Dataset features


Application: Gene expression microarray analysis
Number of samples: 2
Release date: Jun 5 2010
Last update date: Nov 5 2013
Access: Public
Dataset link Rhodospirillum rubrum S1H in simulated microgravity

Experimental Protocol

At least, three independent cultures of R. rubrum S1H grown to stationary phase in Sistrom-succinate medium A containing 2 g/L Na-succinate (Sistrom, 1960) in dark aerobic conditions were resuspended in 0.85 % NaCl to a final OD680 of ca. 0.600 to constitute stock cultures. All cultures were allowed to grow for 10 days at 21 °C which are typical time frame and growth temperature of a Soyuz space flight mission (Mastroleo et al., 2009). The RWV bioreactors (Cellon, Bereldange, Luxembourg) were filled completely with ca. 58 ml of culture medium containing 1 % inoculum from the stock culture. Air bubbles were carefully removed through the sampling ports, using syringes (without needle), in order to avoid undesired shear stress. The vessels were mounted on separate RWV devices and were placed in a culture chamber, one in vertical position creating the low-shear modeled microgravity (LSMMG) environment while the control was placed in horizontal position. Gas exchange in the RWV bioreactors during growth was ensured by the gas-permeable silicone membrane present at the back of each RWV culture vessel. Bacterial growth in RWV conditions was allowed at a rotational speed of 25 rpm. After cultivation, oxygen concentration was measured by inserting the oxygen probe directly into the vessel without homogenization. After homogenization, optical density was measured at 600 nm and cells were harvested for pigment quantification as previously described (Favier-Teodorescu, 2004) and for transcriptomic and proteomic analysis. The same RWV vessels were used to cultivate R. rubrum in liquid aerobic condition using the RPM. The horizontal RWV incubation described above was also used as control for the RPM cultivation. The RPM was operated as a random walk three-dimensional clinostat (basic mode) with an angular velocity of rotation of 60 deg s-1 as previously described (Mastroleo et al., 2009). RPM - 4 technical replicates, RWV - 3 technical replicates








Natalie Leys