Potential of Acidithiobacillus ferrooxidans to Grow on and Bioleach Metals from Mars and Lunar Regolith Simulants under Simulated Microgravity Conditions

The biomining microbes which extract metals from ores that have been applied in mining processes worldwide hold potential for harnessing space resources. Their cell growth and ability to extract metals from extraterrestrial minerals under microgravity environments, however, remains largely unknown. The present study used the model biomining bacterium Acidithiobacillus ferrooxidans to extract metals from lunar and Martian regolith simulants cultivated in a rotating clinostat with matched controls grown under the influence of terrestrial gravity. Analyses included assessments of final cell count, size, morphology, and soluble metal concentrations. Under Earth gravity, with the addition of Fe3+ and H2/CO2, A. ferrooxidans grew in the presence of regolith simulants to a final cell density comparable to controls without regoliths. The simulated microgravity appeared to enable cells to grow to a higher cell density in the presence of lunar regolith simulants. Clinostat cultures of A. ferrooxidans solubilised higher amounts of Si, Mn and Mg from lunar and Martian regolith simulants than abiotic controls. Electron microscopy observations revealed that microgravity stimulated the biosynthesis of intracellular nanoparticles (most likely magnetite) in anaerobically grown A. ferrooxidans cells. These results suggested that A. ferrooxidans has the potential for metal bioleaching and the production of useful nanoparticles in space.

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Effects of altered gravity induced by clinorotation on the cholinesterase activity of the non-sentient model Paramecium primaurelia (Protozoa)

Journal of Biological Research - Bollettino della Società Italiana di Biologia Sperimentale ◽

10.4081/jbr.2018.7034 ◽

2018 ◽

Vol 91 (1) ◽

Author(s):

Francesca Sardi ◽

Martina Rossi ◽

Sara Ferrando ◽

Maria Angela Masini ◽

Federico Biggi ◽

...

Keyword(s):

Simulated Microgravity ◽

Cholinesterase Activity ◽

Developmental Cycle ◽

Unicellular Organism ◽

Altered Gravity ◽

Random Positioning Machine ◽

Earth Gravity ◽

Microgravity Conditions ◽

Living Organisms ◽

Chemical Mediators

Compounds known as chemical mediators, including acetylcholine, have been found not only in humans and animals, but also in living organisms, like protozoa, which lack nervous system. In Paramecium primaurelia has been described a cholinergic system, which is proven to play an important role in cell-cell interactions during its developmental cycle. In our work we investigated the effects of exposure to simulated microgravity (3D Random Positioning Machine, 56 rpm, 10-6 g) on the cholinesterase activity of the eukaryote unicellular-organism alternative-model P. primaurelia. Our results show that the exposure of P. primaurelia to microgravity for 6 h, 24 h, 48 h affects the localization and the amount of cholinesterase activity compared to cells grown under Earth gravity conditions (1 g). However, these effects are transient since P. primaurelia restores its normal cholinesterase activity after 72 h under microgravity conditions, as well as cells exposed up to 72 h to microgravity and then placed under terrestrial gravity for 48 h.

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Alterations in the Virulence Potential of Enteric Pathogens and Bacterial–Host Cell Interactions Under Simulated Microgravity Conditions

Journal of Toxicology and Environmental Health Part A ◽

10.1080/15287390500361792 ◽

2006 ◽

Vol 69 (14) ◽

pp. 1345-1370 ◽

Cited By ~ 53

Author(s):

V. Chopra ◽

A. A. Fadl ◽

J. Sha ◽

S. Chopra ◽

C. L. Galindo ◽

...

Keyword(s):

Host Cell ◽

Simulated Microgravity ◽

Cell Interactions ◽

Enteric Pathogens ◽

Bacterial Host ◽

Virulence Potential ◽

Host Cell Interactions ◽

Microgravity Conditions

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Scalable Microgravity Simulator Used for Long-Term Musculoskeletal Cells and Tissue Engineering

International Journal of Molecular Sciences ◽

10.3390/ijms21238908 ◽

2020 ◽

Vol 21 (23) ◽

pp. 8908

Author(s):

Alessandra Cazzaniga ◽

Fabian Ille ◽

Simon Wuest ◽

Carsten Haack ◽

Adrian Koller ◽

...

Keyword(s):

Tissue Engineering ◽

Simulated Microgravity ◽

Culture Media ◽

Three Dimensions ◽

C2c12 Cells ◽

Equal Treatment ◽

New Device ◽

Microgravity Conditions ◽

Validation Tests

We introduce a new benchtop microgravity simulator (MGS) that is scalable and easy to use. Its working principle is similar to that of random positioning machines (RPM), commonly used in research laboratories and regarded as one of the gold standards for simulating microgravity. The improvement of the MGS concerns mainly the algorithms controlling the movements of the samples and the design that, for the first time, guarantees equal treatment of all the culture flasks undergoing simulated microgravity. Qualification and validation tests of the new device were conducted with human bone marrow stem cells (bMSC) and mouse skeletal muscle myoblasts (C2C12). bMSC were cultured for 4 days on the MGS and the RPM in parallel. In the presence of osteogenic medium, an overexpression of osteogenic markers was detected in the samples from both devices. Similarly, C2C12 cells were maintained for 4 days on the MGS and the rotating wall vessel (RWV) device, another widely used microgravity simulator. Significant downregulation of myogenesis markers was observed in gravitationally unloaded cells. Therefore, similar results can be obtained regardless of the used simulated microgravity devices, namely MGS, RPM, or RWV. The newly developed MGS device thus offers easy and reliable long-term cell culture possibilities under simulated microgravity conditions. Currently, upgrades are in progress to allow real-time monitoring of the culture media and liquids exchange while running. This is of particular interest for long-term cultivation, needed for tissue engineering applications. Tissue grown under real or simulated microgravity has specific features, such as growth in three-dimensions (3D). Growth in weightlessness conditions fosters mechanical, structural, and chemical interactions between cells and the extracellular matrix in any direction.

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Physiological Responses of Jurkat Lymphocytes to Simulated Microgravity Conditions

International Journal of Molecular Sciences ◽

10.3390/ijms20081892 ◽

2019 ◽

Vol 20 (8) ◽

pp. 1892 ◽

Cited By ~ 3

Author(s):

Caterina Morabito ◽

Paola Lanuti ◽

Giusy A. Caprara ◽

Marco Marchisio ◽

Mariano Bizzarri ◽

...

Keyword(s):

Simulated Microgravity ◽

Immune Cell ◽

Cellular Level ◽

The Body ◽

Jurkat Cells ◽

Cell Phenotype ◽

Environmental Condition ◽

Mitochondria Membrane Potential ◽

Microgravity Conditions ◽

External Forces

The presence of microgravity conditions deeply affects the human body functions at the systemic, organ and cellular levels. This study aimed to investigate the effects induced by simulated-microgravity on non-stimulated Jurkat lymphocytes, an immune cell phenotype considered as a biosensor of the body responses, in order to depict at the cellular level the effects of such a peculiar condition. Jurkat cells were grown at 1 g or on random positioning machine simulating microgravity. On these cells we performed: morphological, cell cycle and proliferation analyses using cytofluorimetric and staining protocols—intracellular Ca2+, reactive oxygen species (ROS), mitochondria membrane potential and O2− measurements using fluorescent probes—aconitase and mitochondria activity, glucose and lactate content using colorimetric assays. After the first exposure days, the cells showed a more homogeneous roundish shape, an increased proliferation rate, metabolic and detoxifying activity resulted in decreased intracellular Ca2+ and ROS. In the late exposure time, the cells adapted to the new environmental condition. Our non-activated proliferating Jurkat cells, even if responsive to altered external forces, adapted to the new environmental condition showing a healthy status. In order to define the cellular mechanism(s) triggered by microgravity, developing standardized experimental approaches and controlled cell culture and simulator conditions is strongly recommended.

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Calpain activation mediates microgravity-induced myocardial abnormalities in mice via p38 and ERK1/2 MAPK pathways

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.011890 ◽

2020 ◽

Vol 295 (49) ◽

pp. 16840-16851

Author(s):

Liwen Liang ◽

Huili Li ◽

Ting Cao ◽

Lina Qu ◽

Lulu Zhang ◽

...

Keyword(s):

Nadph Oxidase ◽

Simulated Microgravity ◽

Heart Weight ◽

Calpain Inhibitor ◽

Protective Effects ◽

Tail Suspension ◽

Calpain Activation ◽

Microgravity Conditions ◽

Underlying Mechanisms ◽

Nadph Oxidase Activation

The human cardiovascular system has adapted to function optimally in Earth's 1G gravity, and microgravity conditions cause myocardial abnormalities, including atrophy and dysfunction. However, the underlying mechanisms linking microgravity and cardiac anomalies are incompletely understood. In this study, we investigated whether and how calpain activation promotes myocardial abnormalities under simulated microgravity conditions. Simulated microgravity was induced by tail suspension in mice with cardiomyocyte-specific deletion of Capns1, which disrupts activity and stability of calpain-1 and calpain-2, and their WT littermates. Tail suspension time-dependently reduced cardiomyocyte size, heart weight, and myocardial function in WT mice, and these changes were accompanied by calpain activation, NADPH oxidase activation, and oxidative stress in heart tissues. The effects of tail suspension were attenuated by deletion of Capns1. Notably, the protective effects of Capns1 deletion were associated with the prevention of phosphorylation of Ser-345 on p47phox and attenuation of ERK1/2 and p38 activation in hearts of tail-suspended mice. Using a rotary cell culture system, we simulated microgravity in cultured neonatal mouse cardiomyocytes and observed decreased total protein/DNA ratio and induced calpain activation, phosphorylation of Ser-345 on p47phox, and activation of ERK1/2 and p38, all of which were prevented by calpain inhibitor-III. Furthermore, inhibition of ERK1/2 or p38 attenuated phosphorylation of Ser-345 on p47phox in cardiomyocytes under simulated microgravity. This study demonstrates for the first time that calpain promotes NADPH oxidase activation and myocardial abnormalities under microgravity by facilitating p47phox phosphorylation via ERK1/2 and p38 pathways. Thus, calpain inhibition may be an effective therapeutic approach to reduce microgravity-induced myocardial abnormalities.

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Reduction of Selenite and Detoxification of Elemental Selenium by the Phototrophic BacteriumRhodospirillum rubrum

Applied and Environmental Microbiology ◽

10.1128/aem.65.11.4734-4740.1999 ◽

1999 ◽

Vol 65 (11) ◽

pp. 4734-4740 ◽

Cited By ~ 150

Author(s):

J. Kessi ◽

M. Ramuz ◽

E. Wehrli ◽

M. Spycher ◽

R. Bachofen

Keyword(s):

Cell Wall ◽

Plasma Membrane ◽

Cell Density ◽

Culture Medium ◽

Rhodospirillum Rubrum ◽

Buoyant Density ◽

Elemental Selenium ◽

Selenite Reduction ◽

Final Cell Density ◽

Cell Densities

ABSTRACT The effect of selenite on growth kinetics, the ability of cultures to reduce selenite, and the mechanism of detoxification of selenium were investigated by using Rhodospirillum rubrum. Anoxic photosynthetic cultures were able to completely reduce as much as 1.5 mM selenite, whereas in aerobic cultures a 0.5 mM selenite concentration was only reduced to about 0.375 mM. The presence of selenite in the culture medium strongly affected cell division. In the presence of a selenite concentration of 1.5 mM cultures reached final cell densities that were only about 15% of the control final cell density. The cell density remained nearly constant during the stationary phase for all of the selenite concentrations tested, showing that the cells were not severely damaged by the presence of selenite or elemental selenium. Particles containing elemental selenium were observed in the cytoplasm, which led to an increase in the buoyant density of the cells. Interestingly, the change in the buoyant density was reversed after selenite reduction was complete; the buoyant density of the cells returned to the buoyant density of the control cells. This demonstrated that R. rubrum expels elemental selenium across the plasma membrane and the cell wall. Accordingly, electron-dense particles were more numerous in the cells during the reduction phase than after the reduction phase.

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