Molecule diffusion in bacteria and consequences of osmotic stress
PhD ceremony: Mr. J.T. Mika, 12.45 uur, Aula Academiegebouw, Broerstraat 5, Groningen
Dissertation: Molecule diffusion in bacteria and consequences of osmotic stress
Promotor(s): prof. B. Poolman
Faculty: Mathematics and Natural Sciences
The interior of a cell is full of different kinds of (macro)molecules, the crowding of which resembles a shopping mall just a few days before Christmas. The aim of the work of Jacek Mika was to understand how fast molecules move in such an environment. He has presented measurements on the mobility of small, medium and large molecules in the cytoplasm of E. coli. As a tool of manipulating the crowding of cells, he has exposed them to osmotic shifts. When the salt content of the external environment increases, bacterial cells, just like plant cells that have not been watered for a long time, lose water. This results in an increased crowding and a slowing down of the molecule mobility inside cells. An important outcome of the experiments presented in his thesis is that crowding and osmotic stress have more impact on macromolecules than on metabolites. In fact, severe osmotic stress ‘freezes’ proteins as they essentially become immobile. By using a special flow chamber, he has followed the fate of single E.coli cells as they experience osmotic stress. Due to their small size, bacterial cells are difficult to study with light (fluorescence) microscopy. Mika has implemented a new and exciting technique called PALM to perform microscopy of bacteria at increased resolution. This approach allows distinguishing details of structures inside cells that are as small as 10 nm, which is a great improvement as compared to the 250 nm that is the diffraction limit of conventional light microscopy.
Last modified: | 13 March 2020 12.59 a.m. |
More news
-
10 July 2025
Dutch Research Agenda funding for nanomedicine research
Prof Dr Anna Salvati, Dr Christoffer Åberg and Prof Dr Siewert-Jan Marrink have been granted a National Science Agenda (NWA) funding to further develop life-saving drugs based on nanotechnology with the NanoMedNL consortium.
-
07 July 2025
Master’s student Industrial Engineering and Management Ana Lazar wins GUF 100 Prize
At the UG Ceremony of Merits on July 4, Ana Lazar was awarded the GUF 100 Prize, making her the best student of the Faculty of Science and Engineering 2024-2025.
-
04 July 2025
University of Groningen awards various prizes during Ceremony of Merits
The UG awarded different prizes to excellent researchers and students during the Ceremony of Merits on 4 July 2025.