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Organic mass in the surface ocean is made up of 50% polysaccharides which are consumed by bacteria. In this video, GRETA GILJAN examines how bacterial consumption of polysaccharides takes place as well as its carbon impact. Giljan employs fluorescently labeled polysaccharides (FLA-PS) to show how different bacteria use variant methods to take up polysaccharides at particular times of year. The research further demonstrates that of the two mechanisms explored, extra cellular hydrolysis has a very different carbon impact to so-called “selfish uptake”. One of the key aims of the work going forward will be to explore whether bacteria can switch between these different mechanisms in polysaccharide uptake.


Having completed her PhD research in July 2020 on a thesis entitled “Flow Sorting of Marine Bacteria for Targeted Metabolic Studies”, Greta Giljan is currently a scientific associate at the Max Planck Institute for Marine Microbiology in Bremen. Her research focuses on the metabolic activity and potential of select marine bacteria. Further research interests include flow cytometry and the polysaccharide uptake of heterotrophic bacteria.


Max Planck Institute for Marine Microbiology

At the Max Planck Institute for Marine Microbiology (MPIMM), we are investigating microorganisms in the sea and other waters. What role do they play, what are their characteristics and how great is their biodiversity? What is the contribution of microorganisms to the global cycles of carbon, nitrogen, sulfur and iron? What does this mean for our environment and our climate? These and many other questions will be answered by researchers from around the world, engineers, technicians and numerous others at the MPIMM. Their fields of expertise range from microbiology to microsensors, geochemistry to genome analysis and molecular ecology to modelling. The MPIMM was founded in 1992 and is part of the Max Planck Society (MPG). Since 2002, the MPIMM has been running the International Max Planck Research School of Marine Microbiology ( MarMic ), a program for highly qualified master students and graduates of our institute and the Bremen Research Alliance partner Bremen University, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research ( AWI ) and Jacobs University.
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Original publication

Visualizing and quantifying mechanism of polysaccharide utilizing bacteria: Methodological guidelines, and an example from the North Sea

Giljan Greta
Published in 2020

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