Effect van gesimuleerde micrograviteit op het gedrag van de bacterie Cupriavidus Metallidurans CH34

In this study, the RotatingWallVessel has been used to investigate the response of the model organism Cupriavidus metallidurans CH34 to simulated microgravity and a low-shear environment. The behaviour of the strain is examined using different methodologies i.e. classical microbiology, gene expression analysis (Quantitative PCR) and protein expression analysis (2D-gelelectrophoresis). Compared to classical shake flask cultures, cells cultured in the reactor had a lower growth rate and were subject to less die-off during the stationary phase. Furthermore, the carbon source gluconate was used more efficiently in SMG than in shake flask cultures and the control RWV. Quantitative-PCR targeted a set of genes that were differentially expressed in space experiments (MESSAGE 1&2) (acxC, grpE, dpsA) and genes that are envisioned to be involved in mechanical stress (msrA, msrA1, msrA2, mscL,rseB and kefA). The three MESSAGE genes demonstrated an overexpression in simulated microgravity. GrpE and acxC were overexpressed at the maximum of the growth curve (p0,05). 2D gel electrophoresis patterns indicate clear differences in protein profiles. At this time, 8 proteins showed a differential expression profile in SMG compared to the control.