Safe geological disposal of radioactive waste requires a thorough understanding of geochemical conditions in the host formation. Boom Clay is a potential candidate in Belgium, where active methanogenesis has been detected in its deep subsurface, influencing the local geochemistry. However, the pathways driving this process and the characteristics of the methanogenic archaea involved remain unclear.
View Article and Find Full Text PDFApproaches to DNA extraction play a crucial role in determining the variability of results obtained through 16S rRNA amplicon sequencing. Particularly, clay-rich samples can impede the efficiency of various standard cultivation-independent techniques. We conducted an inter-laboratory comparison study to thoroughly assess the efficacy of two published DNA extraction methods (kit-based and phenol-chloroform-based) specifically designed for bentonite samples.
View Article and Find Full Text PDFRegenerative life support systems for space crews recycle waste into water, food, and oxygen using different organisms. The European Space Agency's MELiSSA program uses the cyanobacterium Limnospira indica PCC8005 for air revitalization and food production. Before space use, components' compatibility with reduced gravity was tested.
View Article and Find Full Text PDFMetagenome community analyses, driven by the continued development in sequencing technology, is rapidly providing insights in many aspects of microbiology and becoming a cornerstone tool. Illumina, Oxford Nanopore Technologies (ONT) and Pacific Biosciences (PacBio) are the leading technologies, each with their own advantages and drawbacks. Illumina provides accurate reads at a low cost, but their length is too short to close bacterial genomes.
View Article and Find Full Text PDFThe advancement of regenerative life support systems (RLSS) is crucial to allow long-distance space travel. Within the Micro-Ecological Life Support System Alternative (MELiSSA), efficient nitrogen recovery from urine and other waste streams is vital to produce liquid fertilizer to feed food and oxygen production in subsequent photoautotrophic processes. This study explores the effects of ionizing radiation on nitrogen cycle bacteria that transform urea to nitrate.
View Article and Find Full Text PDFRegenerative life support systems (RLSS) will play a vital role in achieving self-sufficiency during long-distance space travel. Urine conversion into a liquid nitrate-based fertilizer is a key process in most RLSS. This study describes the effects of simulated microgravity (SMG) on Comamonas testosteroni, Nitrosomonas europaea, Nitrobacter winogradskyi and a tripartite culture of the three, in the context of nitrogen recovery for the Micro-Ecological Life Support System Alternative (MELiSSA).
View Article and Find Full Text PDFRadiotherapy is a commonly employed treatment for colorectal cancer, yet its radiotoxicity-related impact on healthy tissues raises significant health concerns. This highlights the need to use radioprotective agents to mitigate these side effects. This review presents the current landscape of human translational radiobiology, outlining the limitations of existing models and proposing engineering solutions.
View Article and Find Full Text PDFColorectal cancer (CRC) is one of the most commonly diagnosed cancers and poses a major burden on the human health worldwide. At the moment, treatment of CRC consists of surgery in combination with (neo)adjuvant chemotherapy and/or radiotherapy. More recently, immune checkpoint blockers (ICBs) have also been approved for CRC treatment.
View Article and Find Full Text PDFLong-term human space exploration missions require environmental control and closed Life Support Systems (LSS) capable of producing and recycling resources, thus fulfilling all the essential metabolic needs for human survival in harsh space environments, both during travel and on orbital/planetary stations. This will become increasingly necessary as missions reach farther away from Earth, thereby limiting the technical and economic feasibility of resupplying resources from Earth. Further incorporation of biological elements into state-of-the-art (mostly abiotic) LSS, leading to bioregenerative LSS (BLSS), is needed for additional resource recovery, food production, and waste treatment solutions, and to enable more self-sustainable missions to the Moon and Mars.
View Article and Find Full Text PDFMicrobes are the Earth life forms that have the highest degree of adaptability to survive, live, or even proliferate in very hostile environments. It is even stated that microbes can cope with any extreme physico-chemical condition and are, therefore, omnipresent all over the Earth: on all the continents, inside its crust and in all its waterbodies. However, our study suggests that there exists areas and even water rich environments on Earth where no life is possible.
View Article and Find Full Text PDFRNA-sequencing for whole transcriptome analysis requires high-quality RNA in adequate amounts, which can be difficult to generate with low-biomass-producing bacteria where sample volume is limited. We present an RNA extraction protocol for low-biomass-producing autotrophic bacteria Nitrosomonas europaea and Nitrobacter winogradskyi cultures. We describe steps for sample collection, lysozyme-based enzymatic lysis, and a commercial silica-column-based RNA extraction.
View Article and Find Full Text PDFSpace experiments are a technically challenging but a scientifically important part of astrobiology and astrochemistry research. The International Space Station (ISS) is an excellent example of a highly successful and long-lasting research platform for experiments in space, that has provided a wealth of scientific data over the last two decades. However, future space platforms present new opportunities to conduct experiments with the potential to address key topics in astrobiology and astrochemistry.
View Article and Find Full Text PDFPelvic irradiation-induced mucositis secondarily leads to dysbiosis, which seriously affects patients' quality of life after treatment. No safe and effective radioprotector or mitigator has yet been approved for clinical therapy. Here, we investigated the potential protective effects of fresh biomass of PCC 8005 against ionizing irradiation-induced mucositis and dysbiosis in respect to benchmark probiotic GG ATCC 53103.
View Article and Find Full Text PDFUranium contamination is a widespread problem caused by natural and anthropogenic activities. Although microorganisms thrive in uranium-contaminated environments, little is known about the actual molecular mechanisms mediating uranium resistance. Here, we investigated the resistance mechanisms driving the adaptation of Cupriavidus metallidurans NA4 to toxic uranium concentrations.
View Article and Find Full Text PDFWe developed a procedure for extracting maximal amounts of high-quality RNA from low-biomass producing (autotrophic) bacteria for experiments where sample volume is limited. Large amounts of high-quality RNA for downstream analyses cannot be obtained using larger quantities of culture volume. The performance of standard commercial silica-column based kit protocols and these procedures amended by ultrasonication or enzymatic lysis were assessed.
View Article and Find Full Text PDFAn important fraction of the currently stored volume of long-lived intermediate-level radioactive waste in Belgium contains large amounts of NaNO homogeneously dispersed in a hard bituminous matrix. Geological disposal of this waste form in a water-saturated sedimentary formation such as Boom Clay will result in the leaching of high concentrations of NaNO, which could cause a geochemical perturbation of the surrounding clay, possibly affecting some of the favorable characteristics of the host formation. In addition, hyper-alkaline conditions are expected for thousands of years, imposed by the cementitious materials used as backfill material.
View Article and Find Full Text PDFEnvironmental uranium pollution due to industries producing naturally occurring radioactive material or nuclear accidents and releases is a global concern. Uranium is hazardous for ecosystems as well as for humans when accumulated through the food chain, through contaminated groundwater and potable water sources, or through inhalation. In particular, uranium pollution pressures microbial communities, which are essential for healthy ecosystems.
View Article and Find Full Text PDFBackground: Although the total number of microbial taxa on Earth is under debate, it is clear that only a small fraction of these has been cultivated and validly named. Evidently, the inability to culture most bacteria outside of very specific conditions severely limits their characterization and further studies. In the last decade, a major part of the solution to this problem has been the use of metagenome sequencing, whereby the DNA of an entire microbial community is sequenced, followed by the in silico reconstruction of genomes of its novel component species.
View Article and Find Full Text PDFThe BR2 nuclear research reactor in Mol, Belgium, runs in successive phases of operation (cycles) and shutdown, whereby a water basin surrounding the reactor vessel undergoes periodic changes in physico-chemical parameters such as flow rate, temperature, and radiation. The aim of this study was to explore the microbial community in this unique environment and to investigate its long-term dynamics using a 16S rRNA amplicon sequencing approach. Results from two sampling campaigns spanning several months showed a clear shift in community profiles: cycles were mostly dominated by two Operational Taxonomic Units (OTUs) assigned to unclassified and , whereas shutdowns were dominated by an OTU assigned to .
View Article and Find Full Text PDFTo enable long-distance space travel, the development of a highly efficient and robust system to recover nutrients from waste streams is imperative. The inability of the current physicochemical-based environmental control and life support system (ECLSS) on the ISS to produce food and to recover water and oxygen at high enough efficiencies results in the need for frequent resupply missions from Earth. Therefore, alternative strategies like biologically-based technologies called bioregenerative life support systems (BLSSs) are in development.
View Article and Find Full Text PDFTwo morphotypes of the cyanobacterial (formerly sp.) strain PCC 8005, denoted as P2 (straight trichomes) and P6 (helical trichomes), were subjected to chronic gamma radiation from spent nuclear fuel (SNF) rods at a dose rate of ca. 80 Gy·h for one mass doubling period (approximately 3 days) under continuous light with photoautotrophic metabolism fully active.
View Article and Find Full Text PDFCupriavidus metallidurans is a model bacterium to study molecular metal resistance mechanisms and its use for the bioremediation of several metals has been shown. However, its mechanisms for radionuclide resistance are unexplored. We investigated the interaction with uranium and associated cellular response to uranium for Cupriavidus metallidurans NA4.
View Article and Find Full Text PDFstrains display a decreased viability when incubated in rich medium at a temperature of 37°C compared to their normal growth temperature of 30°C, a phenomenon coined "temperature-induced mortality and mutagenesis" (TIMM). To scrutinize this aberrant phenotype further, the contributions of specific inducers and protective agents were determined. Different growth media, including lysogeny broth (LB) and Schatz, and components, including casamino acids, in particular amino acids (proline, cysteine, glycine, glutamine, leucine, histidine and phenylalanine) and ammonium, were found to induce TIMM at 37°C.
View Article and Find Full Text PDFThere are still many challenges to overcome for human space exploration beyond low Earth orbit (LEO) (e.g., to the Moon) and for long-term missions (e.
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