1
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Verbeelen T, Fernandez CA, Nguyen TH, Gupta S, Leroy B, Wattiez R, Vlaeminck SE, Leys N, Ganigué R, Mastroleo F. Radiotolerance of N-cycle bacteria and their transcriptomic response to low-dose space-analogue ionizing irradiation. iScience 2024; 27:109596. [PMID: 38638570 PMCID: PMC11024918 DOI: 10.1016/j.isci.2024.109596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/08/2024] [Accepted: 03/25/2024] [Indexed: 04/20/2024] Open
Abstract
The 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. In particular, we assess the radiotolerance of Comamonas testosteroni, Nitrosomonas europaea, and Nitrobacter winogradskyi after exposure to acute γ-irradiation. Moreover, a comprehensive whole transcriptome analysis elucidates the effects of spaceflight-analogue low-dose ionizing radiation on the individual axenic strains and on their synthetic community o. This research sheds light on how the spaceflight environment could affect ureolysis and nitrification processes from a transcriptomic perspective.
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Affiliation(s)
- Tom Verbeelen
- Nuclear Medical Applications (NMA), Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Celia Alvarez Fernandez
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Thanh Huy Nguyen
- Department of Proteomics and Microbiology, University of Mons, Av. Du Champs de Mars 6, 7000 Mons, Belgium
| | - Surya Gupta
- Nuclear Medical Applications (NMA), Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium
| | - Baptiste Leroy
- Department of Proteomics and Microbiology, University of Mons, Av. Du Champs de Mars 6, 7000 Mons, Belgium
| | - Ruddy Wattiez
- Department of Proteomics and Microbiology, University of Mons, Av. Du Champs de Mars 6, 7000 Mons, Belgium
| | - Siegfried E. Vlaeminck
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Centre for Advanced Process Technology for Urban REsource Recovery (CAPTURE), Frieda Saeysstraat 1, 9052 Ghent, Belgium
| | - Natalie Leys
- Nuclear Medical Applications (NMA), Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium
| | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
- Centre for Advanced Process Technology for Urban REsource Recovery (CAPTURE), Frieda Saeysstraat 1, 9052 Ghent, Belgium
| | - Felice Mastroleo
- Nuclear Medical Applications (NMA), Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium
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2
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Cassaro A, Pacelli C, Baqué M, Maturilli A, Böttger U, Fujimori A, Moeller R, de Vera JPP, Onofri S. Spectroscopic investigations of fungal biomarkers after exposure to heavy ion irradiation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 302:123073. [PMID: 37453382 DOI: 10.1016/j.saa.2023.123073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/18/2023]
Abstract
The main objective of the ongoing and future space exploration missions is the search for traces of extant or extinct life (biomarkers) on Mars. One of the main limiting factors on the survival of Earth-like life is the presence of harmful space radiation, that could damage or modify also biomolecules, therefore understanding the effects of radiation on terrestrial biomolecules stability and detectability is of utmost importance. Which terrestrial molecules could be preserved in a Martian radiation scenario? Here, we investigated the potential endurance of fungal biomolecules, by exposing de-hydrated colonies of the Antarctic cryptoendolithic black fungus Cryomyces antarcticus mixed with Antarctic sandstone and with two Martian regolith analogues to increasing doses (0, 250 and 1000 Gy) of accelerated ions, namely iron (Fe), argon (Ar) and helium (He) ions. We analyzed the feasibility to detect fungal compounds with Raman and Infrared spectroscopies after exposure to these space-relevant radiations.
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Affiliation(s)
- A Cassaro
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy
| | - C Pacelli
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy; Italian Space Agency, Via del Politecnico snc, Rome, Italy.
| | - M Baqué
- German Aerospace Center (DLR), Institute of Planetary Research, Planetary Laboratories Department Berlin, Germany
| | - A Maturilli
- German Aerospace Center (DLR), Institute of Planetary Research, Planetary Laboratories Department Berlin, Germany
| | - U Böttger
- German Aerospace Center (DLR), Institute of Optical Sensor Systems Berlin, Germany
| | - A Fujimori
- Molecular and Cellular Radiation Biology Group, Department of Basic Medical Sciences for Radiation Damages, NIRS/QST, Chiba, Japan
| | - R Moeller
- German Aerospace Center, Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, DLR, Linder Höhe, D-51147 Köln, Germany; University of Applied Sciences Bonn-Rhein-Sieg (BRSU), Natural Sciences, von-Liebig-Straße 20, D-53359 Rheinbach, Germany
| | - J-P P de Vera
- German Aerospace Center (DLR), Space Operations and Astronaut Training, MUSC, Linder Höhe, D-51147 Köln, Germany; University of Potsdam, Institute for Biochemistry and Biology, WG Biodiversity/ Systematic Botany, Maulbeerallee 1, 14469 Potsdam, Germany
| | - S Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy
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3
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Naz N, Harandi BF, Newmark J, Kounaves SP. Microbial growth in actual martian regolith in the form of Mars meteorite EETA79001. COMMUNICATIONS EARTH & ENVIRONMENT 2023; 4:381. [PMID: 38665180 PMCID: PMC11041791 DOI: 10.1038/s43247-023-01042-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 10/04/2023] [Indexed: 04/28/2024]
Abstract
Studies to understand the growth of organisms on Mars are hampered by the use of simulants to duplicate martian mineralogy and chemistry. Even though such materials are improving, no terrestrial simulant can replace a real martian sample. Here we report the use of actual martian regolith, in the form of Mars meteorite EETA79001 sawdust, to demonstrate its ability to support the growth of four microorganisms, E. coli. Eucapsis sp., Chr20-20201027-1, and P. halocryophilus, for up to 23 days under terrestrial conditions using regolith:water ratios from 4:1 to 1:10. If the EETA79001 sawdust is widely representative of regolith on the martian surface, our results imply that microbial life under appropriate conditions could have been present on Mars in the past and/or today in the subsurface, and that the regolith does not contain any bactericidal agents. The results of our study have implications not only for putative martian microbial life but also for building bio-sustainable human habitats on Mars.
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Affiliation(s)
- Neveda Naz
- Department of Chemistry, Tufts University, Medford, MA 02155 USA
| | - Bijan F. Harandi
- Department of Chemistry, Tufts University, Medford, MA 02155 USA
| | - Jacob Newmark
- Department of Chemistry, Tufts University, Medford, MA 02155 USA
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4
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Chi Y, Wang X, Li F, Zhang Z, Tan P. Aerospace Technology Improves Fermentation Potential of Microorganisms. Front Microbiol 2022; 13:896556. [PMID: 35572688 PMCID: PMC9106405 DOI: 10.3389/fmicb.2022.896556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 03/29/2022] [Indexed: 11/30/2022] Open
Abstract
It is highly possible to obtain high-quality microbial products in appreciable amounts, as aerospace technology is advancing continuously. Genome-wide genetic variations in microorganisms can be triggered by space microgravity and radiation. Mutation rate is high, mutant range is wide, and final mutant character is stable. Therefore, space microorganism breeding is growing to be a new and promising area in microbial science and has greatly propelled the development of fermentation technology. Numerous studies have discovered the following improvements of fermentation potential in microorganisms after exposure to space: (1) reduction in fermentation cycle and increase in growth rate; (2) improvement of mixed fermentation species; (3) increase in bacterial conjugation efficiency and motility; (4) improvement of the bioactivity of various key enzymes and product quality; (5) enhancement of multiple adverse stress resistance; (6) improvement of fermentation metabolites, flavor, appearance, and stability. Aerospace fermentation technology predominantly contributes to bioprocessing in a microgravity environment. Unlike terrestrial fermentation, aerospace fermentation keeps cells suspended in the fluid medium without significant shear forces. Space radiation and microgravity have physical, chemical, and biological effects on mutant microorganisms by causing alternation in fluid dynamics and genome, transcriptome, proteome, and metabolome levels.
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Affiliation(s)
- Yan Chi
- Wuzhoufeng Agricultural Science and Technology Co., Ltd., Yantai, China
| | - Xuejiang Wang
- Wuzhoufeng Agricultural Science and Technology Co., Ltd., Yantai, China
| | - Feng Li
- Wuzhoufeng Agricultural Science and Technology Co., Ltd., Yantai, China
| | - Zhikai Zhang
- Wuzhoufeng Agricultural Science and Technology Co., Ltd., Yantai, China
| | - Peiwen Tan
- Department of Computer Science, University of California, Irvine, Irvine, CA, United States
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5
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Environmental dependence of competitive fitness in rifampin-resistant
rpoB
mutants of
Bacillus subtilis. Appl Environ Microbiol 2022; 88:e0242221. [DOI: 10.1128/aem.02422-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RNA polymerase (RNAP) is a highly conserved macromolecular machine that contributes to the flow of genetic information from genotype to phenotype. In
Bacillus subtilis
, mutations in the
rpoB
gene encoding the β-subunit of RNAP have been shown to alter a number of global phenotypes including growth, utilization of unusual nutrient sources, sporulation, germination, and production of secondary metabolites. In addition, the spectrum of mutations in
rpoB
leading to rifampin resistance (Rif
R
) can change dramatically depending upon the environment to which
B. subtilis
cells or spores are exposed. Rif
R
rpoB
mutations have historically been associated with slower growth and reduced fitness; however, these assessments of fitness were conducted on limited collections of mutants in rich laboratory media that poorly reflect natural environments typically inhabited by
B. subtilis
. Using a novel, deep-sequencing approach in addition to traditional measurements of growth rate, lag time, and pairwise competitions, we demonstrated the competitive advantage of specific
rpoB
alleles differs depending on the growth environment in which they are determined.
IMPORTANCE
Microbial resistance to antibiotics is a growing threat to public health across the world. Historically, resistance to antibiotics has been associated with reduced fitness. A growing body of evidence indicates that resistance to rifampin, a frontline antibiotic used to treat mycobacterial and biofilm-associated infections, may increase fitness given an appropriate environment even in the absence of the selective antibiotic. Here we experimentally confirm this phenomenon by directly comparing the fitness of multiple rifampin-resistant mutants of
Bacillus subtilis
in rich LB medium and an asparagine minimal medium. Our research demonstrates that the fitness cost of rifampin resistance can vary greatly depending upon the environment. This has important implications for understanding how microbes develop antimicrobial resistance in the absence of antibiotic selection.
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6
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Leehan JD, Nicholson WL. The Spectrum of Spontaneous Rifampin Resistance Mutations in the Bacillus subtilis rpoB Gene Depends on the Growth Environment. Appl Environ Microbiol 2021; 87:e0123721. [PMID: 34495706 PMCID: PMC8552901 DOI: 10.1128/aem.01237-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/01/2021] [Indexed: 11/20/2022] Open
Abstract
Results from previous investigations into spontaneous rifampin resistance (Rifr) mutations in the Bacillus subtilis rpoB gene suggested that the spectrum of mutations depends on the growth environment. However, these studies were limited by low sample numbers, allowing for the potential distortion of the data by the presence of "jackpot" mutations that may have arisen early in the growth of a population. Here, we addressed this issue by performing fluctuation analyses to assess both the rate and spectrum of Rifr mutations in two distinct media: LB, a complete laboratory medium, and SMMAsn, a minimal medium utilizing l-asparagine as the sole carbon source. We cultivated 60 separate populations under each growth condition and determined the mutation rate to Rifr to be slightly but significantly higher in LB cultures. We then sequenced the relevant regions of rpoB to map the spectrum of Rifr mutations under each growth condition. We found a distinct spectrum of mutations in each medium; LB cultures were dominated by the H482Y mutation (27/53 or 51%), whereas SMMAsn cultures were dominated by the S487L mutation (24/51 or 47%). Furthermore, we found through competition experiments that the relative fitness of the S487L mutant was significantly higher in SMMAsn than in LB medium. We therefore conclude that both the spectrum of Rifr mutations in the B. subtilis rpoB gene and the fitness of resulting mutants are influenced by the growth environment. IMPORTANCE The rpoB gene encodes the beta subunit of RNA polymerase, and mutations in rpoB are key determinants of resistance to the clinically important antibiotic rifampin. We show here that the spectrum of mutations in Bacillus subtilis rpoB depends on the medium in which the cells are cultivated. The results show that the growth environment not only plays a role in natural selection and fitness but also influences the probability of mutation at particular bases within the target gene.
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Affiliation(s)
- Joss D. Leehan
- Department of Microbiology and Cell Science, University of Florida, Merritt Island, Florida, USA
| | - Wayne L. Nicholson
- Department of Microbiology and Cell Science, University of Florida, Merritt Island, Florida, USA
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7
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Verbeelen T, Leys N, Ganigué R, Mastroleo F. Development of Nitrogen Recycling Strategies for Bioregenerative Life Support Systems in Space. Front Microbiol 2021; 12:700810. [PMID: 34721316 PMCID: PMC8548772 DOI: 10.3389/fmicb.2021.700810] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 08/30/2021] [Indexed: 12/03/2022] Open
Abstract
To 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 in situ 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. These systems aim to combine biological and physicochemical processes, which enable in situ water, oxygen, and food production (through the highly efficient recovery of minerals from waste streams). Hence, minimalizing the need for external consumables. One of the BLSS initiatives is the European Space Agency's (ESA) Micro-Ecological Life Support System Alternative (MELiSSA). It has been designed as a five-compartment bioengineered system able to produce fresh food and oxygen and to recycle water. As such, it could sustain the needs of a human crew for long-term space exploration missions. A prerequisite for the self-sufficient nature of MELiSSA is the highly efficient recovery of valuable minerals from waste streams. The produced nutrients can be used as a fertilizer for food production. In this review, we discuss the need to shift from the ECLSS to a BLSS, provide a summary of past and current BLSS programs and their unique approaches to nitrogen recovery and processing of urine waste streams. In addition, compartment III of the MELiSSA loop, which is responsible for nitrogen recovery, is reviewed in-depth. Finally, past, current, and future related ground and space demonstration and the space-related challenges for this technology are considered.
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Affiliation(s)
- Tom Verbeelen
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Natalie Leys
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Centre for Advanced Process Technology for Urban REsource Recovery (CAPTURE), Ghent, Belgium
| | - Felice Mastroleo
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
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8
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Proton-Cluster-Beam Lethality and Mutagenicity in Bacillus subtilis Spores. QUANTUM BEAM SCIENCE 2021. [DOI: 10.3390/qubs5030025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The unique energy transfer characteristics of swift cluster ions have attracted the attention of many researchers working on the analysis or processing of material surfaces, but the effects on living organisms remain unclear. We irradiated B. subtilis spores with monomer and cluster proton beams and examined their lethality; the 2 MeV H2+ shows a clearly lower lethality than 340 keV H+, even though both have a comparable linear energy transfer. The 2 MeV H2+ dissociates into a pair of 1 MeV H+ by losing the bonding electrons at the target surface. The estimated internuclear distance and the radial dose distribution suggest that the spread of deposited total energy over two areas separated by just several nanometers greatly diminishes beam lethality and that the energy density in the very center of the trajectory, possibly within a 1 nm radius, has a great impact on lethality. We also performed a whole genome resequencing of the surviving colonies to compare the molecular nature of mutations but failed to find a clear difference in overall characteristics. Our results suggest that cluster beams may be a useful tool for understanding biological effects of high linear energy transfer radiation.
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9
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Effects of Heavy Ion Particle Irradiation on Spore Germination of Bacillus spp. from Extremely Hot and Cold Environments. Life (Basel) 2020; 10:life10110264. [PMID: 33143156 PMCID: PMC7693761 DOI: 10.3390/life10110264] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
Extremophiles are optimal models in experimentally addressing questions about the effects of cosmic radiation on biological systems. The resistance to high charge energy (HZE) particles, and helium (He) ions and iron (Fe) ions (LET at 2.2 and 200 keV/µm, respectively, until 1000 Gy), of spores from two thermophiles, Bacillushorneckiae SBP3 and Bacilluslicheniformis T14, and two psychrotolerants, Bacillus sp. A34 and A43, was investigated. Spores survived He irradiation better, whereas they were more sensitive to Fe irradiation (until 500 Gy), with spores from thermophiles being more resistant to irradiations than psychrotolerants. The survived spores showed different germination kinetics, depending on the type/dose of irradiation and the germinant used. After exposure to He 1000 Gy, D-glucose increased the lag time of thermophilic spores and induced germination of psychrotolerants, whereas L-alanine and L-valine increased the germination efficiency, except alanine for A43. FTIR spectra showed important modifications to the structural components of spores after Fe irradiation at 250 Gy, which could explain the block in spore germination, whereas minor changes were observed after He radiation that could be related to the increased permeability of the inner membranes and alterations of receptor complex structures. Our results give new insights on HZE resistance of extremophiles that are useful in different contexts, including astrobiology.
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10
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Kawaguchi Y, Shibuya M, Kinoshita I, Yatabe J, Narumi I, Shibata H, Hayashi R, Fujiwara D, Murano Y, Hashimoto H, Imai E, Kodaira S, Uchihori Y, Nakagawa K, Mita H, Yokobori SI, Yamagishi A. DNA Damage and Survival Time Course of Deinococcal Cell Pellets During 3 Years of Exposure to Outer Space. Front Microbiol 2020; 11:2050. [PMID: 32983036 PMCID: PMC7479814 DOI: 10.3389/fmicb.2020.02050] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/05/2020] [Indexed: 11/13/2022] Open
Abstract
The hypothesis called “panspermia” proposes an interplanetary transfer of life. Experiments have exposed extremophilic organisms to outer space to test microbe survivability and the panspermia hypothesis. Microbes inside shielding material with sufficient thickness to protect them from UV-irradiation can survive in space. This process has been called “lithopanspermia,” meaning rocky panspermia. We previously proposed sub-millimeter cell pellets (aggregates) could survive in the harsh space environment based on an on-ground laboratory experiment. To test our hypothesis, we placed dried cell pellets of the radioresistant bacteria Deinococcus spp. in aluminum plate wells in exposure panels attached to the outside of the International Space Station (ISS). We exposed microbial cell pellets with different thickness to space environments. The results indicated the importance of the aggregated form of cells for surviving in harsh space environment. We also analyzed the samples exposed to space from 1 to 3 years. The experimental design enabled us to get and extrapolate the survival time course to predict the survival time of Deinococcus radiodurans. Dried deinococcal cell pellets of 500 μm thickness were alive after 3 years of space exposure and repaired DNA damage at cultivation. Thus, cell pellets 1 mm in diameter have sufficient protection from UV and are estimated to endure the space environment for 2–8 years, extrapolating the survival curve and considering the illumination efficiency of the space experiment. Comparison of the survival of different DNA repair-deficient mutants suggested that cell aggregates exposed in space for 3 years suffered DNA damage, which is most efficiently repaired by the uvrA gene and uvdE gene products, which are responsible for nucleotide excision repair and UV-damage excision repair. Collectively, these results support the possibility of microbial cell aggregates (pellets) as an ark for interplanetary transfer of microbes within several years.
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Affiliation(s)
- Yuko Kawaguchi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Mio Shibuya
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Iori Kinoshita
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Jun Yatabe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Issay Narumi
- Faculty of Life Sciences, Toyo University, Oura-gun, Japan
| | - Hiromi Shibata
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan
| | - Risako Hayashi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Daisuke Fujiwara
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Yuka Murano
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Hirofumi Hashimoto
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan
| | - Eiichi Imai
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Japan
| | - Satoshi Kodaira
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yukio Uchihori
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Kazumichi Nakagawa
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan
| | - Hajime Mita
- Department of Life, Environment and Applied Chemistry, Faculty of Engineering, Fukuoka Institute of Technology, Fukuoka, Japan
| | - Shin-Ichi Yokobori
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Akihiko Yamagishi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan.,Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan
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11
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Cortesão M, de Haas A, Unterbusch R, Fujimori A, Schütze T, Meyer V, Moeller R. Aspergillus niger Spores Are Highly Resistant to Space Radiation. Front Microbiol 2020; 11:560. [PMID: 32318041 PMCID: PMC7146846 DOI: 10.3389/fmicb.2020.00560] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/16/2020] [Indexed: 12/20/2022] Open
Abstract
The filamentous fungus Aspergillus niger is one of the main contaminants of the International Space Station (ISS). It forms highly pigmented, airborne spores that have thick cell walls and low metabolic activity, enabling them to withstand harsh conditions and colonize spacecraft surfaces. Whether A. niger spores are resistant to space radiation, and to what extent, is not yet known. In this study, spore suspensions of a wild-type and three mutant strains (with defects in pigmentation, DNA repair, and polar growth control) were exposed to X-rays, cosmic radiation (helium- and iron-ions) and UV-C (254 nm). To assess the level of resistance and survival limits of fungal spores in a long-term interplanetary mission scenario, we tested radiation doses up to 1000 Gy and 4000 J/m2. For comparison, a 360-day round-trip to Mars yields a dose of 0.66 ± 0.12 Gy. Overall, wild-type spores of A. niger were able to withstand high doses of X-ray (LD90 = 360 Gy) and cosmic radiation (helium-ion LD90 = 500 Gy; and iron-ion LD90 = 100 Gy). Drying the spores before irradiation made them more susceptible toward X-ray radiation. Notably, A. niger spores are highly resistant to UV-C radiation (LD90 = 1038 J/m2), which is significantly higher than that of other radiation-resistant microorganisms (e.g., Deinococcus radiodurans). In all strains, UV-C treated spores (1000 J/m2) were shown to have decreased biofilm formation (81% reduction in wild-type spores). This study suggests that A. niger spores might not be easily inactivated by exposure to space radiation alone and that current planetary protection guidelines should be revisited, considering the high resistance of fungal spores.
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Affiliation(s)
- Marta Cortesão
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Aram de Haas
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Rebecca Unterbusch
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Akira Fujimori
- Department of Basic Medical Sciences for Radiation Damages, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tabea Schütze
- Chair of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Vera Meyer
- Chair of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Ralf Moeller
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
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12
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Netea MG, Domínguez-Andrés J, Eleveld M, op den Camp HJM, van der Meer JWM, Gow NAR, de Jonge MI. Immune recognition of putative alien microbial structures: Host-pathogen interactions in the age of space travel. PLoS Pathog 2020; 16:e1008153. [PMID: 31999804 PMCID: PMC6991955 DOI: 10.1371/journal.ppat.1008153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human space travel is on the verge of visiting Mars and, in the future, even more distant places in the solar system. These journeys will be also made by terrestrial microorganisms (hitchhiking on the bodies of astronauts or on scientific instruments) that, upon arrival, will come into contact with new planetary environments, despite the best measures to prevent contamination. These microorganisms could potentially adapt and grow in the new environments and subsequently recolonize and infect astronauts. An even more challenging situation would be if truly alien microorganisms will be present on these solar system bodies: What will be their pathogenic potential, and how would our immune host defenses react? It will be crucial to anticipate these situations and investigate how the immune system of humans might cope with modified terrestrial or alien microbes. We propose several scenarios that may be encountered and how to respond to these challenges.
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Affiliation(s)
- Mihai G. Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
- Department for Genomics & Immunoregulation, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Jorge Domínguez-Andrés
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Marc Eleveld
- Department of Laboratory Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Huub J. M. op den Camp
- Department of Microbiology, Faculty of Science, Radboud University, Nijmegen, the Netherlands
| | - Jos W. M. van der Meer
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Neil A. R. Gow
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Marien I. de Jonge
- Department of Laboratory Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
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13
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Single-cell analysis reveals individual spore responses to simulated space vacuum. NPJ Microgravity 2018; 4:26. [PMID: 30534587 PMCID: PMC6279783 DOI: 10.1038/s41526-018-0059-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 10/23/2018] [Indexed: 02/07/2023] Open
Abstract
Outer space is a challenging environment for all forms of life, and dormant spores of bacteria have been frequently used to study the survival of terrestrial life in a space journey. Previous work showed that outer space vacuum alone can kill bacterial spores. However, the responses and mechanisms of resistance of individual spores to space vacuum are unclear. Here, we examined spores’ molecular changes under simulated space vacuum (~10−5 Pa) using micro-Raman spectroscopy and found that this vacuum did not cause significant denaturation of spore protein. Then, live-cell microscopy was developed to investigate the temporal events during germination, outgrowth, and growth of individual Bacillus spores. The results showed that after exposure to simulated space vacuum for 10 days, viability of spores of two Bacillus species was reduced up to 35%, but all spores retained their large Ca2+-dipicolinic acid depot. Some of the killed spores did not germinate, and the remaining germinated but did not proceed to vegetative growth. The vacuum treatment slowed spore germination, and changed average times of all major germination events. In addition, viable vacuum-treated spores exhibited much greater sensitivity than untreated spores to dry heat and hyperosmotic stress. Among spores’ resistance mechanisms to high vacuum, DNA-protective α/β−type small acid-soluble proteins, and non-homologous end joining and base excision repair of DNA played the most important roles, especially against multiple cycles of vacuum treatment. Overall, these results give new insight into individual spore’s responses to space vacuum and provide new techniques for microorganism analysis at the single-cell level.
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14
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Veras D, Armstrong DJ, Blake JA, Gutiérrez-Marcos JF, Jackson AP, Schäefer H. Dynamical and Biological Panspermia Constraints Within Multi-planet Exosystems. ASTROBIOLOGY 2018; 18:1106-1122. [PMID: 30095987 DOI: 10.1089/ast.2017.1786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
As discoveries of multiple planets in the habitable zone of their parent star mount, developing analytical techniques to quantify extrasolar intra-system panspermia will become increasingly important. Here, we provide user-friendly prescriptions that describe the asteroid impact characteristics which would be necessary to transport life both inwards and outwards within these systems within a single framework. Our focus is on projectile generation and delivery and our expressions are algebraic, eliminating the need for the solution of differential equations. We derive a probability distribution function for life-bearing debris to reach a planetary orbit, and describe the survival of micro-organisms during planetary ejection, their journey through interplanetary space, and atmospheric entry.
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Affiliation(s)
- Dimitri Veras
- 1 Centre for Exoplanets and Habitability, University of Warwick , Coventry, United Kingdom
- 2 Department of Physics, University of Warwick , Coventry, United Kingdom
| | - David J Armstrong
- 1 Centre for Exoplanets and Habitability, University of Warwick , Coventry, United Kingdom
- 2 Department of Physics, University of Warwick , Coventry, United Kingdom
| | - James A Blake
- 1 Centre for Exoplanets and Habitability, University of Warwick , Coventry, United Kingdom
- 2 Department of Physics, University of Warwick , Coventry, United Kingdom
| | - Jose F Gutiérrez-Marcos
- 1 Centre for Exoplanets and Habitability, University of Warwick , Coventry, United Kingdom
- 3 School of Life Sciences, University of Warwick , Coventry, United Kingdom
| | - Alan P Jackson
- 4 Centre for Planetary Sciences, University of Toronto at Scarborough , Toronto, Canada
- 5 School of Earth and Space Exploration, Arizona State University , Tempe, Arizona
| | - Hendrik Schäefer
- 1 Centre for Exoplanets and Habitability, University of Warwick , Coventry, United Kingdom
- 3 School of Life Sciences, University of Warwick , Coventry, United Kingdom
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15
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Verseux C, Baqué M, Cifariello R, Fagliarone C, Raguse M, Moeller R, Billi D. Evaluation of the Resistance of Chroococcidiopsis spp. to Sparsely and Densely Ionizing Irradiation. ASTROBIOLOGY 2017; 17:118-125. [PMID: 28151689 DOI: 10.1089/ast.2015.1450] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Studying the resistance of cyanobacteria to ionizing radiation provides relevant information regarding astrobiology-related topics including the search for life on Mars, lithopanspermia, and biological life-support systems. Here, we report on the resistance of desert cyanobacteria of the genus Chroococcidiopsis, which were exposed (as part of the STARLIFE series of experiments) in both hydrated and dried states to ionizing radiation with different linear energy transfer values (0.2 to 200 keV/μm). Irradiation with up to 1 kGy of He or Si ions, 2 kGy of Fe ions, 5 kGy of X-rays, or 11.59 kGy of γ rays (60Co) did not eradicate Chroococcidiopsis populations, nor did it induce detectable damage to DNA or plasma membranes. The relevance of these results for astrobiology is briefly discussed. Key Words: Ionizing radiation-Linear energy transfer-Lithopanspermia-Cyanobacterial radioresistance-Chroococcidiopsis-Mars. Astrobiology 17, 118-125.
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Affiliation(s)
- Cyprien Verseux
- 1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy
| | - Mickael Baqué
- 1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy
- 2 Astrobiological Laboratories Research Group, Institute of Planetary Research , Management and Infrastructure, German Aerospace Center (DLR), Berlin, Germany
| | - Riccardo Cifariello
- 1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy
| | - Claudia Fagliarone
- 1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy
| | - Marina Raguse
- 3 Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine , German Aerospace Center (DLR), Cologne, Germany
| | - Ralf Moeller
- 3 Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine , German Aerospace Center (DLR), Cologne, Germany
| | - Daniela Billi
- 1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy
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16
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Improvement of Biological Indicators by Uniformly Distributing Bacillus subtilis Spores in Monolayers To Evaluate Enhanced Spore Decontamination Technologies. Appl Environ Microbiol 2016; 82:2031-2038. [PMID: 26801572 DOI: 10.1128/aem.03934-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/14/2016] [Indexed: 11/20/2022] Open
Abstract
Novel decontamination technologies, including cold low-pressure plasma and blue light (400 nm), are promising alternatives to conventional surface decontamination methods. However, the standardization of the assessment of such sterilization processes remains to be accomplished. Bacterial endospores of the genera Bacillus and Geobacillus are frequently used as biological indicators (BIs) of sterility. Ensuring standardized and reproducible BIs for reliable testing procedures is a significant problem in industrial settings. In this study, an electrically driven spray deposition device was developed, allowing fast, reproducible, and homogeneous preparation of Bacillus subtilis 168 spore monolayers on glass surfaces. A detailed description of the structural design as well as the operating principle of the spraying device is given. The reproducible formation of spore monolayers of up to 5 × 10(7) spores per sample was verified by scanning electron microscopy. Surface inactivation studies revealed that monolayered spores were inactivated by UV-C (254 nm), low-pressure argon plasma (500 W, 10 Pa, 100 standard cubic cm per min), and blue light (400 nm) significantly faster than multilayered spores were. We have thus succeeded in the uniform preparation of reproducible, highly concentrated spore monolayers with the potential to generate BIs for a variety of nonpenetrating surface decontamination techniques.
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17
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Xing Y, Li A, Felker DL, Burggraf LW. Nanoscale structural and mechanical analysis of Bacillus anthracis spores inactivated with rapid dry heating. Appl Environ Microbiol 2014; 80:1739-49. [PMID: 24375142 PMCID: PMC3957622 DOI: 10.1128/aem.03483-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 12/21/2013] [Indexed: 11/20/2022] Open
Abstract
Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating.
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Affiliation(s)
- Yun Xing
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee, USA
| | - Alex Li
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
| | - Daniel L. Felker
- Department of Systems Engineering & Management, Air Force Institute of Technology, WPAFB, Dayton, Ohio, USA
| | - Larry W. Burggraf
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
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18
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Stapelmann K, Fiebrandt M, Raguse M, Awakowicz P, Reitz G, Moeller R. Utilization of low-pressure plasma to inactivate bacterial spores on stainless steel screws. ASTROBIOLOGY 2013; 13:597-606. [PMID: 23768085 PMCID: PMC3713438 DOI: 10.1089/ast.2012.0949] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 04/12/2013] [Indexed: 05/22/2023]
Abstract
A special focus area of planetary protection is the monitoring, control, and reduction of microbial contaminations that are detected on spacecraft components and hardware during and after assembly. In this study, wild-type spores of Bacillus pumilus SAFR-032 (a persistent spacecraft assembly facility isolate) and the laboratory model organism B. subtilis 168 were used to study the effects of low-pressure plasma, with hydrogen alone and in combination with oxygen and evaporated hydrogen peroxide as a process gas, on spore survival, which was determined by a colony formation assay. Spores of B. pumilus SAFR-032 and B. subtilis 168 were deposited with an aseptic technique onto the surface of stainless steel screws to simulate a spore-contaminated spacecraft hardware component, and were subsequently exposed to different plasmas and hydrogen peroxide conditions in a very high frequency capacitively coupled plasma reactor (VHF-CCP) to reduce the spore burden. Spores of the spacecraft isolate B. pumilus SAFR-032 were significantly more resistant to plasma treatment than spores of B. subtilis 168. The use of low-pressure plasma with an additional treatment of evaporated hydrogen peroxide also led to an enhanced spore inactivation that surpassed either single treatment when applied alone, which indicates the potential application of this method as a fast and suitable way to reduce spore-contaminated spacecraft hardware components for planetary protection purposes.
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Affiliation(s)
- Katharina Stapelmann
- Ruhr University Bochum (RUB), Institute for Electrical Engineering and Plasma Technology (AEPT), Bochum, Germany
| | - Marcel Fiebrandt
- Ruhr University Bochum (RUB), Institute for Electrical Engineering and Plasma Technology (AEPT), Bochum, Germany
| | - Marina Raguse
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Cologne (Köln), Germany
| | - Peter Awakowicz
- Ruhr University Bochum (RUB), Institute for Electrical Engineering and Plasma Technology (AEPT), Bochum, Germany
| | - Günther Reitz
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Cologne (Köln), Germany
| | - Ralf Moeller
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Cologne (Köln), Germany
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19
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Moeller R, Reitz G, Li Z, Klein S, Nicholson WL. Multifactorial resistance of Bacillus subtilis spores to high-energy proton radiation: role of spore structural components and the homologous recombination and non-homologous end joining DNA repair pathways. ASTROBIOLOGY 2012; 12:1069-77. [PMID: 23088412 PMCID: PMC3491616 DOI: 10.1089/ast.2012.0890] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The space environment contains high-energy charged particles (e.g., protons, neutrons, electrons, α-particles, heavy ions) emitted by the Sun and galactic sources or trapped in the radiation belts. Protons constitute the majority (87%) of high-energy charged particles. Spores of Bacillus species are one of the model systems used for astro- and radiobiological studies. In this study, spores of different Bacillus subtilis strains were used to study the effects of high energetic proton irradiation on spore survival. Spores of the wild-type B. subtilis strain [mutants deficient in the homologous recombination (HR) and non-homologous end joining (NHEJ) DNA repair pathways and mutants deficient in various spore structural components such as dipicolinic acid (DPA), α/β-type small, acid-soluble spore protein (SASP) formation, spore coats, pigmentation, or spore core water content] were irradiated as air-dried multilayers on spacecraft-qualified aluminum coupons with 218 MeV protons [with a linear energy transfer (LET) of 0.4 keV/μm] to various final doses up to 2500 Gy. Spores deficient in NHEJ- and HR-mediated DNA repair were significantly more sensitive to proton radiation than wild-type spores, indicating that both HR and NHEJ DNA repair pathways are needed for spore survival. Spores lacking DPA, α/β-type SASP, or with increased core water content were also significantly more sensitive to proton radiation, whereas the resistance of spores lacking pigmentation or spore coats was essentially identical to that of the wild-type spores. Our results indicate that α/β-type SASP, core water content, and DPA play an important role in spore resistance to high-energy proton irradiation, suggesting their essential function as radioprotectants of the spore interior.
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Affiliation(s)
- Ralf Moeller
- German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Cologne, Germany.
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20
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Wassmann M, Moeller R, Rabbow E, Panitz C, Horneck G, Reitz G, Douki T, Cadet J, Stan-Lotter H, Cockell CS, Rettberg P. Survival of spores of the UV-resistant Bacillus subtilis strain MW01 after exposure to low-earth orbit and simulated martian conditions: data from the space experiment ADAPT on EXPOSE-E. ASTROBIOLOGY 2012; 12:498-507. [PMID: 22680695 DOI: 10.1089/ast.2011.0772] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In the space experiment "Molecular adaptation strategies of microorganisms to different space and planetary UV climate conditions" (ADAPT), bacterial endospores of the highly UV-resistant Bacillus subtilis strain MW01 were exposed to low-Earth orbit (LEO) and simulated martian surface conditions for 559 days on board the European Space Agency's exposure facility EXPOSE-E, mounted outside the International Space Station. The survival of B. subtilis MW01 spores from both assays (LEO and simulated martian conditions) was determined by a colony-formation assay after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110 nm) as well as the martian UV spectrum (λ≥200 nm) was the most deleterious factor applied; in some samples only a few spore survivors were recovered from B. subtilis MW01 spores exposed in monolayers. However, if shielded from solar irradiation, about 8% of MW01 spores survived in LEO conditions, and 100% survived in simulated martian conditions, compared to the laboratory controls. The results demonstrate the effect of shielding against the high inactivation potential of extraterrestrial solar UV radiation, which limits the chances of survival of even the highly UV-resistant strain of B. subtilis MW01 in the harsh environments of outer space and the martian surface.
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Affiliation(s)
- Marko Wassmann
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
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21
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Moeller R, Reitz G, Nicholson The Protect Team WL, Horneck G. Mutagenesis in bacterial spores exposed to space and simulated martian conditions: data from the EXPOSE-E spaceflight experiment PROTECT. ASTROBIOLOGY 2012; 12:457-468. [PMID: 22680692 DOI: 10.1089/ast.2011.0739] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
As part of the PROTECT experiment of the EXPOSE-E mission on board the International Space Station (ISS), the mutagenic efficiency of space was studied in spores of Bacillus subtilis 168. After 1.5 years' exposure to selected parameters of outer space or simulated martian conditions, the rates of induced mutations to rifampicin resistance (Rif(R)) and sporulation deficiency (Spo(-)) were quantified. In all flight samples, both mutations, Rif(R) and Spo(-), were induced and their rates increased by several orders of magnitude. Extraterrestrial solar UV radiation (>110 nm) as well as simulated martian UV radiation (>200 nm) led to the most pronounced increase (up to nearly 4 orders of magnitude); however, mutations were also induced in flight samples shielded from insolation, which were exposed to the same conditions except solar irradiation. Nucleotide sequencing located the Rif(R) mutations in the rpoB gene encoding the β-subunit of RNA polymerase. Mutations isolated from flight and parallel mission ground reference (MGR) samples were exclusively localized to Cluster I. The 21 Rif(R) mutations isolated from the flight experiment showed all a C to T transition and were all localized to one hotspot: H482Y. In mutants isolated from the MGR, the spectrum was wider with predicted amino acid changes at residues Q469K/L/R, H482D/P/R/Y, and S487L. The data show the unique mutagenic power of space and martian surface conditions as a consequence of DNA injuries induced by solar UV radiation and space vacuum or the low pressure of Mars.
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Affiliation(s)
- Ralf Moeller
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR) , Cologne, Germany.
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22
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Nakanishi S, Moore JE, Matsuda M, Goldsmith CE, Coulter WA, Rao JR. Bacterial stress response to environmental radiation relating to the Fukushima radiation discharge event, Japan: will environmental bacteria alter their antibiotic susceptibility profile? ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2012; 76:169-174. [PMID: 22056799 DOI: 10.1016/j.ecoenv.2011.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 09/15/2011] [Accepted: 09/19/2011] [Indexed: 05/31/2023]
Abstract
Antibiotic resistance in clinical pathogens in humans may be traced back to resistance mechanisms in environmental bacteria and any factors, which are likely to alter (upregulate) resistance in environmental organisms, is of potential and eventual consequence to human pathogens. Furthermore, sublethal doses of gamma radiation to environmental organisms may cause sublethal stress and a selective pressure, which may lead to mutational events that alter the bacterium's susceptibility profile. A gamma (γ) radiation simulation experiment was performed to emulate the exposure of four environmental bacteria, including Listeria innocua, Bacillus subtilis, E. coli and Pseudomonas aeruginosa, to levels of radiation in and around Fukushima, Japan, equating to 1, 10 and 100 years equivalence exposure. Alteration to susceptibility to 14 antibiotics was measured as the primary endpoint. There was no significant alteration in the susceptibility of the Gram-positive organisms, whereas both Gram-negative organisms became slightly more susceptible to the antibiotics tested over time. These data indicate that such radiation exposure will not increase the antibiotic resistance profile of these organisms and hence not add to the global public health burden of increased antibiotic resistance in human bacterial pathogens.
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Affiliation(s)
- Shigeyuki Nakanishi
- Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Lisburn Road, Belfast BT9 7AD, Northern Ireland, UK
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23
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Melott AL, Thomas BC. Astrophysical ionizing radiation and Earth: a brief review and census of intermittent intense sources. ASTROBIOLOGY 2011; 11:343-361. [PMID: 21545268 DOI: 10.1089/ast.2010.0603] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review, we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities, ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere; on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. Both photons (e.g., X-rays) and high-energy protons and other nuclei (often called "cosmic rays") constitute hazards. For either species, one of the mechanisms that comes into play even at moderate intensities is the ionization of Earth's atmosphere, which leads through chemical changes (specifically, depletion of stratospheric ozone) to increased ultraviolet B flux from the Sun reaching the surface. UVB is extremely hazardous to most life due to its strong absorption by the genetic material DNA and subsequent breaking of chemical bonds. This often leads to mutation or cell death. It is easily lethal to the microorganisms that lie at the base of the food chain in the ocean. We enumerate the known sources of radiation and characterize their intensities at Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval," our best estimate of how often a major extinction-level event is probable given the current state of knowledge; we base these estimates on computed or expected depletion of stratospheric ozone. In general, moderate-level events are dominated by the Sun, but the far more severe infrequent events are probably dominated by gamma-ray bursts and supernovae. We note for the first time that so-called "short-hard" gamma-ray bursts are a substantial threat, comparable in magnitude to supernovae and greater than that of the higher-luminosity long bursts considered in most past work. Given their precursors, short bursts may come with little or no warning.
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Affiliation(s)
- Adrian L Melott
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA.
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Role of the Nfo and ExoA apurinic/apyrimidinic endonucleases in radiation resistance and radiation-induced mutagenesis of Bacillus subtilis spores. J Bacteriol 2011; 193:2875-9. [PMID: 21441501 DOI: 10.1128/jb.00134-11] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The roles of DNA repair by apurinic/apyrimidinic (AP) endonucleases alone, and together with DNA protection by α/β-type small acid-soluble spore proteins (SASP), in Bacillus subtilis spore resistance to different types of radiation have been studied. Spores lacking both AP endonucleases (Nfo and ExoA) and major SASP were significantly more sensitive to 254-nm UV-C, environmental UV (>280 nm), X-ray exposure, and high-energy charged (HZE)-particle bombardment and had elevated mutation frequencies compared to those of wild-type spores and spores lacking only one or both AP endonucleases or major SASP. These findings further implicate AP endonucleases and α/β-type SASP in repair and protection, respectively, of spore DNA against effects of UV and ionizing radiation.
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