A5040326598- Marine and coastal ecosystems
- Microbial Community Ecology and Physiology
- Marine Biology and Ecology Research
- Genomics and Phylogenetic Studies
- HIV Research and Treatment
- HIV/AIDS Research and Interventions
- Bacteriophages and microbial interactions
- Vibrio bacteria research studies
- Oceanographic and Atmospheric Processes
- Evolution and Genetic Dynamics
- Identification and Quantification in Food
- Hydrocarbon exploration and reservoir analysis
- Protist diversity and phylogeny
- Bacterial biofilms and quorum sensing
- Immune Cell Function and Interaction
- HIV-related health complications and treatments
- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Micro and Nano Robotics
- Evolutionary Game Theory and Cooperation
- Diffusion and Search Dynamics
University of North Carolina at Chapel Hill
2019-2024
Macrophages have long been considered to contribute HIV infection of the CNS; however, a recent study has contradicted this early work and suggests that myeloid cells are not an in vivo source virus production. Here, we addressed role macrophages by first analyzing monocytes isolated from viremic patients undergoing antiretroviral treatment. We were unable find viral DNA or outgrowth peripheral blood. To determine whether tissue productively infected, used 3 different but complementary...
Abstract Microbial community dynamics on sinking particles control the amount of carbon that reaches deep ocean and length time is stored, with potentially profound impacts Earth’s climate. A mechanistic understanding controls particle distributions has been hindered by limited depth- time-resolved sampling methods cannot distinguish individual particles. Here, we analyze microbial communities nearly 400 in conjunction more conventional composite samples to determine how colonization...
The NASA EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) program was established to better quantify pathways of biological carbon pump order gain a more comprehensive understanding global export efficiency. summer 2018 field campaign vicinity Station Papa (Station P; 50°N, 145°W) Northeast Pacific yielded evidence low phytoplankton biomass and primary productivity dominated by small cells (<5 µm) that are reliant on recycled nutrients. Using combined 13C/15N stable isotope...
Bacteria employ antagonistic strategies to eliminate competitors of an ecological niche. Contact-dependent mechanisms, such as the type VI secretion system (T6SS), are prevalent in host-associated bacteria, yet we know relatively little about how T6SS+ strains make contact with highly viscous environments, host mucus. To better understand cells respond and one another performed a genome-wide transposon mutant screen T6SS-wielding beneficial bacterial symbiont,
The marine bacterium Vibrio fischeri efficiently colonizes its symbiotic squid host, Euprymna scolopes, by producing a transient biofilm dependent on the symbiosis polysaccharide (SYP). In vitro, however, wild-type strain ES114 fails to form SYP-dependent biofilms. Instead, genetically engineered strains, such as those lacking negative regulator BinK, have been developed study this phenomenon. Historically, V. has grown using LBS, complex medium containing tryptone and yeast extract;...
Abstract The type VI secretion system (T6SS) is an interbacterial weapon composed of thousands protein subunits and predicted to require significant cellular energy deploy, yet a fitness cost from T6SS use rarely observed. Here, we identify host-like conditions where the incurs using beneficial symbiont, Vibrio fischeri , which uses its eliminate competitors in natural squid host. We hypothesized that for could be dependent on energetic state used theoretical ATP estimates predict when...
Abstract The second field campaign of the NASA EXport Processes in Ocean from RemoTe Sensing (EXPORTS) program was conducted late spring 2021 within vicinity Porcupine Abyssal Plain (49.0°N, 16.5°W) North Atlantic Ocean. Observations EXPORTS support previous characterizations this system as highly productive and organic matter rich, with majority primary production occurring large cells (≥ 5 µm) such diatoms that are primarily utilizing nitrate. Rates total euphotic zone depth-integrated net...
Abstract The North Atlantic is a region of enhanced biogeochemical and climatological importance for the global ocean as it site one largest seasonal phytoplankton blooms on planet. However, there lack understanding how size influences bloom dynamics associated nutrient utilization rates, particularly during decline phase when export to deep especially pronounced. Here, we evaluate trends in size‐fractionated carbon, nitrogen, silicic acid uptake rates conjunction with environmental...
The Roseobacter clade is a group of alphaproteobacteria that have diverse metabolic and regulatory capabilities. They are abundant in marine environments substantial role ecology biogeochemistry. However, interactions between roseobacters other bacterioplankton not been extensively explored. In this study, we identify killing mechanism the model roseobacter Ruegeria pomeroyi DSS-3 by coculturing it with phylogenetically bacteria. diffusible occurs when cells grown both on surfaces suspension...
Microbial respiration is a critical component of the marine carbon cycle, determining proportion fixed that subject to remineralization as opposed being available for export ocean depths. Despite its importance, methodological constraints have led an inadequate understanding this process, especially in low-activity oligotrophic and mesopelagic regions. Here, we quantify rates low 0.2 µ mol O 2 L -1 d contrasting productivity provinces using oxygen optode sensors identify size-fractionated...
ABSTRACT Microbial respiration plays a pivotal role in the marine carbon cycle, influencing fraction of fixed that undergoes remineralization versus export to depth. Despite its importance, methodological constraints have led an inadequate understanding this process, especially low-activity oligotrophic and mesopelagic regions. Here, we quantify rates as low 0.2 µ mol O2 L -1 d contrasting ocean productivity provinces using optical oxygen sensors identify size-fractionated trends. At North...
Synechococcus are the most abundant cyanobacteria in high latitude regions and responsible for an estimated 17% of annual marine net primary productivity. Despite their biogeochemical importance, populations have been unevenly sampled across ocean, with studies focused on low-latitude strains. In particular, near absence genomes from high-latitude, High Nutrient Low Chlorophyll (HNLC) leaves a gap our knowledge picocyanobacterial adaptations to iron limitation influence carbon, nitrogen,...
Abstract The roseobacter clade is a group of α-proteobacteria that have diverse metabolic and regulatory capabilities. They are abundant in marine environments substantial role ecology biogeochemistry. However, interactions between roseobacters other bacterioplankton not been extensively explored. In this study, we identify killing mechanism the model Roseobacter Ruegeria pomeroyi DSS-3 by competing it against phylogenetically bacteria. involves an unidentified antimicrobial compound...
Abstract Synechococcus are the most abundant cyanobacteria in high latitude regions and responsible for an estimated 17% of annual marine primary productivity. Despite their biogeochemical importance, populations have been unevenly sampled across ocean, with studies focused on low-latitude strains. In particular, near absence genomes from high-latitude, High Nutrient Low Chlorophyll (HNLC) leaves a gap our knowledge picocyanobacterial adaptation to iron limitation influence carbon, nitrogen,...