1
|
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
|
2
|
Häder DP, Braun M, Grimm D, Hemmersbach R. Gravireceptors in eukaryotes-a comparison of case studies on the cellular level. NPJ Microgravity 2017; 3:13. [PMID: 28649635 PMCID: PMC5460273 DOI: 10.1038/s41526-017-0018-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/27/2017] [Accepted: 03/09/2017] [Indexed: 01/03/2023] Open
Abstract
We have selected five evolutionary very different biological systems ranging from unicellular protists via algae and higher plants to human cells showing responses to the gravity vector of the Earth in order to compare their graviperception mechanisms. All these systems use a mass, which may either by a heavy statolith or the whole content of the cell heavier than the surrounding medium to operate on a gravireceptor either by exerting pressure or by pulling on a cytoskeletal element. In many cases the receptor seems to be a mechanosensitive ion channel activated by the gravitational force which allows a gated ion flux across the membrane when activated. This has been identified in many systems to be a calcium current, which in turn activates subsequent elements of the sensory transduction chain, such as calmodulin, which in turn results in the activation of ubiquitous enzymes, gene expression activation or silencing. Naturally, the subsequent responses to the gravity stimulus differ widely between the systems ranging from orientational movement and directed growth to physiological reactions and adaptation to the environmental conditions.
Collapse
Affiliation(s)
- Donat-P. Häder
- Erlangen-Nürnberg, Dept. Biol. Neue Str. 9, Emeritus from Friedrich-Alexander Universität, Möhrendorf, 91096 Germany
| | - Markus Braun
- Gravitational Biology, Universität Bonn, Kirschallee 1, Bonn, 53115 Germany
| | - Daniela Grimm
- Department of Biomedicine, Pharmacology, Aarhus University, Aarhus C, DK 8000 Denmark
| | - Ruth Hemmersbach
- Institute of Aerospace Medicine, Gravitational Biology, DLR (German Aerospace Center), Cologne, Linder Höhe 51147 Germany
| |
Collapse
|
3
|
Abstract
The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis.
Collapse
|
4
|
Krause M, Bräucker R, Hemmersbach R. Gravikinesis in Stylonychia mytilus is based on membrane potential changes. J Exp Biol 2010; 213:161-71. [DOI: 10.1242/jeb.030940] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
The graviperception of the hypotrichous ciliate Stylonychia mytilus was investigated using electrophysiological methods and behavioural analysis. It is shown that Stylonychia can sense gravity and thereby compensates sedimentation rate by a negative gravikinesis. The graviresponse consists of a velocity-regulating physiological component (negative gravikinesis) and an additional orientational component. The latter is largely based on a physical mechanism but might, in addition, be affected by the frequency of ciliary reversals, which is under physiological control. We show that the external stimulus of gravity is transformed to a physiological signal, activating mechanosensitive calcium and potassium channels. Earlier electrophysiological experiments revealed that these ion channels are distributed in the manner of two opposing gradients over the surface membrane. Here, we show, for the first time, records of gravireceptor potentials in Stylonychia that are presumably based on this two-gradient system of ion channels. The gravireceptor potentials had maximum amplitudes of approximately 4 mV and slow activation characteristics (0.03 mV s–1). The presumptive number of involved graviperceptive ion channels was calculated and correlates with the analysis of the locomotive behaviour.
Collapse
Affiliation(s)
- Martin Krause
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, D-44780 Bochum, Germany
| | | | - Ruth Hemmersbach
- DLR, Institute of Aerospace Medicine, Linder Höhe, D-51174 Köln, Germany
| |
Collapse
|
5
|
Syntichaki P, Tavernarakis N. Genetic Models of Mechanotransduction: The NematodeCaenorhabditis elegans. Physiol Rev 2004; 84:1097-153. [PMID: 15383649 DOI: 10.1152/physrev.00043.2003] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mechanotransduction, the conversion of a mechanical stimulus into a biological response, constitutes the basis for a plethora of fundamental biological processes such as the senses of touch, balance, and hearing and contributes critically to development and homeostasis in all organisms. Despite this profound importance in biology, we know remarkably little about how mechanical input forces delivered to a cell are interpreted to an extensive repertoire of output physiological responses. Recent, elegant genetic and electrophysiological studies have shown that specialized macromolecular complexes, encompassing mechanically gated ion channels, play a central role in the transformation of mechanical forces into a cellular signal, which takes place in mechanosensory organs of diverse organisms. These complexes are highly efficient sensors, closely entangled with their surrounding environment. Such association appears essential for proper channel gating and provides proximity of the mechanosensory apparatus to the source of triggering mechanical energy. Genetic and molecular evidence collected in model organisms such as the nematode worm Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and the mouse highlight two distinct classes of mechanically gated ion channels: the degenerin (DEG)/epithelial Na+channel (ENaC) family and the transient receptor potential (TRP) family of ion channels. In addition to the core channel proteins, several other potentially interacting molecules have in some cases been identified, which are likely parts of the mechanotransducing apparatus. Based on cumulative data, a model of the sensory mechanotransducer has emerged that encompasses our current understanding of the process and fulfills the structural requirements dictated by its dedicated function. It remains to be seen how general this model is and whether it will withstand the impiteous test of time.
Collapse
Affiliation(s)
- Popi Syntichaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Vassilika Vouton, PO Box 1527, Heraklion 71110, Crete, Greece
| | | |
Collapse
|