Verena Schrameyer

Verena Schrameyer
University of Copenhagen · Marine Biology

PhD

About

29
Publications
4,972
Reads
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409
Citations
Additional affiliations
March 2009 - November 2013
University of Technology Sydney
Position
  • PhD Student
February 2006 - October 2007
The University of Queensland
Position
  • Occupational Trainee
Description
  • With the project I undertook at UQ, I finalised my german Master degree in Marine Science. In specific I worked on coral skeletal luminescence banding patterns to assess the impact of extreme rainfall events upon coral reefs.

Publications

Publications (29)
Article
Full-text available
Denitrification supports anoxic growth of Pseudomonas aeruginosa in infections. Moreover, denitrification may provide oxygen (O2) resulting from dismutation of the denitrification intermediate nitric oxide (NO) as seen in Methylomirabilis oxyfera. To examine the prevalence of NO dismutation we studied O2 release by P. aeruginosa in airtight vials....
Article
Full-text available
Iodide ions (I-) are an essential dietary mineral, and crucial for mental and physical development, fertility and thyroid function. I- is also a high affinity substrate for the heme enzyme myeloperoxidase (MPO), which is involved in bacterial cell killing during the immune response, and also host tissue damage during inflammation. In the presence o...
Article
Full-text available
Plastic pollution is a global threat to marine ecosystems. Plastic litter can leach a variety of substances into marine environments; however, virtually nothing is known regarding how this affects photosynthetic bacteria at the base of the marine food web. To address this, we investigated the effect of plastic leachate exposure on marine Prochloroc...
Article
There is a strong need for techniques that can quantify the important reactive oxygen species hydrogen peroxide (H2O2) in complex media and in vivo. We combined chemiluminescence-based H2O2 measurements on a commercially available flow injection analysis (FIA) system with sampling of the analyte using microdialysis probes (MDPs), typically used for...
Poster
Full-text available
Exact determination of hydrogen peroxide (H2O2) concentrations in environmental samples as well as in the human body is one of the key challenges for understanding its dual role in biochemical processes as e.g. signaling agent, oxidative stress marker or cytotoxin. Thus, new or optimized sensors system allowing real time, selective, minimally invas...
Poster
Full-text available
Pseudomonas aeruginosa expresses a flexible metabolism including utilisation of nitrogen oxides (NOx) as electron acceptors for anaerobic respiration by denitrification contributing to chronic infection. Here, nitric oxide reductase mutant P. aeruginosa grown in airtight vials displayed rapid depletion of O2 from normoxic media (∼200 µM O2) with su...
Article
Full-text available
HIGHLIGHTS: Sedimentation of fine sediment particles onto seagrass leaves severely hampers the plants' performance in both light and darkness, due to inadequate internal plant aeration and intrusion of phytotoxic H2S. Anthropogenic activities leading to sediment re-suspension can have adverse effects on adjacent seagrass meadows, owing to reduced...
Article
Full-text available
Despite extensive work on the genetic diversity of reef invertebrate-dinoflagellate symbioses on the Great Barrier Reef (Australia), there are large gaps in our knowledge from its northern regions. Therefore, a broad survey was done comparing the community of inshore, mid-shelf and outer reefs at the latitude of Lizard Island. Symbiodinium (Freuden...
Article
Full-text available
The in hospite Symbiodinium symbiont of corals on shallow reefs relies on photoprotection and photorepair during periods of exposure to short-term high light and/or temperature stress. A coral’s susceptibility to bleaching is species specific and determined not only by Symbiodinium type, size and physiology, but also by coral host features. Here, p...
Article
Full-text available
There is an urgent need to develop and implement rapid assessments of coral health to allow effective adaptive management in response to coastal development and global change. There is now increasing evidence that activation of caspase-dependent apoptosis plays a key role during coral bleaching and subsequent mortality. In this study, a “clinical”...
Article
Full-text available
The light dependency of respiratory activity of two scleractinian corals was examined using O2 microsensors and CO2 exchange measurements. Light respiration increased strongly but asymptotically with elevated irradiance in both species. Light respiration in Pocillopora damicornis was higher than in Pavona decussata under low irradiance, indicating...
Article
Despite extensive work on the genetic diversity of reef invertebrate-dinoflagellate symbioses on the Great Barrier Reef (Australia), large information gaps exist from northern and inshore regions. Therefore, a broad survey was done comparing the community of inshore, mid-shelf and outer reefs at the latitude of Lizard Island. Symbiodinium (Freudent...
Article
Full-text available
This study examined the capacity for photoprotection and repair of photo-inactivated photosystem II in the same Symbiodinium clade associated with two coexisting coral species during high-light stress in order to test for the modulation of the symbiont’s photobiological response by the coral host. After 4 days exposure to in situ irradiance, symbio...
Data
Interactive comment on "Breakdown of the coral-algae symbiosis: towards formalising a linkage between warm-water bleaching thresholds and the growth rate of the intracellular zooxanthellae" by S. A. Wooldridge This paper provides a well-presented model for explaining warm-water bleaching in hard corals. It also attempts to use this model to explain...
Article
Full-text available
The cyanobacterium Acaryochloris marina is the only known phototroph harboring chlorophyll (Chl) d. It is easy to cultivate it in a planktonic growth mode, and A. marina cultures have been subject to detailed biochemical and biophysical characterization. In natural situations, A. marina is mainly found associated with surfaces, but this growth mode...
Article
Full-text available
Coral core records, combined with measurements of coral community structure, were used to assess the long-term impact of multiple environmental stressors on reef assemblages along an environmental gradient. Multiple proxies (luminescent lines, Ba/Ca, δ15N) that reflect different environmental conditions (freshwater discharge, sediment delivery to t...

Network

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Projects

Projects (2)
Project
In my new project at the University of Copenhagen, I will be working as a Marie Curie Postdoctoral Research Fellow and study underlying physiological mechanisms of a coral bleaching response. Global climate changes affect coral reefs worldwide and these valuable marine biodiversity hotspots are increasingly experiencing a symbiotic dysfunction known as coral bleaching, where the global bleaching events in 2016 were the most significant to date. One of the main focusses of this project is to understand the underlying physiological mechanisms inducing the bleaching responses. It is known that cellular oxidative stress and reactive species such as nitric oxide (NO) and hydrogen peroxide (H2O2) are involved, but the sources and sinks of these compounds, their interplay and spatio-temporal dynamics have not been investigated in corals, partly due to lack of suitable experimental tools. The DENOCS projects will apply a suite of novel quantitative assessment techniques to investigate the dynamics and impact sites of NO and H2O2 in intact corals, coral tissue culture, and isolated photosymbionts when subjected to experimental treatments mimicking global change-induced environmental stress scenarios.
Archived project
Picocyanobacteria such as Prochlorococcus are the most abundant and yet the smallest phototrophs in the oceans. Prochlorococcus marinus ecotypes, are ubiquitous and major contributors to primary productivity and photosynthetic biomass of the oceans worldwide. Detailed analysis of the effects of anthropogenic pollutants upon their photophysiology is central to the research of this project, where different types of plastic leachate, relevant to marine anthropogenic pollutants, are being used for testing. A suite of measuring techniques is being combined to focus on the primary productivity, photosynthetic efficiency, as well as growth parameters considering cell counts as well as pigmentation.