The Ultrastructure research department is involved in 2 microgravity projects:
Protein crystallisation in microgravity
Prof. Dr. Dominique Maes
Tel.: ++32/(0)2/629.1852
E-mail
Current team members
Mike Sleutel, Celine Vanhee, Ronnie Willaert, Lode Wyns and Dominique Maes
Keywords
Microgravity - Crystal quality - Mass transport - Growth kinetics - Nucleation - Impurities - Depletion zone
Research
Difficulties with protein crystallisation initiated attempts to conduct it in microgravity. Crystallisation of proteins in space has been a large effort (since 1982). Central to these studies on the microgravity relevant aspects of crystal growth is the recognition of the processes that could plausibly explain a different growth behavior or crystal quality in reduced gravity environments. Three hypotheses have been formulated on the mass transport related (i.e. gravity dependent) processes involved in crystal growth and that can influence the quality of the crystals:
- the depletion zone model
- the impurity depletions zone
- the instability of interfacial processes in certain growth regimes
Present microgravity research is focused on the verification of these hypotheses. Therefore, the following experiments are envisaged:
- Understanding and control of nucleation of protein crystals
- Determination of crystal quality in function of supersaturation
- Determination of the extent of depletion zones around growing crystals
- Determination of impurities, and their effect on crystal quality
- Measurement of the effect of a non-convective environment on impurity distributions and crystal quality
- Measurement the nature and extent of defects in crystals produced in different growth regimes
- Determination of the effect of these defects on the crystal quality
Project partners
Alexander A. Chernov, BAE Systems at MSFC, Huntsville, Alabama
Frank Dubois, MRC, ULB, Brussels, Belgium
Joseph Martial, Labo de Biologie Moléculaire et de Génie Génétique, Ulg, Liège, Belgium
Gregoire Nicolis, Center for Nonlinear Phenomena and Complex Systems, ULB, Brussels, Belgium
Fermín Otálora, Laboratorio de Estudios Cristalográficos, Granada, Spain
Edgard Weckert, HASYLAB at DESY, Hamburg, Germany
Sevil Weinkauf, Technische Universitaet Muenchen, Garching, Germany
Acknowledgements
This work is supported by the PRODEX program of the European Space Agency (ESA).
Cellular adhesion, biofilm formation and invasive growth of the model eukaryote Saccharomyces cerevisiae in microgravity
Dr. ir. Ronnie Willaert
Tel.: ++32/(0)2/629.1846
E-mail
Current team members
Katty Goossens, Lode Wyns and Ronnie Willaert
Keywords
Microgravity - Saccharomyces cerevisiae - Flocculation - Biofilm - Invasive growth - Systems biology - Genomics - Proteomics - Metabolic flux analysis - Structural genomics - Bioreactor
Research
The influence of microgravity on "Flo processes", cell-surface interaction on solid (biofilm formation and invasive growth) and cell-cell interaction in liquid media (flocculation), of Saccharomyces cerevisiae is studied. Microgravity has an impact on the yeast cell physiology due to a changed gravitational micro-environment and in the case of yeast cell cultivation in liquid media, also the changed shear environment in microgravity can have an effect.
The overall goal of the project is to obtain a detailed insight into the importance of gravity and shear stress on the formation of organised cell structures, such as yeast flocs, biofilms and filaments, which are of considerable interest for both fundamental science and industry as well as the medical field. Specifically, the following objectives are addressed:
- Influence of microgravity on cell-cell interaction (flocculation)
- Influence of microgravity on invasive growth of S. cerevisiae
- Influence of microgravity on the Flo processes on a systems biology level
In each case, we will compare similar experiments in normal gravity to experiments in microgravity. The results will help us to understand the mechanisms behind cellular adhesion in general, and the role of gravity in particular.
Bioreactor characterisation and fluid flow effects on cell-cell interaction will be studied using Computational Fluid Dynamics. The changed physiology will be assessed by comparing the morphology and cultivation kinetics, by using metabolic flux analysis, and transcriptome and proteome analysis. Detailed information of the Flo processes at the molecular level will be obtained by measuring the FLO transcription, atomic structure determination of the proteins (structural genomics) and functional characterisation of the carbohydrate-ligand binding. Systems biology algorithms will be developed to integrate the results from the molecular level to the whole cell level and to reveal the detailed picture of the changed physiology.
Project partners
Freddy Delvaux, Center for Malting & Brewing Science, KU Leuven, Belgium
Bart Devreese, Laboratory for Protein Biochemistry and Protein Engineering, Universiteit Gent, Ghent, Belgium
Jens Nielsen, Center for Process Biotechnology, TU Denmark, Denmark
Matthias Reuss, Institute of Biochemical Engineering, Universität Stuttgart, Germany
Paul Van Hummelen, VIB Micro Array Facility, Leuven, Belgium
Acknowledgements
This work is supported by the PRODEX program of the European Space Agency (ESA).
