A5000455929- Marine and coastal ecosystems
- Phosphorus and nutrient management
- Microbial Community Ecology and Physiology
- Marine Biology and Ecology Research
- Parathyroid Disorders and Treatments
- Environmental Toxicology and Ecotoxicology
- Coral and Marine Ecosystems Studies
- Wastewater Treatment and Nitrogen Removal
- Anesthesia and Sedative Agents
- Aquatic Ecosystems and Phytoplankton Dynamics
- Chromium effects and bioremediation
- Ocean Acidification Effects and Responses
- Marine Toxins and Detection Methods
- Microbial Fuel Cells and Bioremediation
- Isotope Analysis in Ecology
- Paleontology and Stratigraphy of Fossils
- Advanced Nanomaterials in Catalysis
- Redox biology and oxidative stress
- Layered Double Hydroxides Synthesis and Applications
- Geochemistry and Geologic Mapping
- Soil and Water Nutrient Dynamics
- Coagulation, Bradykinin, Polyphosphates, and Angioedema
- Geochemistry and Elemental Analysis
- Marine Bivalve and Aquaculture Studies
- Anaerobic Digestion and Biogas Production
Scripps Institution of Oceanography
2020-2024
University of California, San Diego
2020-2024
The Ohio State University Wexner Medical Center
2024
Skidaway Institute of Oceanography
2008-2022
University of Georgia
2009-2022
Woods Hole Oceanographic Institution
2013-2019
Columbia University
1982-2015
Lamont-Doherty Earth Observatory
2015
Georgia Institute of Technology
2008-2014
Harvard University
2012-2013
The in situ or authigenic formation of calcium phosphate minerals marine sediments is a major sink for the vital nutrient phosphorus. However, because typical sediment chemistry not kinetically conducive to precipitation these minerals, mechanism behind their has remained fundamental mystery. Here, we present evidence from high-sensitivity x-ray and electrodialysis techniques describe by which abundant diatom-derived polyphosphates play critical role sediments. This can explain puzzlingly...
Superoxide and other reactive oxygen species (ROS) originate from several natural sources profoundly influence numerous elemental cycles, including carbon trace metals. In the deep ocean, permanent absence of light precludes currently known ROS sources, yet production mysteriously occurs. Here, we show that taxonomically ecologically diverse heterotrophic bacteria aquatic terrestrial environments are a vast, unrecognized, light-independent source superoxide, perhaps derived superoxide. by...
X-ray fluorescence tomography promises to map elemental distributions in unstained and unfixed biological specimens three dimensions at high resolution sensitivity, offering unparalleled insight medical, biological, environmental sciences. of has been viewed as impractical-and perhaps even impossible for routine application-due the large time required scanning significant radiation dose delivered specimen during imaging process. Here, we demonstrate submicron a whole specimen, quantifying...
Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was performed on phosphate mineral specimens including (a) twelve from the apatite group covering a range of compositional variation and crystallinity; (b) six non-apatite calcium-rich minerals; (c) 15 aluminium-rich (d) ten minerals rich in either reduced iron or manganese; (e) four oxidized (f) eight magnesium, copper, lead, zinc rare-earth elements; (g) uranium minerals. The identity all examined this study...
Abstract The reactive oxygen species superoxide (O 2 ·− ) is both beneficial and detrimental to life. Within corals, may contribute pathogen resistance but also bleaching, the loss of essential algal symbionts. Yet, role in coral health physiology not completely understood owing a lack direct situ observations. By conducting field measurements produced by corals during bleaching event, we show substantial species-specific variation external levels, which reflect balance production...
Polyphosphates are a group of phosphorus (P) containing molecules that produced by wide range microorganisms and human activities. Although polyphosphates ubiquitous in aquatic environments environmental significance, little is known about their transformation cycling. This study characterized the polyphopshate-hydrolysis mechanisms several representative phosphatase enzymes evaluated effects polyphosphate chain length, light condition, calcium (Ca2+). 31P nuclear magnetic resonance (NMR)...
Harmful bloom-forming algae include some of the most prolific microbial producers extracellular reactive oxygen species (ROS). However, taxonomic diversity ROS production, underlying physiological mechanisms and ecophysiological roles cycling are not completely characterized among phytoplankton taxa that form harmful algal blooms (HABs). This study examines production superoxide hydrogen peroxide by five marine HAB species: Chattonella marina, Heterosigma akashiwo, Karenia brevis,...
Significance Superoxide and other reactive oxygen species (ROS) are commonly regarded as harmful progenitors of biological stress death, but this view has been changing. Indeed, many phytoplankton actively generate extracellular superoxide under ideal growth conditions for reasons that mysterious. Results from study suggest production by the marine diatom Thalassiosira oceanica may promote photosynthetic health modulating oxidation state cellular NADP + /NADPH pool. The key enzyme implicated...
Abstract The coral‐algal symbiosis is the biological engine that drives one of most spectacular structures on Earth: coral reef. Here, living microhabitats are engineered using 3D bioprinting, as biomimetic model system symbiosis. Various bioinks for encapsulation photosymbiotic microalgae ( Breviolum psygmophilum ) developed and mass transfer phenomena mimicked by bioprinting tissue skeleton microscale features. At tissue–seawater interface, polyp connective successfully replicate natural...
Polyphosphate, a linear polymer of orthophosphate, is abundant in the environment and key component wastewater treatment many bioremediation processes. Despite broad relevance polyphosphate, current methods to quantify it possess significant disadvantages. Here, we describe new approach for direct quantification inorganic polyphosphate complex natural samples. The protocol relies on interaction between fluorochrome 4′,6-diamidino-2-phenylindole (DAPI) dissolved polyphosphate. With DAPI-based...
Abstract Reactive oxygen species (ROS) are key players in the health and biogeochemistry of ocean its inhabitants. The vital contribution microorganisms to marine ROS levels, particularly superoxide, has only recently come light, thus specific biological sources pathways involved production largely unknown. To better understand biogenic controls on levels tropical oligotrophic systems, we determined rates superoxide under various conditions by natural populations nitrogen‐fixing diazotroph...
Biological productivity in many ocean regions is controlled by the availability of nutrient phosphorus. In Mediterranean Sea, aerosol deposition a key source phosphorus and understanding its composition critical for determining potential bioavailability. Aerosol was investigated European North African air masses using near-edge X-ray fluorescence spectroscopy (P-NEXFS). These are main to Sea. We show that aerosols significant soluble deliver on average 3.5 times more than furthermore...
Polyphosphate (polyP) was examined within the upper water column (≤ 150 m) of Station ALOHA (22° 45′N, 158° 00′W) during two cruises conducted in May–June 2013 and September 2013. Phosphorus molar ratios particulate polyP to total phosphorus (TPP) were relatively low, similar previously reported values from temperate western North Atlantic, did not exhibit strong vertical gradients, reflecting a lack recycling relative other forms TPP with depth. Furthermore, relationships among polyP:TPP,...
The geochemical behaviors of phosphate-containing species at mineral-water interfaces are fundamental importance for controlling phosphorus mobility, fate, and bioavailability. This study investigates the sorption hydrolysis polyphosphate (a group important long-chained phosphate molecules) on aluminum oxides in presence divalent metal cations (Ca2+, Cu2+, Mg2+, Mn2+, Zn2+) pH 6-8. γ-Al2O3 with three particle sizes (5, 35, 70 nm) was used as an analogue natural to investigate size effect....
ABSTRACT Bacteria and eukaryotes produce the reactive oxygen species superoxide both within outside cell. Although is typically associated with detrimental sometimes fatal effects of oxidative stress, it has also been shown to be involved in a range essential biochemical processes, including cell signaling, growth, differentiation, defense. Light‐independent extracellular production widespread among many marine heterotrophs phytoplankton, but extent which this trait relevant microbial...
The nutritionally available pool of dissolved organic phosphorus (DOP) supports marine primary productivity in a range ocean ecosystems but remains poorly resolved. Here, the relative lability model phosphorous (P) compounds representing major P(V) bond classes DOP – phosphomonoesters (P-O-C) and phosphoanhydrides (P-O-P) was assessed diatom cultures genus Thalassiosira, as well coastal field sites western North Atlantic. In samples, maximum enzymatic hydrolysis rates revealed that...
Formation of reactive oxygen species (ROS) through partial reduction molecular is widely associated with stress within microbial and marine systems. Nevertheless, widespread observations the production ROS superoxide by healthy actively growing bacteria phytoplankton call into question role in health physiology microbes. Here, we show that produced several abundant Roseobacter clade. Superoxide levels outside cell are controlled via a tightly regulated balance decay processes response to...
The reactive oxygen species (ROS) superoxide has been implicated in both beneficial and detrimental processes coral biology, ranging from pathogenic disease resistance to bleaching. Despite the critical role of ROS health, there is a distinct lack measurements thus an incomplete understanding underpinning sources production mechanisms within systems. Here, we quantified situ extracellular concentrations at surfaces aquaria-hosted Porites astreoides during diel cycle. High (~10's nM) were...