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Rice KC, Davis KAT. Brief Communication: Confocal microscopy of oral streptococcal biofilms grown in simulated microgravity using a random positioning machine. NPJ Microgravity 2024; 10:89. [PMID: 39251626 DOI: 10.1038/s41526-024-00427-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 08/14/2024] [Indexed: 09/11/2024] Open
Abstract
Biofilms are a concern for spaceflight missions, given their propensity for biofouling systems and their potential threat to astronaut health. Herein, we describe a random positioning machine-based method for growing fluorescent protein-expressing streptococcal biofilms under simulated microgravity. Biofilms can be subsequently imaged by confocal microscopy without further manipulation, minimizing disruption of architecture. This methodology could be adaptable to other bacteria, potentially standardizing biofilm growth and study under simulated microgravity.
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Affiliation(s)
- Kelly C Rice
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, 32611, USA.
| | - Ke Aira T Davis
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, 32611, USA
- Health Sciences (Biotechnology), Central Georgia Technical College, Macon, GA, 31206, USA
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2
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Nickerson CA, McLean RJC, Barrila J, Yang J, Thornhill SG, Banken LL, Porterfield DM, Poste G, Pellis NR, Ott CM. Microbiology of human spaceflight: microbial responses to mechanical forces that impact health and habitat sustainability. Microbiol Mol Biol Rev 2024:e0014423. [PMID: 39158275 DOI: 10.1128/mmbr.00144-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2024] Open
Abstract
SUMMARYUnderstanding the dynamic adaptive plasticity of microorganisms has been advanced by studying their responses to extreme environments. Spaceflight research platforms provide a unique opportunity to study microbial characteristics in new extreme adaptational modes, including sustained exposure to reduced forces of gravity and associated low fluid shear force conditions. Under these conditions, unexpected microbial responses occur, including alterations in virulence, antibiotic and stress resistance, biofilm formation, metabolism, motility, and gene expression, which are not observed using conventional experimental approaches. Here, we review biological and physical mechanisms that regulate microbial responses to spaceflight and spaceflight analog environments from both the microbe and host-microbe perspective that are relevant to human health and habitat sustainability. We highlight instrumentation and technology used in spaceflight microbiology experiments, their limitations, and advances necessary to enable next-generation research. As spaceflight experiments are relatively rare, we discuss ground-based analogs that mimic aspects of microbial responses to reduced gravity in spaceflight, including those that reduce mechanical forces of fluid flow over cell surfaces which also simulate conditions encountered by microorganisms during their terrestrial lifecycles. As spaceflight mission durations increase with traditional astronauts and commercial space programs send civilian crews with underlying health conditions, microorganisms will continue to play increasingly critical roles in health and habitat sustainability, thus defining a new dimension of occupational health. The ability of microorganisms to adapt, survive, and evolve in the spaceflight environment is important for future human space endeavors and provides opportunities for innovative biological and technological advances to benefit life on Earth.
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Affiliation(s)
- Cheryl A Nickerson
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, Arizona, USA
| | - Robert J C McLean
- Department of Biology, Texas State University, San Marcos, Texas, USA
| | - Jennifer Barrila
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, Arizona, USA
| | - Jiseon Yang
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, Arizona, USA
| | | | - Laura L Banken
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, Arizona, USA
| | - D Marshall Porterfield
- Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, Indiana, USA
| | - George Poste
- Complex Adaptive Systems Initiative, Arizona State University, Tempe, Arizona, USA
| | | | - C Mark Ott
- Biomedical Research and Environmental Sciences Division, NASA Johnson Space Center, Houston, Texas, USA
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3
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Hauserman MR, Sullivan LE, James KL, Ferraro MJ, Rice KC. Response of Staphylococcus aureus physiology and Agr quorum sensing to low-shear modeled microgravity. J Bacteriol 2024:e0027224. [PMID: 39120147 DOI: 10.1128/jb.00272-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Accepted: 07/11/2024] [Indexed: 08/10/2024] Open
Abstract
Staphylococcus aureus is commonly isolated from astronauts returning from spaceflight. Previous analysis of omics data from S. aureus low Earth orbit cultures indicated significantly increased expression of the Agr quorum sensing system and its downstream targets in spaceflight samples compared to ground controls. In this current study, the rotary cell culture system (RCCS) was used to investigate the effect of low-shear modeled microgravity (LSMMG) on S. aureus physiology and Agr activity. When cultured in the same growth medium and temperature as the previous spaceflight experiment, S. aureus LSMMG cultures exhibited decreased agr expression and altered growth compared to normal gravity control cultures, which are typically oriented with oxygenation membrane on the bottom of the high aspect rotating vessel (HARV). When S. aureus was grown in an inverted gravity control orientation (oxygenation membrane on top of the HARV), reduced Agr activity was observed relative to both traditional control and LSMMG cultures, signifying that oxygen availability may affect the observed differences in Agr activity. Metabolite assays revealed increased lactate and decreased acetate excretion in both LSMMG and inverted control cultures. Secretomics analysis of LSMMG, control, and inverted control HARV culture supernatants corroborated these results, with inverted and LSMMG cultures exhibiting a decreased abundance of Agr-regulated virulence factors and an increased abundance of proteins expressed in low-oxygen conditions. Collectively, these studies suggest that the orientation of the HARV oxygenation membrane can affect S. aureus physiology and Agr quorum sensing in the RCCS, a variable that should be considered when interpreting data using this ground-based microgravity model.IMPORTANCES. aureus is commonly isolated from astronauts returning from spaceflight and from surfaces within human-inhabited closed environments such as spacecraft. Astronaut health and immune function are significantly altered in spaceflight. Therefore, elucidating the effects of microgravity on S. aureus physiology is critical for assessing its pathogenic potential during long-term human space habitation. These results also highlight the necessity of eliminating potential confounding factors when comparing simulated microgravity model data with actual spaceflight experiments.
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Affiliation(s)
- Matthew R Hauserman
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
| | - Leia E Sullivan
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
| | - Kimberly L James
- Department of Biological Sciences, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Mariola J Ferraro
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
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4
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Bakr MM, Caswell GM, Hussein H, Shamel M, Al-Ankily MM. Considerations for oral and dental tissues in holistic care during long-haul space flights. Front Physiol 2024; 15:1406631. [PMID: 39055690 PMCID: PMC11269229 DOI: 10.3389/fphys.2024.1406631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/12/2024] [Indexed: 07/27/2024] Open
Abstract
The health of astronauts during and after the return from long-haul space missions is paramount. There is plethora of research in the literature about the medical side of astronauts' health, however, the dental and oral health of the space crew seem to be overlooked with limited information in the literature about the effects of the space environment and microgravity on the oral and dental tissues. In this article, we shed some light on the latest available research related to space dentistry and provide some hypotheses that could guide the directions of future research and help maintain the oral health of space crews. We also promote for the importance of regenerative medicine and dentistry as well highlight the opportunities available in the expanding field of bioprinting/biomanufacturing through utilizing the effects of microgravity on stem cells culture techniques. Finally, we provide recommendations for adopting a multidisciplinary approach for oral healthcare during long-haul space flights.
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Affiliation(s)
- Mahmoud M. Bakr
- School of Medicine and Dentistry, Griffith University, Gold Coast, QLD, Australia
| | | | - Habiba Hussein
- Faculty of Dentistry, The British University in Egypt, Cairo, Egypt
| | - Mohamed Shamel
- Faculty of Dentistry, The British University in Egypt, Cairo, Egypt
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Lehr FX, Pavletić B, Glatter T, Heimerl T, Moeller R, Niederholtmeyer H. Enhanced assembly of bacteriophage T7 produced in cell-free reactions under simulated microgravity. NPJ Microgravity 2024; 10:30. [PMID: 38491014 PMCID: PMC10943216 DOI: 10.1038/s41526-024-00378-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/08/2024] [Indexed: 03/18/2024] Open
Abstract
On-demand biomanufacturing has the potential to improve healthcare and self-sufficiency during space missions. Cell-free transcription and translation reactions combined with DNA blueprints can produce promising therapeutics like bacteriophages and virus-like particles. However, how space conditions affect the synthesis and self-assembly of such complex multi-protein structures is unknown. Here, we characterize the cell-free production of infectious bacteriophage T7 virions under simulated microgravity. Rotation in a 2D-clinostat increased the number of infectious particles compared to static controls. Quantitative analyses by mass spectrometry, immuno-dot-blot and real-time PCR showed no significant differences in protein and DNA contents, suggesting enhanced self-assembly of T7 phages in simulated microgravity. While the effects of genuine space conditions on the cell-free synthesis and assembly of bacteriophages remain to be investigated, our findings support the vision of a cell-free synthesis-enabled "astropharmacy".
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Affiliation(s)
- François-Xavier Lehr
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany
| | - Bruno Pavletić
- German Aerospace Center, Institute of Aerospace Medicine, Aerospace Microbiology, Cologne, Germany
- Technical University of Braunschweig, Faculty of Life Sciences, Braunschweig, Germany
| | - Timo Glatter
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Thomas Heimerl
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany
| | - Ralf Moeller
- German Aerospace Center, Institute of Aerospace Medicine, Aerospace Microbiology, Cologne, Germany.
| | - Henrike Niederholtmeyer
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany.
- Technical University of Munich, Campus Straubing for Biotechnology and Sustainability, Straubing, Germany.
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Verbeelen T, Fernandez CA, Nguyen TH, Gupta S, Aarts R, Tabury K, Leroy B, Wattiez R, Vlaeminck SE, Leys N, Ganigué R, Mastroleo F. Whole transcriptome analysis highlights nutrient limitation of nitrogen cycle bacteria in simulated microgravity. NPJ Microgravity 2024; 10:3. [PMID: 38200027 PMCID: PMC10781756 DOI: 10.1038/s41526-024-00345-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
Regenerative 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). Rotary cell culture systems (RCCS) and random positioning machines (RPM) were used as SMG analogues. The transcriptional responses of the cultures were elucidated. For CO2-producing C. testosteroni and the tripartite culture, a PermaLifeTM PL-70 cell culture bag mounted on an in-house 3D-printed holder was applied to eliminate air bubble formation during SMG cultivation. Gene expression changes indicated that the fluid dynamics in SMG caused nutrient and O2 limitation. Genes involved in urea hydrolysis and nitrification were minimally affected, while denitrification-related gene expression was increased. The findings highlight potential challenges for nitrogen recovery in space.
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Affiliation(s)
- Tom Verbeelen
- Nuclear Medical Applications, 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, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium
| | - Raf Aarts
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium
| | - Kevin Tabury
- Nuclear Medical Applications, 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, 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, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium.
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Migration of surface-associated microbial communities in spaceflight habitats. Biofilm 2023; 5:100109. [PMID: 36909662 PMCID: PMC9999172 DOI: 10.1016/j.bioflm.2023.100109] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 02/05/2023] [Accepted: 02/17/2023] [Indexed: 02/26/2023] Open
Abstract
Astronauts are spending longer periods locked up in ships or stations for scientific and exploration spatial missions. The International Space Station (ISS) has been inhabited continuously for more than 20 years and the duration of space stays by crews could lengthen with the objectives of human presence on the moon and Mars. If the environment of these space habitats is designed for the comfort of astronauts, it is also conducive to other forms of life such as embarked microorganisms. The latter, most often associated with surfaces in the form of biofilm, have been implicated in significant degradation of the functionality of pieces of equipment in space habitats. The most recent research suggests that microgravity could increase the persistence, resistance and virulence of pathogenic microorganisms detected in these communities, endangering the health of astronauts and potentially jeopardizing long-duration manned missions. In this review, we describe the mechanisms and dynamics of installation and propagation of these microbial communities associated with surfaces (spatial migration), as well as long-term processes of adaptation and evolution in these extreme environments (phenotypic and genetic migration), with special reference to human health. We also discuss the means of control envisaged to allow a lasting cohabitation between these vibrant microscopic passengers and the astronauts.
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Are Skeletal Muscle Changes during Prolonged Space Flights Similar to Those Experienced by Frail and Sarcopenic Older Adults? LIFE (BASEL, SWITZERLAND) 2022; 12:life12122139. [PMID: 36556504 PMCID: PMC9781047 DOI: 10.3390/life12122139] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/13/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Microgravity exposure causes several physiological and psychosocial alterations that challenge astronauts' health during space flight. Notably, many of these changes are mostly related to physical inactivity influencing different functional systems and organ biology, in particular the musculoskeletal system, dramatically resulting in aging-like phenotypes, such as those occurring in older persons on Earth. In this sense, sarcopenia, a syndrome characterized by the loss in muscle mass and strength due to skeletal muscle unloading, is undoubtedly one of the most critical aging-like adverse effects of microgravity and a prevalent problem in the geriatric population, still awaiting effective countermeasures. Therefore, there is an urgent demand to identify clinically relevant biological markers and to underline molecular mechanisms behind these effects that are still poorly understood. From this perspective, a lesson from Geroscience may help tailor interventions to counteract the adverse effects of microgravity. For instance, decades of studies in the field have demonstrated that in the older people, the clinical picture of sarcopenia remarkably overlaps (from a clinical and biological point of view) with that of frailty, primarily when referred to the physical function domain. Based on this premise, here we provide a deeper understanding of the biological mechanisms of sarcopenia and frailty, which in aging are often considered together, and how these converge with those observed in astronauts after space flight.
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9
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Sun H, Zhou Q, Qiao P, Zhu D, Xin B, Wu B, Tang C. Short-term head-down bed rest microgravity simulation alters salivary microbiome in young healthy men. Front Microbiol 2022; 13:1056637. [PMID: 36439790 PMCID: PMC9684331 DOI: 10.3389/fmicb.2022.1056637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 10/27/2022] [Indexed: 01/03/2024] Open
Abstract
Microgravity influences are prevalent during orbital flight and can adversely affect astronaut physiology. Notably, it may affect the physicochemical properties of saliva and the salivary microbial community. Therefore, this study simulates microgravity in space using a ground-based -6° head-down bed rest (HDBR) test to observe the effects of microgravity on oral salivary secretion function and the salivary microbiome. Sixteen healthy young male volunteers were recruited for the 15-day -6° HDBR test. Non-stimulated whole saliva was collected on day 1 (pre-HDBR), on days 5, 10, and 15 of HDBR, and day 6 of recovery. Salivary pH and salivary flow rate were measured, and the V3-V4 region of the 16S rRNA gene was sequenced and analyzed in 80 saliva samples. The results showed that there were no significant differences in salivary pH, salivary flow rate, and alpha diversity between any two time points. However, beta diversity analysis revealed significant differences between pre-HDBR and the other four time points. After HDBR, the relative abundances of Actinomyces, Parvimonas, Peptostreptococcus, Porphyromonas, Oribacterium, and Capnocytophaga increased significantly, whereas the relative abundances of Neisseria and Haemophilus decreased significantly. However, the relative abundances of Oribacterium and Capnocytophaga did not recover to the pre-HDBR level on day 6 of recovery. Network analysis revealed that the number of relationships between genera decreased, and the positive and negative correlations between genera changed in a complex manner after HDBR and did not reach their original levels on day 6 of recovery. PICRUSt analysis demonstrated that some gene functions of the salivary microbiome also changed after HDBR and remained significantly different from those before HDBR on day 6 of recovery. Collectively, 15 days of -6° HDBR had minimal effect on salivary secretion function but resulted in significant changes in the salivary microbiome, mainly manifested as an increase in oral disease-related bacteria and a decrease in oral health-related commensal bacteria. Further research is required to confirm these oral microbial changes and explore the underlying pathological mechanisms to determine the long-term effects on astronauts embarking on long-duration voyages to outer space.
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Affiliation(s)
- Hui Sun
- 306th Clinical College of PLA, The Fifth Clinical College, Anhui Medical University, Beijing, China
- Department of Stomatology, PLA Strategic Support Force Characteristic Medical Center, Beijing, China
| | - Qian Zhou
- 306th Clinical College of PLA, The Fifth Clinical College, Anhui Medical University, Beijing, China
- Department of Stomatology, PLA Strategic Support Force Characteristic Medical Center, Beijing, China
| | - Pengyan Qiao
- Department of Stomatology, PLA Strategic Support Force Characteristic Medical Center, Beijing, China
| | - Di Zhu
- 306th Clinical College of PLA, The Fifth Clinical College, Anhui Medical University, Beijing, China
- Department of Stomatology, PLA Strategic Support Force Characteristic Medical Center, Beijing, China
| | - Bingmu Xin
- Engineering Research Center of Human Circadian Rhythm and Sleep (Shenzhen), Space Science and Technology Institute (Shenzhen), Shenzhen, China
| | - Bin Wu
- China Astronaut Research and Training Center, Beijing, China
| | - Chuhua Tang
- 306th Clinical College of PLA, The Fifth Clinical College, Anhui Medical University, Beijing, China
- Department of Stomatology, PLA Strategic Support Force Characteristic Medical Center, Beijing, China
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Kumar RK, Singh NK, Balakrishnan S, Parker CW, Raman K, Venkateswaran K. Metabolic modeling of the International Space Station microbiome reveals key microbial interactions. MICROBIOME 2022; 10:102. [PMID: 35791019 PMCID: PMC9258157 DOI: 10.1186/s40168-022-01279-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 04/08/2022] [Indexed: 05/16/2023]
Abstract
BACKGROUND Recent studies have provided insights into the persistence and succession of microbes aboard the International Space Station (ISS), notably the dominance of Klebsiella pneumoniae. However, the interactions between the various microbes aboard the ISS and how they shape the microbiome remain to be clearly understood. In this study, we apply a computational approach to predict possible metabolic interactions in the ISS microbiome and shed further light on its organization. RESULTS Through a combination of a systems-based graph-theoretical approach, and a constraint-based community metabolic modeling approach, we demonstrated several key interactions in the ISS microbiome. These complementary approaches provided insights into the metabolic interactions and dependencies present amongst various microbes in a community, highlighting key interactions and keystone species. Our results showed that the presence of K. pneumoniae is beneficial to many other microorganisms it coexists with, notably those from the Pantoea genus. Species belonging to the Enterobacteriaceae family were often found to be the most beneficial for the survival of other microorganisms in the ISS microbiome. However, K. pneumoniae was found to exhibit parasitic and amensalistic interactions with Aspergillus and Penicillium species, respectively. To prove this metabolic prediction, K. pneumoniae and Aspergillus fumigatus were co-cultured under normal and simulated microgravity, where K. pneumoniae cells showed parasitic characteristics to the fungus. The electron micrography revealed that the presence of K. pneumoniae compromised the morphology of fungal conidia and degenerated its biofilm-forming structures. CONCLUSION Our study underscores the importance of K. pneumoniae in the ISS, and its potential positive and negative interactions with other microbes, including potential pathogens. This integrated modeling approach, combined with experiments, demonstrates the potential for understanding the organization of other such microbiomes, unravelling key organisms and their interdependencies. Video Abstract.
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Affiliation(s)
- Rachita K Kumar
- Robert Bosch Centre for Data Science and Artificial Intelligence (RBCDSAI), Indian Institute of Technology Madras, Chennai, 600 036, India
- Center for Integrative Biology and Systems mEdicine (IBSE), Indian Institute of Technology Madras, Chennai, 600 036, India
| | - Nitin Kumar Singh
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, M/S 89-2, 4800 Oak Grove Dr, Pasadena, CA, CA 91109, USA
| | - Sanjaay Balakrishnan
- Center for Integrative Biology and Systems mEdicine (IBSE), Indian Institute of Technology Madras, Chennai, 600 036, India
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India
| | - Ceth W Parker
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, M/S 89-2, 4800 Oak Grove Dr, Pasadena, CA, CA 91109, USA
| | - Karthik Raman
- Robert Bosch Centre for Data Science and Artificial Intelligence (RBCDSAI), Indian Institute of Technology Madras, Chennai, 600 036, India.
- Center for Integrative Biology and Systems mEdicine (IBSE), Indian Institute of Technology Madras, Chennai, 600 036, India.
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India.
| | - Kasthuri Venkateswaran
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, M/S 89-2, 4800 Oak Grove Dr, Pasadena, CA, CA 91109, USA.
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11
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Kumar RK, Singh NK, Balakrishnan S, Parker CW, Raman K, Venkateswaran K. Metabolic modeling of the International Space Station microbiome reveals key microbial interactions. MICROBIOME 2022. [PMID: 35791019 DOI: 10.1101/2021.09.03.458819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
BACKGROUND Recent studies have provided insights into the persistence and succession of microbes aboard the International Space Station (ISS), notably the dominance of Klebsiella pneumoniae. However, the interactions between the various microbes aboard the ISS and how they shape the microbiome remain to be clearly understood. In this study, we apply a computational approach to predict possible metabolic interactions in the ISS microbiome and shed further light on its organization. RESULTS Through a combination of a systems-based graph-theoretical approach, and a constraint-based community metabolic modeling approach, we demonstrated several key interactions in the ISS microbiome. These complementary approaches provided insights into the metabolic interactions and dependencies present amongst various microbes in a community, highlighting key interactions and keystone species. Our results showed that the presence of K. pneumoniae is beneficial to many other microorganisms it coexists with, notably those from the Pantoea genus. Species belonging to the Enterobacteriaceae family were often found to be the most beneficial for the survival of other microorganisms in the ISS microbiome. However, K. pneumoniae was found to exhibit parasitic and amensalistic interactions with Aspergillus and Penicillium species, respectively. To prove this metabolic prediction, K. pneumoniae and Aspergillus fumigatus were co-cultured under normal and simulated microgravity, where K. pneumoniae cells showed parasitic characteristics to the fungus. The electron micrography revealed that the presence of K. pneumoniae compromised the morphology of fungal conidia and degenerated its biofilm-forming structures. CONCLUSION Our study underscores the importance of K. pneumoniae in the ISS, and its potential positive and negative interactions with other microbes, including potential pathogens. This integrated modeling approach, combined with experiments, demonstrates the potential for understanding the organization of other such microbiomes, unravelling key organisms and their interdependencies. Video Abstract.
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Affiliation(s)
- Rachita K Kumar
- Robert Bosch Centre for Data Science and Artificial Intelligence (RBCDSAI), Indian Institute of Technology Madras, Chennai, 600 036, India
- Center for Integrative Biology and Systems mEdicine (IBSE), Indian Institute of Technology Madras, Chennai, 600 036, India
| | - Nitin Kumar Singh
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, M/S 89-2, 4800 Oak Grove Dr, Pasadena, CA, CA 91109, USA
| | - Sanjaay Balakrishnan
- Center for Integrative Biology and Systems mEdicine (IBSE), Indian Institute of Technology Madras, Chennai, 600 036, India
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India
| | - Ceth W Parker
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, M/S 89-2, 4800 Oak Grove Dr, Pasadena, CA, CA 91109, USA
| | - Karthik Raman
- Robert Bosch Centre for Data Science and Artificial Intelligence (RBCDSAI), Indian Institute of Technology Madras, Chennai, 600 036, India.
- Center for Integrative Biology and Systems mEdicine (IBSE), Indian Institute of Technology Madras, Chennai, 600 036, India.
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India.
| | - Kasthuri Venkateswaran
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, M/S 89-2, 4800 Oak Grove Dr, Pasadena, CA, CA 91109, USA.
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Adaptation to simulated microgravity in Streptococcus mutans. NPJ Microgravity 2022; 8:17. [PMID: 35654802 PMCID: PMC9163064 DOI: 10.1038/s41526-022-00205-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 05/13/2022] [Indexed: 11/08/2022] Open
Abstract
Long-term space missions have shown an increased incidence of oral disease in astronauts’ and as a result, are one of the top conditions predicted to impact future missions. Here we set out to evaluate the adaptive response of Streptococcus mutans (etiological agent of dental caries) to simulated microgravity. This organism has been well studied on earth and treatment strategies are more predictable. Despite this, we are unsure how the bacterium will respond to the environmental stressors in space. We used experimental evolution for 100-days in high aspect ratio vessels followed by whole genome resequencing to evaluate this adaptive response. Our data shows that planktonic S. mutans did evolve variants in three genes (pknB, SMU_399 and SMU_1307c) that can be uniquely attributed to simulated microgravity populations. In addition, collection of data at multiple time points showed mutations in three additional genes (SMU_399, ptsH and rex) that were detected earlier in simulated microgravity populations than in the normal gravity controls, many of which are consistent with other studies. Comparison of virulence-related phenotypes between biological replicates from simulated microgravity and control orientation cultures generally showed few changes in antibiotic susceptibility, while acid tolerance and adhesion varied significantly between biological replicates and decreased as compared to the ancestral populations. Most importantly, our data shows the importance of a parallel normal gravity control, sequencing at multiple time points and the use of biological replicates for appropriate analysis of adaptation in simulated microgravity.
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13
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Kim H, Park B, Park H, Choi I, Rhee M. Low-shear modeled microgravity affects metabolic networks of Escherichia coli O157:H7 EDL933: Further insights into space-microbiology consequences. Food Res Int 2022; 154:111013. [DOI: 10.1016/j.foodres.2022.111013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 02/10/2022] [Accepted: 02/12/2022] [Indexed: 11/04/2022]
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14
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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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15
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Abstract
Microbial research in space is being conducted for almost 50 years now. The closed system of the International Space Station (ISS) has acted as a microbial observatory for the past 10 years, conducting research on adaptation and survivability of microorganisms exposed to space conditions. This adaptation can be either beneficial or detrimental to crew members and spacecraft. Therefore, it becomes crucial to identify the impact of two primary stress conditions, namely, radiation and microgravity, on microbial life aboard the ISS. Elucidating the mechanistic basis of microbial adaptation to space conditions aids in the development of countermeasures against their potentially detrimental effects and allows us to harness their biotechnologically important properties. Several microbial processes have been studied, either in spaceflight or using devices that can simulate space conditions. However, at present, research is limited to only a few microorganisms, and extensive research on biotechnologically important microorganisms is required to make long-term space missions self-sustainable.
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Affiliation(s)
- Swati Bijlani
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Elisa Stephens
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Nitin Kumar Singh
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | | | - Clay C C Wang
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
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16
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Bijlani S, Singh NK, Eedara VVR, Podile AR, Mason CE, Wang CCC, Venkateswaran K. Methylobacterium ajmalii sp. nov., Isolated From the International Space Station. Front Microbiol 2021; 12:639396. [PMID: 33790880 PMCID: PMC8005752 DOI: 10.3389/fmicb.2021.639396] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/22/2021] [Indexed: 11/22/2022] Open
Abstract
Four strains belonging to the family of Methylobacteriaceae were isolated from different locations on the International Space Station (ISS) across two consecutive flights. Of these, three were identified as Gram-negative, rod-shaped, catalase-positive, oxidase-positive, motile bacteria, designated as IF7SW-B2T, IIF1SW-B5, and IIF4SW-B5, whereas the fourth was identified as Methylorubrum rhodesianum. The sequence similarity of these three ISS strains, designated as IF7SW-B2T, IIF1SW-B5, and IIF4SW-B5, was <99.4% for 16S rRNA genes and <97.3% for gyrB gene, with the closest being Methylobacterium indicum SE2.11T. Furthermore, the multi-locus sequence analysis placed these three ISS strains in the same clade of M. indicum. The average nucleotide identity (ANI) values of these three ISS strains were <93% and digital DNA-DNA hybridization (dDDH) values were <46.4% with any described Methylobacterium species. Based on the ANI and dDDH analyses, these three ISS strains were considered as novel species belonging to the genus Methylobacterium. The three ISS strains showed 100% ANI similarity and dDDH values with each other, indicating that these three ISS strains, isolated during various flights and from different locations, belong to the same species. These three ISS strains were found to grow optimally at temperatures from 25 to 30°C, pH 6.0 to 8.0, and NaCl 0 to 1%. Phenotypically, these three ISS strains resemble M. aquaticum and M. terrae since they assimilate similar sugars as sole carbon substrate when compared to other Methylobacterium species. Fatty acid analysis showed that the major fatty acid produced by the ISS strains are C18:1−ω7c and C18:1−ω6c. The predominant quinone was ubiquinone 10, and the major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and an unidentified lipid. Therefore, based on genomic, phylogenetic, biochemical, and fatty acid analyses, strains IF7SW-B2T, IIF1SW-B5, and IIF4SW-B5, are assigned to a novel species within the genus Methylobacterium, and the name Methylobacterium ajmalii sp. nov. is proposed. The type strain is IF7SW-B2T (NRRL B-65601T and LMG 32165T).
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Affiliation(s)
- Swati Bijlani
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Nitin K Singh
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
| | - V V Ramprasad Eedara
- Department of Plant Science, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Appa Rao Podile
- Department of Plant Science, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Christopher E Mason
- WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, NY, United States
| | - Clay C C Wang
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Kasthuri Venkateswaran
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
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17
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Green MJ, Aylott JW, Williams P, Ghaemmaghami AM, Williams PM. Immunity in Space: Prokaryote Adaptations and Immune Response in Microgravity. Life (Basel) 2021; 11:life11020112. [PMID: 33540536 PMCID: PMC7912908 DOI: 10.3390/life11020112] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/25/2021] [Accepted: 01/28/2021] [Indexed: 12/16/2022] Open
Abstract
Immune dysfunction has long been reported by medical professionals regarding astronauts suffering from opportunistic infections both during their time in space and a short period afterwards once back on Earth. Various species of prokaryotes onboard these space missions or cultured in a microgravity analogue exhibit increased virulence, enhanced formation of biofilms, and in some cases develop specific resistance for specific antibiotics. This poses a substantial health hazard to the astronauts confined in constant proximity to any present bacterial pathogens on long space missions with a finite number of resources including antibiotics. Furthermore, some bacteria cultured in microgravity develop phenotypes not seen in Earth gravity conditions, providing novel insights into bacterial evolution and avenues for research. Immune dysfunction caused by exposure to microgravity may increase the chance of bacterial infection. Immune cell stimulation, toll-like receptors and pathogen-associated molecular patterns can all be altered in microgravity and affect immunological crosstalk and response. Production of interleukins and other cytokines can also be altered leading to immune dysfunction when responding to bacterial infection. Stem cell differentiation and immune cell activation and proliferation can also be impaired and altered by the microgravity environment once more adding to immune dysfunction in microgravity. This review elaborates on and contextualises these findings relating to how bacteria can adapt to microgravity and how the immune system subsequently responds to infection.
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Affiliation(s)
- Macauley J. Green
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK; (M.J.G.); (J.W.A.)
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; (P.W.); (A.M.G.)
| | - Jonathan W. Aylott
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK; (M.J.G.); (J.W.A.)
| | - Paul Williams
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; (P.W.); (A.M.G.)
| | - Amir M. Ghaemmaghami
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; (P.W.); (A.M.G.)
| | - Philip M. Williams
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK; (M.J.G.); (J.W.A.)
- Correspondence:
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18
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Exploration of space to achieve scientific breakthroughs. Biotechnol Adv 2020; 43:107572. [PMID: 32540473 DOI: 10.1016/j.biotechadv.2020.107572] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/05/2020] [Accepted: 05/29/2020] [Indexed: 12/13/2022]
Abstract
Living organisms adapt to changing environments using their amazing flexibility to remodel themselves by a process called evolution. Environmental stress causes selective pressure and is associated with genetic and phenotypic shifts for better modifications, maintenance, and functioning of organismal systems. The natural evolution process can be used in complement to rational strain engineering for the development of desired traits or phenotypes as well as for the production of novel biomaterials through the imposition of one or more selective pressures. Space provides a unique environment of stressors (e.g., weightlessness and high radiation) that organisms have never experienced on Earth. Cells in the outer space reorganize and develop or activate a range of molecular responses that lead to changes in cellular properties. Exposure of cells to the outer space will lead to the development of novel variants more efficiently than on Earth. For instance, natural crop varieties can be generated with higher nutrition value, yield, and improved features, such as resistance against high and low temperatures, salt stress, and microbial and pest attacks. The review summarizes the literature on the parameters of outer space that affect the growth and behavior of cells and organisms as well as complex colloidal systems. We illustrate an understanding of gravity-related basic biological mechanisms and enlighten the possibility to explore the outer space environment for application-oriented aspects. This will stimulate biological research in the pursuit of innovative approaches for the future of agriculture and health on Earth.
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19
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Milojevic T, Weckwerth W. Molecular Mechanisms of Microbial Survivability in Outer Space: A Systems Biology Approach. Front Microbiol 2020; 11:923. [PMID: 32499769 PMCID: PMC7242639 DOI: 10.3389/fmicb.2020.00923] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/20/2020] [Indexed: 01/08/2023] Open
Abstract
Since the dawn of space exploration, the survivability of terrestrial life in outer space conditions has attracted enormous attention. Space technology has enabled the development of advanced space exposure facilities to investigate in situ responses of microbial life to the stress conditions of space during interplanetary transfer. Significant progress has been made toward the understanding of the effects of space environmental factors, e.g., microgravity, vacuum and radiation, on microorganisms exposed to real and simulated space conditions. Of extreme importance is not only knowledge of survival potential of space-exposed microorganisms, but also the determination of mechanisms of survival and adaptation of predominant species to the extreme space environment, i.e., revealing the molecular machinery, which elicit microbial survivability and adaptation. Advanced technologies in -omics research have permitted genome-scale studies of molecular alterations of space-exposed microorganisms. A variety of reports show that microorganisms grown in the space environment exhibited global alterations in metabolic functions and gene expression at the transcriptional and translational levels. Proteomic, metabolomic and especially metabolic modeling approaches as essential instruments of space microbiology, synthetic biology and metabolic engineering are rather underrepresented. Here we summarized the molecular space-induced alterations of exposed microorganisms in terms of understanding the molecular mechanisms of microbial survival and adaptation to drastic outer space environment.
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Affiliation(s)
- Tetyana Milojevic
- Extremophiles/Space Biochemistry Group, Department of Biophysical Chemistry, University of Vienna, Vienna, Austria
| | - Wolfram Weckwerth
- Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
- Vienna Metabolomics Center, University of Vienna, Vienna, Austria
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20
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Molecular response of Deinococcus radiodurans to simulated microgravity explored by proteometabolomic approach. Sci Rep 2019; 9:18462. [PMID: 31804539 PMCID: PMC6895123 DOI: 10.1038/s41598-019-54742-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/19/2019] [Indexed: 12/21/2022] Open
Abstract
Regarding future space exploration missions and long-term exposure experiments, a detailed investigation of all factors present in the outer space environment and their effects on organisms of all life kingdoms is advantageous. Influenced by the multiple factors of outer space, the extremophilic bacterium Deinococcus radiodurans has been long-termly exposed outside the International Space Station in frames of the Tanpopo orbital mission. The study presented here aims to elucidate molecular key components in D. radiodurans, which are responsible for recognition and adaptation to simulated microgravity. D. radiodurans cultures were grown for two days on plates in a fast-rotating 2-D clinostat to minimize sedimentation, thus simulating reduced gravity conditions. Subsequently, metabolites and proteins were extracted and measured with mass spectrometry-based techniques. Our results emphasize the importance of certain signal transducer proteins, which showed higher abundances in cells grown under reduced gravity. These proteins activate a cellular signal cascade, which leads to differences in gene expressions. Proteins involved in stress response, repair mechanisms and proteins connected to the extracellular milieu and the cell envelope showed an increased abundance under simulated microgravity. Focusing on the expression of these proteins might present a strategy of cells to adapt to microgravity conditions.
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21
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Clinostat Rotation Affects Metabolite Transportation and Increases Organic Acid Production by Aspergillus carbonarius, as Revealed by Differential Metabolomic Analysis. Appl Environ Microbiol 2019; 85:AEM.01023-19. [PMID: 31300399 DOI: 10.1128/aem.01023-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 06/27/2019] [Indexed: 02/06/2023] Open
Abstract
Contamination by fungi may pose a threat to the long-term operation of the International Space Station because fungi produce organic acids that corrode equipment and mycotoxins that harm human health. Microgravity is an unavoidable and special condition in the space station. However, the influence of microgravity on fungal metabolism has not been well studied. Clinostat rotation is widely used to simulate the microgravity condition in studies carried out on Earth. Here, we used metabolomics differential analysis to study the influence of clinostat rotation on the accumulation of organic acids and related biosynthetic pathways in ochratoxin A (OTA)-producing Aspergillus carbonarius As a result, clinostat rotation did not affect fungal cell growth or colony appearance but significantly increased the accumulation of organic acids, particularly isocitric acid, citric acid, and oxalic acid, and OTA both inside cells and in the medium, as well as resulted in a much higher level of accumulation of some products inside than outside cells, indicating that the transport of these metabolites from the cell to the medium was inhibited. This finding corresponded to the change in the fatty acid composition of cell membranes and the reduced thickness of the cell walls and cell membranes. Amino acid and energy metabolic pathways, particularly the tricarboxylic acid cycle, were influenced the most during clinostat rotation compared to the effects of normal gravity on these pathways.IMPORTANCE Fungi are ubiquitous in nature and have the ability to corrode various materials by producing metabolites. Research on how the space station environment, especially microgravity, affects fungal metabolism is helpful to understand the role of fungi in the space station. This work provides insights into the mechanisms involved in the metabolism of the corrosive fungus Aspergillus carbonarius under simulated microgravity conditions. Our findings have significance not only for preventing material corrosion but also for ensuring food safety, especially in the space environment.
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22
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Zhang B, Bai P, Zhao X, Yu Y, Zhang X, Li D, Liu C. Increased growth rate and amikacin resistance of Salmonella enteritidis after one-month spaceflight on China's Shenzhou-11 spacecraft. Microbiologyopen 2019; 8:e00833. [PMID: 30912318 PMCID: PMC6741137 DOI: 10.1002/mbo3.833] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/12/2019] [Accepted: 02/14/2019] [Indexed: 12/30/2022] Open
Abstract
China launched the Tiangong-2 space laboratory in 2016 and will eventually build a basic space station by the early 2020s. These spaceflight missions require astronauts to stay on the space station for more than 6 months, and they inevitably carry microbes into the space environment. It is known that the space environment affects microbial behavior, including growth rate, biofilm formation, virulence, drug resistance, and metabolism. However, the mechanisms of these alternations have not been fully elucidated. Therefore, it is beneficial to monitor microorganisms for preventing infections among astronauts in a space environment. Salmonella enteritidis is a Gram-negative bacterial pathogen that commonly causes acute gastroenteritis in humans. In this study, to better understand the effects of the space environment on S. enteritidis, a S. enteritidis strain was taken into space by the Shenzhou-11 spacecraft from 17 October 2016 to 18 November 2016, and a ground simulation with similar temperature conditions was simultaneously performed as a control. It was found that the flight strain displayed an increased growth rate, enhanced amikacin resistance, and some metabolism alterations compared with the ground strain. Enrichment analysis of proteome revealed that the increased growth rate might be associated with differentially expressed proteins involved in transmembrane transport and energy production and conversion assembly. A combined transcriptome and proteome analysis showed that the amikacin resistance was due to the downregulation of the oppA gene and oligopeptide transporter protein OppA. In conclusion, this study is the first systematic analysis of the phenotypic, genomic, transcriptomic, and proteomic variations in S. enteritidis during spaceflight and will provide beneficial insights for future studies on space microbiology.
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Affiliation(s)
- Bin Zhang
- Nankai University School of Medicine, Tianjin, China.,Respiratory Diseases Department, The Second Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Po Bai
- Respiratory Diseases Department, The Second Medical Center of Chinese PLA General Hospital, Beijing, China.,Respiratory Diseases Department, PLA Rocket Force Characteristic Medical Center, Beijing, China
| | - Xian Zhao
- Respiratory Diseases Department, The Second Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Yi Yu
- Respiratory Diseases Department, The Second Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Xuelin Zhang
- Respiratory Diseases Department, The Second Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Diangeng Li
- Respiratory Diseases Department, The Second Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Changting Liu
- Nankai University School of Medicine, Tianjin, China.,Respiratory Diseases Department, The Second Medical Center of Chinese PLA General Hospital, Beijing, China
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23
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Evaluation of Acquired Antibiotic Resistance in Escherichia coli Exposed to Long-Term Low-Shear Modeled Microgravity and Background Antibiotic Exposure. mBio 2019; 10:mBio.02637-18. [PMID: 30647159 PMCID: PMC6336426 DOI: 10.1128/mbio.02637-18] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Stress factors experienced during space include microgravity, sleep deprivation, radiation, isolation, and microbial contamination, all of which can promote immune suppression (1, 2). Under these conditions, the risk of infection from opportunistic pathogens increases significantly, particularly during long-term missions (3). If infection occurs, it is important that the infectious agent should not be antibiotic resistant. Minimizing the occurrence of antibiotic resistance is, therefore, highly desirable. To facilitate this, it is important to better understand the long-term response of bacteria to the microgravity environment. This study demonstrated that the use of antibiotics as a preventive measure could be counterproductive and would likely result in persistent resistance to that antibiotic. In addition, unintended resistance to other antimicrobials might also occur as well as permanent genome changes that might have other unanticipated and undesirable consequences. The long-term response of microbial communities to the microgravity environment of space is not yet fully understood. Of special interest is the possibility that members of these communities may acquire antibiotic resistance. In this study, Escherichia coli cells were grown under low-shear modeled microgravity (LSMMG) conditions for over 1,000 generations (1000G) using chloramphenicol treatment between cycles to prevent contamination. The results were compared with data from an earlier control study done under identical conditions using steam sterilization between cycles rather than chloramphenicol. The sensitivity of the final 1000G-adapted strain to a variety of antibiotics was determined using Vitek analysis. In addition to resistance to chloramphenicol, the adapted strain acquired resistance to cefalotin, cefuroxime, cefuroxime axetil, cefoxitin, and tetracycline. In fact, the resistance to chloramphenicol and cefalotin persisted for over 110 generations despite the removal of both LSMMG conditions and trace antibiotic exposure. Genome sequencing of the adapted strain revealed 22 major changes, including 3 transposon-mediated rearrangements (TMRs). Two TMRs disrupted coding genes (involved in bacterial adhesion), while the third resulted in the deletion of an entire segment (14,314 bp) of the genome, which includes 14 genes involved with motility and chemotaxis. These results are in stark contrast with data from our earlier control study in which cells grown under the identical conditions without antibiotic exposure never acquired antibiotic resistance. Overall, LSMMG does not appear to alter the antibiotic stress resistance seen in microbial ecosystems not exposed to microgravity.
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Transcriptional profiling of the mutualistic bacterium Vibrio fischeri and an hfq mutant under modeled microgravity. NPJ Microgravity 2018; 4:25. [PMID: 30588486 PMCID: PMC6299092 DOI: 10.1038/s41526-018-0060-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 11/05/2018] [Indexed: 02/06/2023] Open
Abstract
For long-duration space missions, it is critical to maintain health-associated homeostasis between astronauts and their microbiome. To achieve this goal it is important to more fully understand the host–symbiont relationship under the physiological stress conditions of spaceflight. To address this issue we examined the impact of a spaceflight analog, low-shear-modeled microgravity (LSMMG), on the transcriptome of the mutualistic bacterium Vibrio fischeri. Cultures of V. fischeri and a mutant defective in the global regulator Hfq (∆hfq) were exposed to either LSMMG or gravity conditions for 12 h (exponential growth) and 24 h (stationary phase growth). Comparative transcriptomic analysis revealed few to no significant differentially expressed genes between gravity and the LSMMG conditions in the wild type or mutant V. fischeri at exponential or stationary phase. There was, however, a pronounced change in transcriptomic profiles during the transition between exponential and stationary phase growth in both V. fischeri cultures including an overall decrease in gene expression associated with translational activity and an increase in stress response. There were also several upregulated stress genes specific to the LSMMG condition during the transition to stationary phase growth. The ∆hfq mutants exhibited a distinctive transcriptome profile with a significant increase in transcripts associated with flagellar synthesis and transcriptional regulators under LSMMG conditions compared to gravity controls. These results indicate the loss of Hfq significantly influences gene expression under LSMMG conditions in a bacterial symbiont. Together, these results improve our understanding of the mechanisms by which microgravity alters the physiology of beneficial host-associated microbes.
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25
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Modeling Host-Pathogen Interactions in the Context of the Microenvironment: Three-Dimensional Cell Culture Comes of Age. Infect Immun 2018; 86:IAI.00282-18. [PMID: 30181350 DOI: 10.1128/iai.00282-18] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Tissues and organs provide the structural and biochemical landscapes upon which microbial pathogens and commensals function to regulate health and disease. While flat two-dimensional (2-D) monolayers composed of a single cell type have provided important insight into understanding host-pathogen interactions and infectious disease mechanisms, these reductionist models lack many essential features present in the native host microenvironment that are known to regulate infection, including three-dimensional (3-D) architecture, multicellular complexity, commensal microbiota, gas exchange and nutrient gradients, and physiologically relevant biomechanical forces (e.g., fluid shear, stretch, compression). A major challenge in tissue engineering for infectious disease research is recreating this dynamic 3-D microenvironment (biological, chemical, and physical/mechanical) to more accurately model the initiation and progression of host-pathogen interactions in the laboratory. Here we review selected 3-D models of human intestinal mucosa, which represent a major portal of entry for infectious pathogens and an important niche for commensal microbiota. We highlight seminal studies that have used these models to interrogate host-pathogen interactions and infectious disease mechanisms, and we present this literature in the appropriate historical context. Models discussed include 3-D organotypic cultures engineered in the rotating wall vessel (RWV) bioreactor, extracellular matrix (ECM)-embedded/organoid models, and organ-on-a-chip (OAC) models. Collectively, these technologies provide a more physiologically relevant and predictive framework for investigating infectious disease mechanisms and antimicrobial therapies at the intersection of the host, microbe, and their local microenvironments.
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26
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Senatore G, Mastroleo F, Leys N, Mauriello G. Effect of microgravity & space radiation on microbes. Future Microbiol 2018; 13:831-847. [PMID: 29745771 DOI: 10.2217/fmb-2017-0251] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
One of the new challenges facing humanity is to reach increasingly further distant space targets. It is therefore of upmost importance to understand the behavior of microorganisms that will unavoidably reach the space environment together with the human body and equipment. Indeed, microorganisms could activate their stress defense mechanisms, modifying properties related to human pathogenesis. The host-microbe interactions, in fact, could be substantially affected under spaceflight conditions and the study of microorganisms' growth and activity is necessary for predicting these behaviors and assessing precautionary measures during spaceflight. This review gives an overview of the effects of microgravity and space radiation on microorganisms both in real and simulated conditions.
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Affiliation(s)
- Giuliana Senatore
- Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici, Naples, Italy
| | - Felice Mastroleo
- Microbiology Unit, Belgian Nuclear Research Centre (SCK•CEN), 2400 Mol, Belgium
| | - Natalie Leys
- Microbiology Unit, Belgian Nuclear Research Centre (SCK•CEN), 2400 Mol, Belgium
| | - Gianluigi Mauriello
- Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici, Naples, Italy
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The adaptation of Escherichia coli cells grown in simulated microgravity for an extended period is both phenotypic and genomic. NPJ Microgravity 2017. [PMID: 28649637 PMCID: PMC5460176 DOI: 10.1038/s41526-017-0020-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Microorganisms impact spaceflight in a variety of ways. They play a positive role in biological systems, such as waste water treatment but can be problematic through buildups of biofilms that can affect advanced life support. Of special concern is the possibility that during extended missions, the microgravity environment will provide positive selection for undesirable genomic changes. Such changes could affect microbial antibiotic sensitivity and possibly pathogenicity. To evaluate this possibility, Escherichia coli (lac plus) cells were grown for over 1000 generations on Luria Broth medium under low-shear modeled microgravity conditions in a high aspect rotating vessel. This is the first study of its kind to grow bacteria for multiple generations over an extended period under low-shear modeled microgravity. Comparisons were made to a non-adaptive control strain using growth competitions. After 1000 generations, the final low-shear modeled microgravity-adapted strain readily outcompeted the unadapted lac minus strain. A portion of this advantage was maintained when the low-shear modeled microgravity strain was first grown in a shake flask environment for 10, 20, or 30 generations of growth. Genomic sequencing of the 1000 generation strain revealed 16 mutations. Of the five changes affecting codons, none were neutral. It is not clear how significant these mutations are as individual changes or as a group. It is concluded that part of the long-term adaptation to low-shear modeled microgravity is likely genomic. The strain was monitored for acquisition of antibiotic resistance by VITEK analysis throughout the adaptation period. Despite the evidence of genomic adaptation, resistance to a variety of antibiotics was never observed.
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