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  • Arsenic methylation by marine cyanobacteria Prochlorococcus and Synechococcus

    Creator:
    Lee, Mikaela
    Abstract:
    Our experiments aimed to investigate responses of the marine cyanobacteria Prochlorococcus and Synechococcus to toxic arsenic species, such as arsenate, and to understand cellular mechanisms that contribute to arsenic tolerance. We used two strains of Prochlorococcus, a high-light adapted MED4 and low-light adapted MIT9313, both axenic, for cultivation experiments. For...
    Resource Type:
    Honors College Thesis
    Full Text:
    . . Abstract approved:_____________________________________________________ Stephen Giovannoni Our

  • Outliers: The Unusual Characteristics of Marine Carbon-Oxidizing Bacterial Cells Adapted to Oligotrophic Conditions

    Creator:
    Noell, Stephen E.
    Abstract:
    Oligotrophic bacteria are adapted to low nutrient concentrations. As most of the ocean is oligotrophic (low in nutrients), oligotrophic bacteria thrive in the ocean and make up the majority of planktonic cells. Because of this, oligotrophs are crucial to oceanic nutrient cycles. However, marine oligotrophic bacteria are dwarfed by their...
    Resource Type:
    Dissertation
    Full Text:
    : ______________________________________________________ Stephen J. Giovannoni ABSTRACT Oligotrophic bacteria are adapted to low nutrient

  • Quantification of Osmolytes in the Sargasso Sea Surface Layer Water Column

    Creator:
    Muslin, Omran
    Abstract:
    Oceanic carbon cycling plays a major role in determining global atmospheric CO₂. A better understanding of dissolved organic matter and its constituents in the water column and how it affects marine carbon cycling is sought after. This study successfully measured osmolytes, low molecular zwitterionic compounds derived from amino acids, in...
    Resource Type:
    Masters Thesis
    Full Text:
    : ______________________________________________________ Stephen J. Giovannoni Oceanic carbon cycling plays a major role in determining

  • Single-Cell Genomics of Uncultivated Marine Bacteria

    Creator:
    Landry, Zachary
    Abstract:
    Historically, the difficulty of obtaining pure cultures of abundant marine microbial plankton has an obstacle to reconstructing the underlying mechanisms of biogeochemistry in the ocean. While a number of dominant marine species from the ocean surface have been cultured, the dominant microbial plankton of the dark ocean proved far more...
    Resource Type:
    Dissertation
    Full Text:
    : ______________________________________________________ Stephen Giovannoni Historically, the difficulty of obtaining pure cultures of abundant marine

  • Disturbances in a marine bacterioplankton system drive community assembly towards niche-based processes

    Creator:
    Vergin, Kevin L.
    Abstract:
    Over 100 monthly bacterioplankton DNA samples, from each of the surface and 200 m depths at the Bermuda Atlantic Time-series Study (BATS) site, were analyzed for community assembly processes. Correlation networks, filtered for potential autocorrelation artifacts, were constructed for each depth. Network characteristics for the two depths were remarkably similar...
    Resource Type:
    Masters Thesis
    Full Text:
    . Abstract approved: ______________________________________________________ Stephen J. Giovannoni

  • Metabolism of one carbon (C1) and methylated compounds in SAR11 bacteria

    Creator:
    Sun, Jing
    Abstract:
    SAR11 Alphaproteobacteria are the most abundant aerobic chemoheterotrophs in ocean surface waters. Previous studies have indicated SAR11 cells play an important role in marine carbon cycling and consume up to half of some common dissolved organic compounds, such as amino acids. During sequencing of the first SAR11 genome, genes for...
    Resource Type:
    Dissertation
    Full Text:
    in SAR11 Bacteria Abstract approved: Stephen J. Giovannoni SAR11 Alphaproteobacteria are

  • Genome-enabled investigation of the minimal growth requirements andphosphate metabolism for Pelagibacter marine bacteria

    Creator:
    Carini, Paul J.
    Abstract:
    Members of the SAR11 clade of heterotrophic α-proteobacteria are ubiquitous and abundant in the world's oceans where they are thought to play a pivotal role in the global carbon cycle. The first SAR11 bacterium cultivated in vitro, 'Candidatus Pelagibacter ubique' HTCC1062 (Ca. P. ubique), was isolated by dilution into sterile...
    Resource Type:
    Dissertation
    Full Text:
    Phosphate Metabolism for Pelagibacter Marine Bacteria Abstract approved: Stephen J. Giovannoni

  • Characterizing Growth Promoters and Inhibitors of SAR11 Pelagibacter sp. HTCC7211

    Creator:
    Lee, Connie
    Abstract:
    SAR11 is a clade of marine bacteria that are the most abundant heterotrophs in ocean surface water. They play a significant role in marine carbon cycling. Although many culturing experiments have been done on SAR11, there was no research that focused on verifying the observations about inhibition of SAR11 growth...
    Resource Type:
    Honors College Thesis
    Full Text:
    Stephen Giovannoni SAR11 is a clade of marine bacteria that are the most abundant heterotrophs

  • Culturing uncultured environmental microorganisms

    Creator:
    Connon, Stephanie A.
    Abstract:
    Research on natural environments, over the last decade, is replete with microbial diversity studies that used culture-independent approaches. The cloning and sequencing of the 16S rRNA genes has been the driving force in the expansion of awareness about the great diversity of previously undiscovered microorganisms. Well-known uncultured groups of microorganisms...
    Resource Type:
    Dissertation
    Full Text:
    Redacted for privacy ACKNOWLEDGMENTS I thank Stephen J. Giovannoni and Lewis Semprini for their

  • Characterization of novel marine oligotrophic bacteria isolated from the Pacific Ocean : description of Marinivirgula fluito gen. nov., sp. nov., Marinivirgula obesa gen. nov., sp. nov. and Litincola parvulus gen. nov., sp. nov.

    Creator:
    Shin, Eun Jung
    Abstract:
    A new high-throughput culturing (HTC) method using a low nutrient heterotrophic medium (LNHM) has led to the isolation of many novel strains of oligotrophic bacteria from marine ecosystems. Four strains belonging to a single dade, HTCC2151, HTCC218OT, HTCC2178T and HTCC2188T, were isolated from the coast of Oregon by the HTC...
    Resource Type:
    Masters Thesis
    Full Text:
    would like to express my gratitude to my major professor, Dr. Stephen Giovannoni, for the opportunity