Opportunities for training, graduate programs, postdoctoral fellowships, jobs, and grants are posted here.
Algae drive the global carbon cycle and are the basis of extensive freshwater and oceanic food webs. One algal group, the diatoms, perform ~20% of global primary production – more than all the rainforests combined. At the heart of diatom carbon-fixation is the pyrenoid – a biomolecular condensate of the CO2-fixing enzyme Rubisco. The pyrenoid turbocharges photosynthesis by concentrating and releasing CO2 in specialized thylakoid membranes that traverse the Rubisco dense matrix of the pyrenoid. Despite its global fundamental importance, very little is known about the diatom pyrenoid. Broader, understanding algal carbon fixation and our ability to engineer it has the potential to improve photosynthesis to enhance crop yields and boost biological based carbon capture methods. In this PhD project the selected student will investigate the specialized thylakoid membranes that traverse the diatom pyrenoid. They will explore the formation, protein composition and function of these membranes. They will investigate how Rubisco condensates are attached to these membranes and how large protein assemblies influence membrane properties. To do this they will use a recently established diatom molecular toolkit to localize candidate proteins to understand their spatial distribution within the pyrenoid. In parallel, CRISPR/Cas will be used to knock out target genes to understand functional and structural importance. Biochemical approaches combined with CryoEM will be used to link protein structure to function and cryoET will be applied to understand in-situ structural changes. All relevant training will be provided. Photosynthetic algae underpin life in our oceans. Diatoms, characterised by their intricate silica cell walls, represent one of the most abundant algal groups in marine and freshwater ecosystems. Their unique biology means that they also have an important role in biotechnological applications, including biomineralisation and the production of biofuels. Marine and freshwater environments experience significant fluctuations in temperature that diatoms must be able to tolerate in order to survive. The frequency and extent of these temperature fluctuations is predicted to increase dramatically in the next century, which is likely to have a major impact on the physiology of diatoms. However, we currently know very little about the cellular mechanisms of thermal tolerance in diatoms. The project will examine thermal tolerance in diatoms to better understand their physiological responses to different temperature regimes and the signalling processes that allow them to rapidly respond to temperature fluctuations In plants and algae, one of the major consequences of elevated temperatures is the production of reactive oxygen species (ROS) in the chloroplast due to thermal sensitivity of the photosynthetic machinery. High concentrations of ROS are likely to be extremely damaging to the cell and may lead to cell death. However, lower concentrations of ROS may play an important signalling role, allowing the cell to rapidly respond to thermal stress. In this project, we will use the model diatom Phaeodactylum tricornutum to examine ROS production under different temperature regimes. We have generated a range of strains expressing genetically encoded fluorescent reporters for ROS that allow monitoring of stress responses in real time in single cells. Photonic crystals are complex optical nanomaterials that function through the interference with light. Photonic crystals exhibit remarkable optical properties, finding applications in diverse modern technologies like telecommunications, photovoltaics, and quantum computing. Interestingly, photonic crystals also exist in nature, in the silicon dioxide shells surrounding diatoms. Their photonic crystals are exceptionally well-defined, confining photonic properties to narrow spectral ranges. While reproducibility is advantageous for photonics applications, it also poses limitations for industrial use, where more diverse photonic properties are required on demand. To address this bottleneck, we aim to unravel the molecular mechanisms governing the growth of diatom photonic crystals. This approach bases on studying the processes during meiotic cell reproduction stages in diatoms. At this point, the glass shells temporarily disappear, only to be reassembled once the reproductive cycle concludes. We anticipate that crucial genes, responsible for synthesizing natural photonic crystals, are activated during these stages. Additionally, we plan to monitor the reinstallation of diatom photonic crystals with advanced microscopic imaging techniques, including confocal microscopy, Scanning and Transmission Electron Microscopy (SEM and TEM). Proxy component: The diatom-based oxygen isotope (δ18O(diatom)) proxy for Antarctic glacial discharge will be anlysed on LIG and recent sediments from the iceberg alley in the deep Southern Ocean. δ18O(diatom) and other proxies (eg. ice-rafted debris, diatom assemblages) will be employed to resolve Antarctic ice sheet discharge events. Modelling component: There are multiple benefits that arise from including water tracers in climate models, including (1) the ability to assess relationships between isotopic concentrations and ocean-climate variables, ensuing the most accurate interpretation of stable water isotopic measurement from sediment cores to provide important long-term records of past changes, and (2) representation of water tracers and isotopes within UKESM2 (UK Earth System Model) allows us to gain a better understanding of crucial hydrological processes within the model and better predict how the earth system will respond to Antarctic meltwater events under future climate change. The Central Collection of Algal Cultures (CCAC) is one of the largest living culture collections of microalgae worldwide. Embedded in the strategic research area “Water Research” at UDE, the CCAC team maintains this resource and serves research and teaching activities at UDE and beyond by delivering algal cultures, engaging in collaborations, and providing consultation. The algal collection actively participates in research projects. The position needs German and English proficiency. / Die Central Collection of Algal Cultures (CCAC) ist eine der größten Lebendsammlungen von Mikroalgenkulturen weltweit. Eingebettet in den Profilschwerpunkt Wasserforschung der UDE, hält das CCAC-Team diese Ressource aufrecht, und bedient Forschungs- und Lehraktivitäten an der UDE sowie außerhalb durch die Lieferung von Algenkulturen, Kooperationen und Beratung. Die Algensammlung beteiligt sich außerdem aktiv an Forschungsprojekten. Bioelectricity underpins highly sophisticated signalling across all domains of life. Recently, electrical excitability (rapid changes in membrane potential) has been discovered in single-celled, red-lineage phytoplankton. These microscopic marine algae produce half of Earth’s atmospheric oxygen and are the trophic entry point for all life in the ocean, with great influence on ocean biogeochemistry. Single-celled algae may be the most abundant excitable cells in the ocean, yet our understanding of the nature and consequences of their electrical behaviour is sparse. In animals, excitability is responsible for transmitting information throughout the body, coordinating movement, responses to environment, and regulating cellular processes. Why then, is this ability present in marine algae? Diatoms are a significant phytoplankton group. They fuel food webs and are major players in the global carbon cycle. Diatoms are particularly important in nutrient rich coastal waters and shelf seas. Despite our dependence on these critical components of the Earth system there is a limited understanding of marine diatom health and disease. A range of protists and some fungal parasites infect diatoms. Bacteria are also associated with diatoms as part of their microbiomes. At present we have a limited understanding of the role of bacterial microbiomes on parasite infection of marine diatoms. Given the importance of marine diatoms, it is critical that we now understand the relationship between marine diatoms, their bacterial microbiomes and parasite infection on their biomass and diversity, and establish the impacts on diatom ecosystem function, particularly their critical role in the marine carbon cycle. Post-Doc Offer – DNA metabarcoding: diatom biomonitoringFurther Information:
Further Information: