A5089876219- Microbial Community Ecology and Physiology
- Marine and coastal ecosystems
- Isotope Analysis in Ecology
- Geochemistry and Elemental Analysis
- Protist diversity and phylogeny
- Genomics and Phylogenetic Studies
- Advanced Proteomics Techniques and Applications
- Marine Biology and Ecology Research
- Groundwater and Isotope Geochemistry
- Microbial Fuel Cells and Bioremediation
- Trace Elements in Health
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Algal biology and biofuel production
- Mercury impact and mitigation studies
- Wastewater Treatment and Nitrogen Removal
- Metabolomics and Mass Spectrometry Studies
- Paleontology and Stratigraphy of Fossils
- Photosynthetic Processes and Mechanisms
- Iron Metabolism and Disorders
- Diatoms and Algae Research
- Chemical Analysis and Environmental Impact
- Mass Spectrometry Techniques and Applications
- Folate and B Vitamins Research
- Cassava research and cyanide
Woods Hole Oceanographic Institution
2016-2025
University of Hawaiʻi at Mānoa
2022
Ocean Institute
2022
Woodwell Climate Research Center
2018
University of Rhode Island
2008
United States Geological Survey
2007
University of Massachusetts Dartmouth
2005
We present a novel method for nitrogen and oxygen natural isotopic abundance analysis of nitrate nitrite seawater freshwater at environmental concentrations. The involves the reduction to using spongy cadmium with further nitrous oxide sodium azide in an acetic acid buffer. For separate analysis, step is simply bypassed. Nitrous purged from water sample trapped cryogenically automated system subsequent release into gas chromatography column. isolated then analyzed on continuous flow isotope...
Archaea may account for the majority of marine nitrous oxide emissions to atmosphere.
The bacterial conversion of aqueous nitrate (NO3−) to nitrous oxide (N2O) for isotopic analysis has found widespread use since its introduction (Sigman, D. M.; Casciotti, K. L.; Andreani, Galanter, Böhlke, J. Anal. Chem.2001, 73, 4145−4153; Sigman, Galanter Hastings, K.; Hilkert, A. Chem.2002, 74, 4905−4912). strain Pseudomonas aureofaciens (ATTC no. 13985) was shown convert NO3− N2O while retaining both N and O signatures, automation the greatly increased throughput method (Casciotti,...
Significance Thaumarchaeota are among the most abundant microbial cells in ocean, but to date, complete genome sequences for marine lacking. Here, we report 1.23-Mbp of pelagic ammonia-oxidizing thaumarchaeon “ Candidatus Nitrosopelagicus brevis” str. CN25. We present first proteomic data, our knowledge, from this phylum, which show a high proportion proteins translated oligotrophic conditions. Metagenomic fragment recruitment using data open ocean indicate ubiquitous presence Ca. N....
Protein markers of cyanobacterial stress Nutrients including iron, nitrogen, and phosphorus limit primary productivity in the oceans. Determining how abundant cyanobacteria such as Prochlorococcus adapt to nutrient across marine settings requires accurate molecular assays. Saito et al. developed a proteomic metaproteomic approach capable targeting specific metabolic biomarkers from mixed communities seawater (see Perspective by Moore). proteins are indicative major limiting wide transect...
Significance Iron limits marine production across one third of the surface ocean. The chemical form iron in these regions is unknown, but it well established that molecular speciation affects microbial competition for uptake. Here we show abundance and identity siderophores, strong iron-binding compounds secreted by microbes to enhance uptake, changes iron-replete iron-deficient South Pacific Ocean. In low-iron regions, amphiphilic siderophores are particularly abundant, suggesting a...
We present 28 multiple sulfur isotope measurements of seawater sulfate (δ34SSO4 and Δ33SSO4) from the modern ocean over a range water depths sites along eastern margin Pacific Ocean. The average measured δ34SSO4 is 21.24‰ (±0.88‰,2σ) with calculated Δ33SSO4 +0.050‰ (±0.014‰,2σ). With these values, we use box-model to place constraints on gross fraction pyrite burial in sediments. This model presents an improvement previous estimates global flux because it does not rely assumed value...
Nitrite is a central intermediate in the nitrogen cycle and can persist significant concentrations ocean waters, sediment pore terrestrial groundwaters. To fully interpret effect of microbial processes on nitrate (NO3-), nitrite (NO2-), nitrous oxide (N2O) cycling these systems, pool must be accessible to isotopic analysis. Furthermore, because interferes with most methods analysis, accurate analysis essential for correct measurement isotopes sample that contains nitrite. In this study,...
We examined the oxygen isotopic systematics for ammonia oxidation, first step in regeneration of nitrate from ammonium. In particular, fractionation and exchange with water were evaluated their roles determining δ 18 O nitrite produced by four species ammonia‐oxidizing bacteria (AOB). Microbially catalyzed between was less than 25% at low cell densities (10 6 cells mL −1 ) ammonium concentrations (less 50 µmol L ). The amount relatively constant a given oxidizer but varied 1% among tested....
Abstract Nitrogen fixation rates of the globally distributed, biogeochemically important marine cyanobacterium Trichodesmium increase under high carbon dioxide (CO 2 ) levels in short-term studies due to physiological plasticity. However, its long-term adaptive responses ongoing anthropogenic CO increases are unknown. Here we show that experimental evolution extended selection at projected future elevated results irreversible, large nitrogen and growth rates, even after being moved back...
The δ 18 O value of nitrate produced during nitrification (δ NO3,nit ) was measured in experiments designed to mimic oceanic conditions, involving cocultures ammonia‐oxidizing bacteria or archaea and nitrite‐oxidizing bacteria, as well natural marine assemblages. estimates ranged from −1.5‰ ± 0.1‰ +1.3‰ 1.4‰ at values water (H 2 O) dissolved oxygen (O 0‰ 24.2‰ vs. Vienna Standard Mean Ocean Water, respectively. Additions O‐enriched H allowed us evaluate the effects (O) isotope fractionation...
In this study, we develop a mechanistic understanding of how temperature affects growth and photosynthesis in 10 geographically physiologically diverse strains Synechococcus spp. We found that are able to regulate photochemistry over range temperatures by using state transitions altering the abundance photosynthetic proteins. These strategies minimize photosystem II (PSII) photodamage keeping electron transport chain (ETC), hence PSII reaction centers, more oxidized. At approach optimal each...
The genus Nitrospira is the most widespread group of nitrite-oxidizing bacteria and thrives in diverse natural engineered ecosystems. marina Nb-295T was isolated from ocean over 30 years ago; however, its genome has not yet been analyzed. Here, we investigated metabolic potential N. based on complete sequence performed physiological experiments to test genome-derived hypotheses. Our data confirm that benefits additions undefined organic carbon substrates, adaptations resist oxidative,...
Until recently, the process of denitrification (conversion nitrate or nitrite to gaseous products) was thought be performed exclusively by prokaryotes and fungi. The finding that foraminifera perform complete could impact our understanding removal in sediments as well eukaryotic respiration, especially if it is widespread. However, details this subcellular location these reactions remain uncertain. For example, prokaryotic endobionts, rather than foraminifer proper, denitrification, has been...
Three proteins related to vitamin B 12 metabolism in diatoms were quantified via selected reaction monitoring mass spectrometry: ‐dependent and ‐independent methionine synthase (MetH, MetE) a acquisition protein (CBA1). ‐mediated interreplacement of MetE MetH metalloenzymes was observed Phaeodactylum tricornutum where abundance highest (0.06 fmol µg −1 protein) under high increased 3.25 low availability. Maximal 60‐fold greater than MetH, consistent with the expected ∼ 50–100‐fold larger...
Significance Conventional knowledge suggests that coastal phytoplankton are less able to adapt Fe limitation than open ocean species. Here we show in contrast the established paradigm, Synechococcus from New England shelf is capable of dynamic, multitiered adaptation allows it thrive over a broad range concentrations by partitioning among different uptake and storage proteins. This protein-based response beneficial high nitrogen (N) waters with low variable Fe:N ratios. An oceanic Atlantic...
Pathogenic<italic>Staphylococcus aureus</italic>respond to copper stress by altering central carbon metabolism in response a specific inhibition of the glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase.