1
|
Muratov E, Rosenbaum FP, Fuchs FM, Ulrich NJ, Awakowicz P, Setlow P, Moeller R. Multifactorial resistance of Bacillus subtilis spores to low-pressure plasma sterilization. Appl Environ Microbiol 2024; 90:e0132923. [PMID: 38112445 PMCID: PMC10807416 DOI: 10.1128/aem.01329-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/05/2023] [Indexed: 12/21/2023] Open
Abstract
Common sterilization techniques for labile and sensitive materials have far-reaching applications in medical, pharmaceutical, and industrial fields. Heat inactivation, chemical treatment, and radiation are established methods to inactivate microorganisms, but pose a threat to humans and the environment and can damage susceptible materials or products. Recent studies have demonstrated that cold low-pressure plasma (LPP) treatment is an efficient alternative to common sterilization methods, as LPP's levels of radicals, ions, (V)UV-radiation, and exposure to an electromagnetic field can be modulated using different process gases, such as oxygen, nitrogen, argon, or synthetic (ambient) air. To further investigate the effects of LPP, spores of the Gram-positive model organism Bacillus subtilis were tested for their LPP susceptibility including wild-type spores and isogenic spores lacking DNA-repair mechanisms such as non-homologous end-joining (NHEJ) or abasic endonucleases, and protective proteins like α/β-type small acid-soluble spore proteins (SASP), coat proteins, and catalase. These studies aimed to learn how spores resist LPP damage by examining the roles of key spore proteins and DNA-repair mechanisms. As expected, LPP treatment decreased spore survival, and survival after potential DNA damage generated by LPP involved efficient DNA repair following spore germination, spore DNA protection by α/β-type SASP, and catalase breakdown of hydrogen peroxide that can generate oxygen radicals. Depending on the LPP composition and treatment time, LPP treatment offers another method to efficiently inactivate spore-forming bacteria.IMPORTANCESurface-associated contamination by endospore-forming bacteria poses a major challenge in sterilization, since the omnipresence of these highly resistant spores throughout nature makes contamination unavoidable, especially in unprocessed foods. Common bactericidal agents such as heat, UV and γ radiation, and toxic chemicals such as strong oxidizers: (i) are often not sufficient to completely inactivate spores; (ii) can pose risks to the applicant; or (iii) can cause unintended damage to the materials to be sterilized. Cold low-pressure plasma (LPP) has been proposed as an additional method for spore eradication. However, efficient use of LPP in decontamination requires understanding of spores' mechanisms of resistance to and protection against LPP.
Collapse
Affiliation(s)
- Erika Muratov
- Radiation Biology Department, Aerospace Microbiology, Institute of Aerospace Medicine, German Aerospace Center (DLR e.V.), Cologne, Germany
| | - Florian P. Rosenbaum
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
| | - Felix M. Fuchs
- Applied Electrodynamics and Plasma Technology, Biomedical Applications of Plasma Technology, Ruhr University Bochum, Bochum, Germany
| | - Nikea J. Ulrich
- Division of Biological Sciences, University of Montana, Missoula, Montana, USA
| | - Peter Awakowicz
- Applied Electrodynamics and Plasma Technology, Biomedical Applications of Plasma Technology, Ruhr University Bochum, Bochum, Germany
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Ralf Moeller
- Radiation Biology Department, Aerospace Microbiology, Institute of Aerospace Medicine, German Aerospace Center (DLR e.V.), Cologne, Germany
| |
Collapse
|
2
|
Fuchs FM, Bibinov N, Blanco EV, Pfaender S, Theiß S, Wolter H, Awakowicz P. Characterization of a robot-assisted UV-C disinfection for the inactivation of surface-associated microorganisms and viruses. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2022; 11:100123. [PMID: 36034107 PMCID: PMC9392416 DOI: 10.1016/j.jpap.2022.100123] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/07/2022] [Accepted: 04/30/2022] [Indexed: 11/26/2022] Open
Abstract
Microorganisms pose a serious threat for us humans, which is exemplified by the recent emergence of pathogens such as SARS-CoV-2 or the increasing number of multi-resistant pathogens such as MRSA. To control surface microorganisms and viruses, we investigated the disinfection properties of an AI-controlled robot, HERO21, equipped with eight 130-W low pressure UV-C mercury vapor discharge lamps emitting at a wavelength of 254 nm, which is strongly absorbed by DNA and RNA, thus inactivating illuminated microorganisms. Emissivity and spatial irradiance distribution of a single UV-C lamp unit was determined using a calibrated spectrometer and numerical simulation, respectively. The disinfection efficiency of single lamps is determined by microbiological tests using B. subtilis spores, which are known to be UV-C resistant. The required time for D99 disinfection and the corresponding UV-C irradiance dose amount to 60 s and 37.3 mJ•cm−2 at a distance of 1 m to the Hg-lamp, respectively. Spatially resolved irradiance produced by a disinfection unit consisting of eight lamps is calculated using results of one UV-C lamp characterization. This calculation shows that the UV-C robot HERO21 equipped with the mentioned UV-C unit causes an irradiance at λ=254 nm of 2.67 mJ•cm−2•s−1 at 1 m and 0.29 mJ•cm−2•s−1 at 3 m distances. These values result in D99 disinfection times of 14 s and 129 s for B. subtilis spores, respectively. Similarly, human coronavirus 229E, structurally very similar to SARS-CoV-2, could be efficiently inactivated by 3–5 orders of magnitude within 10 - 30 s exposure time or doses of 2 - 6 mJ•cm−2, respectively. In conclusion, with the development of the HERO21 disinfection robot, we were able to determine the inactivation efficiency of bacteria and viruses on surfaces under laboratory conditions.
Collapse
|
3
|
Cockell CS, Santomartino R, Finster K, Waajen AC, Nicholson N, Loudon CM, Eades LJ, Moeller R, Rettberg P, Fuchs FM, Van Houdt R, Leys N, Coninx I, Hatton J, Parmitano L, Krause J, Koehler A, Caplin N, Zuijderduijn L, Mariani A, Pellari S, Carubia F, Luciani G, Balsamo M, Zolesi V, Ochoa J, Sen P, Watt JAJ, Doswald-Winkler J, Herová M, Rattenbacher B, Wadsworth J, Everroad RC, Demets R. Microbially-Enhanced Vanadium Mining and Bioremediation Under Micro- and Mars Gravity on the International Space Station. Front Microbiol 2021; 12:641387. [PMID: 33868198 PMCID: PMC8047202 DOI: 10.3389/fmicb.2021.641387] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/04/2021] [Indexed: 11/30/2022] Open
Abstract
As humans explore and settle in space, they will need to mine elements to support industries such as manufacturing and construction. In preparation for the establishment of permanent human settlements across the Solar System, we conducted the ESA BioRock experiment on board the International Space Station to investigate whether biological mining could be accomplished under extraterrestrial gravity conditions. We tested the hypothesis that the gravity (g) level influenced the efficacy with which biomining could be achieved from basalt, an abundant material on the Moon and Mars, by quantifying bioleaching by three different microorganisms under microgravity, simulated Mars and Earth gravitational conditions. One element of interest in mining is vanadium (V), which is added to steel to fabricate high strength, corrosion-resistant structural materials for buildings, transportation, tools and other applications. The results showed that Sphingomonas desiccabilis and Bacillus subtilis enhanced the leaching of vanadium under the three gravity conditions compared to sterile controls by 184.92 to 283.22%, respectively. Gravity did not have a significant effect on mean leaching, thus showing the potential for biomining on Solar System objects with diverse gravitational conditions. Our results demonstrate the potential to use microorganisms to conduct elemental mining and other bioindustrial processes in space locations with non-1 × g gravity. These same principles apply to extraterrestrial bioremediation and elemental recycling beyond Earth.
Collapse
Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Rosa Santomartino
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Kai Finster
- Department of Biology - Microbiology, Aarhus University, Aarhus, Denmark
| | - Annemiek C Waajen
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Natasha Nicholson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Claire-Marie Loudon
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Lorna J Eades
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - Ralf Moeller
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
| | - Petra Rettberg
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
| | - Felix M Fuchs
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany.,Institute of Electrical Engineering and Plasma Technology, Faculty of Electrical Engineering and Information Sciences, Ruhr University Bochum, Bochum, Germany
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Natalie Leys
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Ilse Coninx
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | - Jon Ochoa
- ESTEC, Noordwijk, Netherlands.,Space Application Services NV/SA, Noordwijk, Netherlands
| | - Pia Sen
- Earth and Environmental Sciences Department, Rutgers University, Newark, NJ, United States
| | - James A J Watt
- School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jeannine Doswald-Winkler
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Hergiswil, Switzerland
| | - Magdalena Herová
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Hergiswil, Switzerland
| | - Bernd Rattenbacher
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Hergiswil, Switzerland
| | - Jennifer Wadsworth
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States
| | - R Craig Everroad
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States
| | | |
Collapse
|
4
|
Cockell CS, Santomartino R, Finster K, Waajen AC, Eades LJ, Moeller R, Rettberg P, Fuchs FM, Van Houdt R, Leys N, Coninx I, Hatton J, Parmitano L, Krause J, Koehler A, Caplin N, Zuijderduijn L, Mariani A, Pellari SS, Carubia F, Luciani G, Balsamo M, Zolesi V, Nicholson N, Loudon CM, Doswald-Winkler J, Herová M, Rattenbacher B, Wadsworth J, Craig Everroad R, Demets R. Space station biomining experiment demonstrates rare earth element extraction in microgravity and Mars gravity. Nat Commun 2020; 11:5523. [PMID: 33173035 PMCID: PMC7656455 DOI: 10.1038/s41467-020-19276-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 10/07/2020] [Indexed: 11/24/2022] Open
Abstract
Microorganisms are employed to mine economically important elements from rocks, including the rare earth elements (REEs), used in electronic industries and alloy production. We carried out a mining experiment on the International Space Station to test hypotheses on the bioleaching of REEs from basaltic rock in microgravity and simulated Mars and Earth gravities using three microorganisms and a purposely designed biomining reactor. Sphingomonas desiccabilis enhanced mean leached concentrations of REEs compared to non-biological controls in all gravity conditions. No significant difference in final yields was observed between gravity conditions, showing the efficacy of the process under different gravity regimens. Bacillus subtilis exhibited a reduction in bioleaching efficacy and Cupriavidus metallidurans showed no difference compared to non-biological controls, showing the microbial specificity of the process, as on Earth. These data demonstrate the potential for space biomining and the principles of a reactor to advance human industry and mining beyond Earth. Rare earth elements are used in electronics, but increase in demand could lead to low supply. Here the authors conduct experiments on the International Space Station and show microbes can extract rare elements from rocks at low gravity, a finding that could extend mining potential to other planets.
Collapse
Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
| | - Rosa Santomartino
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Kai Finster
- Department of Bioscience-Microbiology, Ny Munkegade 116, Building 1540, 129, 8000, Aarhus C, Denmark
| | - Annemiek C Waajen
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Lorna J Eades
- School of Chemistry, University of Edinburgh, Edinburgh, UK
| | - Ralf Moeller
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Linder Hoehe, Köln, Germany
| | - Petra Rettberg
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Linder Hoehe, Köln, Germany
| | - Felix M Fuchs
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Linder Hoehe, Köln, Germany.,Institute of Electrical Engineering and Plasma Technology, Faculty of Electrical Engineering and Information Sciences, Ruhr University Bochum, Bochum, Germany
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Natalie Leys
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Ilse Coninx
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Jason Hatton
- ESTEC, Keplerlaan 1, 2201 AZ, Noordwijk, Netherlands
| | | | - Jutta Krause
- ESTEC, Keplerlaan 1, 2201 AZ, Noordwijk, Netherlands
| | | | - Nicol Caplin
- ESTEC, Keplerlaan 1, 2201 AZ, Noordwijk, Netherlands
| | | | | | | | - Fabrizio Carubia
- Kayser Italia S.r.l., Via di Popogna, 501, 57128, Livorno, Italy
| | - Giacomo Luciani
- Kayser Italia S.r.l., Via di Popogna, 501, 57128, Livorno, Italy
| | - Michele Balsamo
- Kayser Italia S.r.l., Via di Popogna, 501, 57128, Livorno, Italy
| | - Valfredo Zolesi
- Kayser Italia S.r.l., Via di Popogna, 501, 57128, Livorno, Italy
| | - Natasha Nicholson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Claire-Marie Loudon
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Jeannine Doswald-Winkler
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Obermattweg 9, 6052, Hergiswil, Switzerland
| | - Magdalena Herová
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Obermattweg 9, 6052, Hergiswil, Switzerland
| | - Bernd Rattenbacher
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Obermattweg 9, 6052, Hergiswil, Switzerland
| | | | - R Craig Everroad
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, USA
| | - René Demets
- ESTEC, Keplerlaan 1, 2201 AZ, Noordwijk, Netherlands
| |
Collapse
|
5
|
Santomartino R, Waajen AC, de Wit W, Nicholson N, Parmitano L, Loudon CM, Moeller R, Rettberg P, Fuchs FM, Van Houdt R, Finster K, Coninx I, Krause J, Koehler A, Caplin N, Zuijderduijn L, Zolesi V, Balsamo M, Mariani A, Pellari SS, Carubia F, Luciani G, Leys N, Doswald-Winkler J, Herová M, Wadsworth J, Everroad RC, Rattenbacher B, Demets R, Cockell CS. No Effect of Microgravity and Simulated Mars Gravity on Final Bacterial Cell Concentrations on the International Space Station: Applications to Space Bioproduction. Front Microbiol 2020; 11:579156. [PMID: 33154740 PMCID: PMC7591705 DOI: 10.3389/fmicb.2020.579156] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/09/2020] [Indexed: 12/24/2022] Open
Abstract
Microorganisms perform countless tasks on Earth and they are expected to be essential for human space exploration. Despite the interest in the responses of bacteria to space conditions, the findings on the effects of microgravity have been contradictory, while the effects of Martian gravity are nearly unknown. We performed the ESA BioRock experiment on the International Space Station to study microbe-mineral interactions in microgravity, simulated Mars gravity and simulated Earth gravity, as well as in ground gravity controls, with three bacterial species: Sphingomonas desiccabilis, Bacillus subtilis, and Cupriavidus metallidurans. To our knowledge, this was the first experiment to study simulated Martian gravity on bacteria using a space platform. Here, we tested the hypothesis that different gravity regimens can influence the final cell concentrations achieved after a multi-week period in space. Despite the different sedimentation rates predicted, we found no significant differences in final cell counts and optical densities between the three gravity regimens on the ISS. This suggests that possible gravity-related effects on bacterial growth were overcome by the end of the experiment. The results indicate that microbial-supported bioproduction and life support systems can be effectively performed in space (e.g., Mars), as on Earth.
Collapse
Affiliation(s)
- Rosa Santomartino
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Annemiek C Waajen
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Wessel de Wit
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Natasha Nicholson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Luca Parmitano
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Claire-Marie Loudon
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Ralf Moeller
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne (Köln), Germany
| | - Petra Rettberg
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne (Köln), Germany
| | - Felix M Fuchs
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne (Köln), Germany
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Kai Finster
- Department of Biology - Microbiology, Aarhus University, Aarhus C, Denmark
| | - Ilse Coninx
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Jutta Krause
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Andrea Koehler
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Nicol Caplin
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Lobke Zuijderduijn
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | | | | | | | | | | | | | - Natalie Leys
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | | | - Magdalena Herová
- BIOTESC, Hochschule Luzern Technik und Architektur, Hergiswil, Switzerland
| | - Jennifer Wadsworth
- Exobiology Branch, NASA Ames Research Center, Moffet Field, CA, United States
| | - R Craig Everroad
- Exobiology Branch, NASA Ames Research Center, Moffet Field, CA, United States
| | - Bernd Rattenbacher
- BIOTESC, Hochschule Luzern Technik und Architektur, Hergiswil, Switzerland
| | - René Demets
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
6
|
Garschagen LS, Mancinelli RL, Moeller R. Introducing Vibrio natriegens as a Microbial Model Organism for Microgravity Research. ASTROBIOLOGY 2019; 19:1211-1220. [PMID: 31486680 DOI: 10.1089/ast.2018.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Microbial contamination of human-tended spacecraft is unavoidable, making the study of microbial growth under space conditions essential for the preservation of astronauts' health and equipment integrity. Previous studies suggested that spaceflight conditions, such as microgravity, cause a range of physiological microbial alterations including increased growth yields and decreased antibiotic susceptibility. Because of its fast generation time, Vibrio natriegens could be used as a model organism for a variety of studies where generation time is a critical factor. In this study, V. natriegens was used as a tool to study growth characteristics by determining the viable cell number and antibiotic susceptibility under simulated microgravity using a 2-D clinostat (60 rpm) to establish a test system that resolves changes in microbial growth on a solid surface (agar) under microgravity. The data show that V. natriegens biomass increases significantly after 24 h at 37°C under simulated microgravity. The final cell population after cultivation under simulated microgravity was 60-fold greater than when cultivated under normal terrestrial gravity (1 × g). No change in susceptibility to the antibiotic rifampicin after cultivation under simulated microgravity or normal gravity was detected. These data show that V. natriegens is a new and innovative model organism for microbial microgravity research.
Collapse
Affiliation(s)
- Laura S Garschagen
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne (Köln), Germany
- University of Bonn, Institute for Microbiology and Biotechnology (IfMB), Bonn, Germany
| | - Rocco L Mancinelli
- NASA Ames Research Center, Bay Area Environmental Research Institute, Moffett Field, California, USA
| | - Ralf Moeller
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne (Köln), Germany
| |
Collapse
|
7
|
Fuchs FM, Holland G, Moeller R, Laue M. Directed freeze-fracturing of Bacillus subtilis biofilms for conventional scanning electron microscopy. J Microbiol Methods 2018; 152:165-172. [PMID: 30125587 DOI: 10.1016/j.mimet.2018.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/13/2018] [Accepted: 08/14/2018] [Indexed: 10/28/2022]
Abstract
Biofilms have been intensively investigated over the past decades. Bacillus subtilis is able to form highly structured colony biofilms, and as one of the most studied Gram-positive model organisms, has helped to decipher the complex genetic regulation of biofilms. Several methods have been developed to analyze the architecture of biofilms. In this paper, we describe a method which allows the analysis of the internal structures of biofilms by scanning electron microscopy (SEM). The method uses a modified freeze-fracturing of chemically fixed biofilm to generate defined, well-preserved fractures at millimeter-scale which allows to analyze systematically the internal biofilm structure from macro- to nano-scale.
Collapse
Affiliation(s)
- Felix M Fuchs
- German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany.
| | - Gudrun Holland
- Robert Koch Institute, Advanced Light and Electron Microscopy (ZBS 4), Berlin, Germany
| | - Ralf Moeller
- German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Michael Laue
- Robert Koch Institute, Advanced Light and Electron Microscopy (ZBS 4), Berlin, Germany
| |
Collapse
|
8
|
Xiong R, Xiao K, Yi P, Hu Y, Dong C, Wu J, Li X. The influence of Bacillus subtilis on tin-coated copper in an aqueous environment. RSC Adv 2018; 8:4671-4679. [PMID: 35539564 PMCID: PMC9078041 DOI: 10.1039/c7ra07864a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 01/10/2018] [Indexed: 12/01/2022] Open
Abstract
The influence of Bacillus subtilis (BS) on tin-coated copper in an aqueous environment was investigated by exposing the sample to a culture medium inoculated with BS. Scanning electron microscopy, electrochemical measurements and chemical analyses were performed to study the corrosion mechanism. The experimental results show that BS can adhere and gather on the surface of the sample, resulting in oxygen consumption at the place where the bacteria are densely attached. Increases in the Rct values after the initial immersion showed that corrosion was inhibited, while decreases in the Rct values after the later immersion showed that corrosion was accelerated. Our results suggest that differences in oxygen concentration due to activity of BS are the main reason for corrosion of tin-coated copper. The effect of Bacillus subtilis (BS) on the corrosion behaviour of tin-coated copper was investigated by exposing the sample to a culture medium inoculated with BS.![]()
Collapse
Affiliation(s)
- Ruilin Xiong
- Corrosion and Protection Center, University of Science and Technology Beijing Beijing 100083 P. R. China
| | - Kui Xiao
- Corrosion and Protection Center, University of Science and Technology Beijing Beijing 100083 P. R. China
| | - Pan Yi
- Corrosion and Protection Center, University of Science and Technology Beijing Beijing 100083 P. R. China
| | - Yuting Hu
- Corrosion and Protection Center, University of Science and Technology Beijing Beijing 100083 P. R. China
| | - Chaofang Dong
- Corrosion and Protection Center, University of Science and Technology Beijing Beijing 100083 P. R. China
| | - Junsheng Wu
- Corrosion and Protection Center, University of Science and Technology Beijing Beijing 100083 P. R. China
| | - Xiaogang Li
- Corrosion and Protection Center, University of Science and Technology Beijing Beijing 100083 P. R. China.,Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences Ningbo 315201 P. R. China
| |
Collapse
|