered by eight 75 hp D.C. motors with trolley style cables and can attain speeds of up to 40 knots. Power is generated by a 850 kW motor generator. Several struts exist for model towing and the carriage bas 110/120 V.A.C. and 3 phase 208 A.C. volt available power. A workshop is in the building and a variety of instrumentation and data acquisition is on hand. Unique possibilities exist at the LTT due to the organic and physical properties of seawater. For example, one of the largest ever artificial colonies of plankton was grown there. Furthermore, because of the electrical conductivity of the water, research into the control of turbulent flows by magnetohydrodynamic forces can be, and bas been, performed there. To illustrate the variety of test configurations an capabilities, results are presented from three recent test programs performed at the tank. The first will be the set-up and test results of a fully submerged axisymmetric 180 inch long cylindrical sting mounted model. The test rig will be shown including the floating swing balance which is coupled to an axial load cell. Test results will be shown for hydrodynamic resistance versus speed at zero and non-zero attack angles. The second set of results shown will be those of a towed cylindrical body equipped with remotely actuated hydrodynamic drag brakes which was released in flight an allowed to come to rest Drag measurements made at different drag brake settings and speeds will be presented as well as photographic documentation. Finally, a recent set of test results will be presented; taken on a submerged cylindrical body, strut mounted to a 6 degree of freedom load balance. Results to be presented will include force and moment measurements as a function of speed and attack angle.