A5041273148- Marine and coastal ecosystems
- Microbial Community Ecology and Physiology
- Hydrocarbon exploration and reservoir analysis
- Isotope Analysis in Ecology
- Aquatic Ecosystems and Phytoplankton Dynamics
- Metabolomics and Mass Spectrometry Studies
- Genomics and Phylogenetic Studies
- Species Distribution and Climate Change
- Porphyrin Metabolism and Disorders
- Biocrusts and Microbial Ecology
- Methane Hydrates and Related Phenomena
- Marine Biology and Ecology Research
- Analytical Chemistry and Chromatography
- Ocean Acidification Effects and Responses
- Soil and Water Nutrient Dynamics
- Algal biology and biofuel production
- Constructed Wetlands for Wastewater Treatment
- Analytical Chemistry and Sensors
- Protist diversity and phylogeny
- Fish Ecology and Management Studies
- Cassava research and cyanide
- Geochemistry and Geologic Mapping
- Wastewater Treatment and Nitrogen Removal
- Physiological and biochemical adaptations
- Marine Bivalve and Aquaculture Studies
University of Michigan
2020-2024
Harvard University
2018-2022
Planetary Science Institute
2018-2022
Harvard University Press
2021
Scripps Institution of Oceanography
2013-2018
University of California, San Diego
2013-2018
The dynamics of the particulate organic carbon (POC) pool in ocean are central to marine cycle. POC is link between surface primary production, deep ocean, and sediments. rate at which degraded dark can impact atmospheric CO2 concentration. Therefore, a focus geochemistry studies improve our understanding distribution, composition, cycling. last few decades have seen improvements analytical techniques that greatly expanded what we measure, both terms compound structural diversity isotopic...
Abstract Western Lake Erie experiences an annual, toxic cyanobacterial harmful algal bloom (cyanoHAB), primarily caused by excess anthropogenic inputs of nitrogen (N) and phosphorous (P) . Because the non‐N fixing cyanobacteria species Microcystis dominates these blooms, N availability is hypothesized to play a central role in cyanoHAB progression, as well production N‐rich toxin microcystin. Many previous studies focused on nitrate because it most abundant substrate during initiation....
Abstract Hopanoid lipids, bacteriohopanols and bacteriohopanepolyols, are membrane components exclusive to bacteria. Together with their diagenetic derivatives, they commonly used as biomarkers for specific bacterial groups or biogeochemical processes in the geologic record. However, sources of hopanoids marine freshwater environments remain inadequately constrained. Recent marker gene studies suggest a widespread potential hopanoid biosynthesis bacterioplankton, including nitrifying (i.e.,...
ABSTRACT Hopanoids are pentacyclic triterpenoid lipids produced by many prokaryotes as cell membrane components. The structural variations of composite hopanoids, or bacteriohopanepolyols (BHPs), various bacterial genera make them potentially useful molecular biomarkers communities and metabolic processes in both modern ancient environments. Building on previous work suggesting that organisms low-oxygen environments important contributors to BHP production the marine water column there may...
Significance Hopanoids are bacterial membrane lipids that abundant in the geologic record. methylated at C-2 position (2-methylhopanoids) particularly during Mesozoic episodes of ocean anoxia, yet sources and factors contribute to accumulation these biomarkers remain poorly understood. Here, we report 2-methylhopanoid production Nitrobacter , a ubiquitous group nitrite-oxidizing bacteria favored under nutrient-rich growth environments, demonstrate biosynthesis depends on cobalamin (vitamin B...
Interactions between bacteria and phytoplankton can influence primary production, community composition, algal bloom development. However, these interactions are poorly described for many consortia, particularly freshwater bloom-forming cyanobacteria. Here, we assessed the gene content expression of two uncultivated Acidobacteria from Lake Erie Microcystis blooms. These organisms were targeted because they previously identified as important catalase producers in blooms, suggesting that...
Abstract Nutrient-induced blooms of the globally abundant freshwater toxic cyanobacterium Microcystis cause worldwide public and ecosystem health concerns. The response growth toxin production to new recycled nitrogen (N) inputs impact heterotrophic bacteria in phycosphere on these processes are not well understood. Here, using microbiome transplant experiments, cyanotoxin analysis, nanometer-scale stable isotope probing measure N incorporation exchange at single cell resolution, we...
Elevated organic matter (OM) export flux promotes marine anoxia, thus increasing carbon sequestration efficiency and decreasing atmospheric dioxide levels. However, the mechanisms that trigger sustain anoxic events—particularly those associated with nutrient-poor, oligotrophic surface waters—remain poorly constrained. Mediterranean Sea sapropels are well-preserved sediments deposited during episodic events throughout Plio-Pleistocene; as such, they may provide unique insight into...
Hopanoids, including the extended side chain-containing bacteriohopanepolyols, are bacterial lipids found abundantly in geological record and across Earth's surface environments. However, physiological roles of this biomarker remain uncertain, limiting interpretation their presence current past Recent work investigating diversity distribution hopanoid producers marine environment implicated low-oxygen regions as important loci production, data from oxygen minimum zones suggested that...
Abstract Nutrient-induced blooms of the globally abundant freshwater toxic cyanobacterium Microcystis are cause worldwide public and ecosystem health concerns. The response growth toxin production to new recycled nitrogen (N) inputs, impact heterotrophic bacteria in phycosphere on these processes not well understood. Here, using microbiome transplant experiments, cyanotoxin analysis, stable isotope tracing measure N incorporation exchange at single cell resolution, we monitored growth,...