Because of their ubiquity and resistance to spacecraft decontamination bacterial spores are considered likely potential forward contaminants on robotic missions to Mars. Thus it is important to understand their global responses to long-term exposure to space or Mars environments. As part of the PROTECT experiment spores of B. subtilis 168 were exposed to real space conditions and to simulated martian conditions for 559 days in low Earth orbit mounted on the EXPOSE-E exposure platform outside the European Columbus module on the International Space Station. Upon return spores were germinated total RNA extracted and fluorescently labeled and used to probe a custom Bacillus subtilis microarray to identify genes preferentially activated or repressed relative to ground control spores. Increased transcript levels were detected for a number of stress-related regulons responding to DNA damage (SOS response SP-beta prophage induction) protein damage (CtsR/Clp system) oxidative stress (PerR regulon) and cell envelope stress (SigV regulon). Spores exposed to space demonstrated a much broader and more severe stress response than spores exposed to simulated Mars conditions. The results are discussed in the context of planetary protection for a hypothetical journey of potential forward contaminant spores from Earth to Mars and their subsequent residence on Mars. Two-color microarrays were performed comparing germination of Space-exposed or Mars-exposed vs. ground-control (Earth) spores.

Comparing the transcriptional responses of Bacillus subtilis strains WN624 and WN1106 at 5 kPa and 101 kPa. WN1106 is a 5 kPa-evolved strain with increased fitness compared to ancestor-WN624 strain at 5 kPa. This experiment probed the difference in response when the strains are grown at 5 kPa. Two-condition experiment 5 kPa vs. 101 kPa for both strains. And two component condition of WN1106 compared to WN624 at either 5 kPa or 101 kPa. 4 pressure comparisons.

Bacillus pumilus SAFR-032 was originally isolated from the Jet Propulsion Lab Spacecraft Assembly Facility and thoroughly characterized for its enhanced resistance to UV irradiation and oxidative stress. This unusual resistance of SAFR-032 is of particular concern in the context of planetary protection and calls for development of novel disinfection techniques to prevent extraterrestrial contamination. Previously spores of SAFR-032 were exposed for 18 xe2 x80 x89months to a variety of space conditions on board the International Space Station to investigate their resistance to Mars-like conditions and space travel. Here proteomic characterization of vegetative SAFR-032 cells from space-surviving spores is presented in comparison to a ground control. Vegetative cells of the first passage were processed and subjected to quantitative proteomics using tandem mass tags. Approximately 60% of all proteins encoded by SAFR-032 were identified and 301 proteins were differentially expressed among the strains. We found that proteins predicted to be involved in carbohydrate transport/metabolism and energy production/conversion had lower abundance than those of the ground control. For three proteins we showed that the expected metabolic activities were decreased as expected with direct enzymatic assays. This was consistent with a decrease of ATP production in the space-surviving strains. The same space-surviving strains showed increased abundance of proteins related to survival growth advantage and stress response. Such alterations in the proteomes provide insights into possible molecular mechanisms of B. pumilus SAFR-032 to adapt to and resist extreme extraterrestrial environments.

Previous spaceflight experiments using Bacillus subtilis have reported altered transcriptome profiles during spaceflight compared to matching ground samples. This study tried to replicate those transcriptome changes using High Aspect Ratio Vessels (HARVs). B. subtilis spores were grown in HARVs using the same protocol and growth conditions as the BRIC-21 spaceflight mission. RNA was extracted from the HARV samples and sequenced for differential expression analysis. HARV differentially expressed genes were then compared to the genes identified as differentially expressed in the BRIC-21 mission to access the accuracy of HARVs as a model for spaceflight experiments.

The BRIC-21 mission was designed to identify the response of Bacillus subtilis to the human spaceflight environment. For this mission samples were grown in rich-medium using the Biological Research in Canister Petri Dish Fixation Units (BRIC-PDFU) spaceflight hardware. B. subtilis spores were inoculated during spaceflight grown at the ambient ISS temperature and frozen in the onboard -80 C freezer prior to returning to Earth. RNA was extracted from samples grown onboard the International Space Station (ISS) and matching Ground Controls for transcriptome analysis.

This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen Candida albicans grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 454 genes compared to synchronous ground controls which represented 8.4% of the analyzed ORFs. Spaceflight-cultured C. albicans induced genes involved in cell aggregation (similar to flocculation) which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to more normal bipolar budding patterns for ground samples in accordance with the gene expression data. Furthermore genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight including induction of ABC transporters and members of the major facilitator family downregulation of ergosterol-encoding genes and upregulation of genes involved in oxidative stress resistance. Finally downregulation of genes involved in the actin cytoskeleton was observed. Interestingly the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested as this regulator is involved in random budding cell aggregation actin cytoskeleton and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype no increased virulence in a murine intraperitoneal (i.p.) infection model was observed. This study represents an important basis for the assessment of the risk that commensal flora could play during spaceflight missions. Furthermore since the low fluid-shear environment of microgravity is relevant to physical forces encountered by pathogens during the infection process insights gained from this study could identify novel infectious disease mechanisms with downstream benefits for the general public. Cells were grown for 24 hours on the space shuttle or as ground-based controls preserved in RNALater and stored at -80C. Four samples of each flight- and ground-based controls were harvested for microarray analysis. GAP is Group Activation Pack and each GAP contains 8 FPAs. The numbers represent the # assigned to the particular GAP and the number assigned to the specific FPA (1-8) within the indicated GAP. The same hardware is used for the flight samples and the ground samples.

This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen Candida albicans grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 454 genes compared to synchronous ground controls which represented 8.4% of the analyzed ORFs. Spaceflight-cultured C. albicans induced genes involved in cell aggregation (similar to flocculation) which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to more normal bipolar budding patterns for ground samples in accordance with the gene expression data. Furthermore genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight including induction of ABC transporters and members of the major facilitator family downregulation of ergosterol-encoding genes and upregulation of genes involved in oxidative stress resistance. Finally downregulation of genes involved in the actin cytoskeleton was observed. Interestingly the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested as this regulator is involved in random budding cell aggregation actin cytoskeleton and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype no increased virulence in a murine intraperitoneal (i.p.) infection model was observed. This study represents an important basis for the assessment of the risk that commensal flora could play during spaceflight missions. Furthermore since the low fluid-shear environment of microgravity is relevant to physical forces encountered by pathogens during the infection process insights gained from this study could identify novel infectious disease mechanisms with downstream benefits for the general public. Cells were grown for 24 hours on the space shuttle or as ground-based controls preserved in RNALater and stored at -80C. Four samples of each flight- and ground-based controls were harvested for microarray analysis. GAP is Group Activation Pack and each GAP contains 8 FPAs. The numbers represent the # assigned to the particular GAP and the number assigned to the specific FPA (1-8) within the indicated GAP. The same hardware is used for the flight samples and the ground samples.

This study demonstrates simulated microgravity effects on E. coli K 12 MG1655 when grown on LB medium supplemented with glycerol. The results imply that E. coli readily reprograms itself to combat the multiple stresses imposed due to microgravity. Under these conditions it survives by upregulating oxidative stress protecting genes and simultaneously down regulating the membrane transporters and synthases to maintain cell homeostasis. In this study a clinostat that mimics microgravity conditions was used to investigate the effects of microgravity on E. coli grown in LB medium supplemented with glycerol to monitor the effects on growth and global gene expression using Affymetrix DNA microarrays.

['We report here the draft genome sequences of four strains isolated from spacecraft-associated surfaces exhibiting increased resistance to stressors such as UV radiation and exposure to H2O2. The draft genomes of strains 1P01SC, FO-92, 50v1, and 2P01AA had sizes of 5,500,894 bp, 4,699,376 bp, 3,174,402 bp, and 4,328,804 bp, respectively.']

R. rubrum S1H inoculated on solid agar rich media was sent to the ISS in October 2003 (MESSAGE-part 2 experiment). After 10 days flight R. rubrum cultures returned back to Earth. These cultures were then subjected to both transcriptomic and proteomic analysis and compared with the corresponding ground control. Whole-genome oligonucleotide microarray and high throughput proteomics which offer the possibility to survey respectively the global transcriptional and translational response of an organism were used to test the effect of space flight. Moreover in an effort to identify a specific stress response of R. rubrum to space flight ground simulation of space ionizing radiation and space gravity were performed under identical culture setup and growth conditions encountered during the actual space journey. This study is unique in combining the results from an actual space experiment with the corresponding space ionizing radiation and modeled microgravity ground simulations which lead to a more solid dissection of the different factors contribution acting in space flight conditions. Total RNA was extracted from R. rubrum S1H grown after 10 days in space flight or after 10 days in simulated ionizing radiation or simulated microgravity. Each microarray slide contained 3 technical repeats.