scholarly journals Temperature and pressure adaptation of a sulfate reducer from the deep subsurface

2015 ◽  
Vol 6 ◽  
Author(s):  
Katja Fichtel ◽  
Jörn Logemann ◽  
Jörg Fichtel ◽  
Jürgen Rullkötter ◽  
Heribert Cypionka ◽  
...  
Keyword(s):  
Sulfate Reducer ◽  
Deep Subsurface ◽  
Pressure Adaptation ◽  
Temperature And Pressure

scholarly journals Effects of temperatures and high pressures on the growth and survivability of methanogens and stable carbon isotope fractionation: implications for deep subsurface life on Mars

2018 ◽  
pp. 1-7
Author(s):  
Navita Sinha ◽  
Sudip Nepal ◽  
Timothy Kral ◽  
Pradeep Kumar
Keyword(s):  
Methane Concentration ◽  
High Pressures ◽  
Stable Carbon Isotope ◽  
Isotopic Fractionation ◽  
Methanogenic Archaea ◽  
Stable Carbon ◽  
Isotopic Data ◽  
Deep Subsurface ◽  
Carbon Isotopic ◽  
Temperature And Pressure

AbstractIn order to examine the potential survivability of life in the Martian deep subsurface, we have investigated the effects of temperature (45°C, 55°C and 65°C) and pressure (1, 400, 800 and 1200 atm) on the growth, carbon isotopic data and morphology of chemolithoautotrophic anaerobic methanogenic archaea,Methanothermobacter wolfeii. The growth and survivability of this methanogen were determined by measuring the methane concentration in headspace gas samples after the cells were returned to their conventional growth conditions. Interestingly, this methanogen survived at all the temperatures and pressures tested.M. wolfeiidemonstrated the highest methane concentration following exposure to pressure of 800 atm and a temperature of 65°C. We found that the stable carbon isotopic fractionation of methane, δ13C(CH4), was slightly more enriched in12C at 1 atm and 55°C than the carbon isotopic data obtained in other temperature and pressure conditions. A comparison of the images of the cells before and after the exposure to different temperatures and pressures did not show any obvious alteration in the morphology ofM. wolfeii. The research reported here suggests that at least one methanogen,M. wolfeii, may be able to survive under hypothetical Martian subsurface conditions with respect to temperature and pressure.

scholarly journals The deep-subsurface sulfate reducer Desulfotomaculum kuznetsovii employs two methanol-degrading pathways

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Diana Z. Sousa ◽  
Michael Visser ◽  
Antonie H. van Gelder ◽  
Sjef Boeren ◽  
Mervin M. Pieterse ◽  
...  
Keyword(s):  
Sulfate Reducer ◽  
Deep Subsurface

scholarly journals Effects of Temperatures and High Pressures on the Growth and Survivability of Methanogens and Stable Carbon Isotope Fractionation: Implications for Deep Subsurface Life on Mars

2018 ◽  
Author(s):  
Navita Sinha ◽  
Sudip Nepal ◽  
Timothy Kral ◽  
Pradeep Kumar
Keyword(s):  
Methane Concentration ◽  
High Pressures ◽  
Stable Carbon Isotope ◽  
Isotopic Fractionation ◽  
Methanogenic Archaea ◽  
Stable Carbon ◽  
Isotopic Data ◽  
Deep Subsurface ◽  
Carbon Isotopic ◽  
Temperature And Pressure

AbstractIn order to examine the potential survivability of life in the Martian deep subsurface, we have investigated the effects of temperature (45°C, 55°C, and 65°C) and pressure (1 atm, 400 atm, 800 atm, and 1200 atm) on the growth, carbon isotopic data, and morphology of chemolithoautotrophic anaerobic methanogenic archaea,Methanothermobacter wolfeii. The growth and survivability of this methanogen were determined by measuring the methane concentration in headspace gas samples after the cells were returned to their conventional growth conditions. Interestingly, this methanogen survived at all the temperatures and pressures tested.M. wolfeiidemonstrated the highest methane concentration following exposure to pressure of 800 atm and a temperature of 65°C. We found that the stable carbon isotopic fractionation of methane, δ13C(CH4), was slightly more enriched in12C at 1 atm and 55°C than the carbon isotopic data obtained in other temperature and pressure conditions. A comparison of the images of the cells before and after the exposure to different temperatures and pressures did not show any obvious alteration in the morphology ofM. wolfeii. The research reported here suggests that at least one methanogen,M. wolfeii, may be able to survive under hypothetical Martian subsurface conditions with respect to temperature and pressure.

scholarly journals Temperature and pressure adaptation of the binding site of acetylcholinesterase

1974 ◽  
Vol 143 (3) ◽  
pp. 535-539 ◽  
Author(s):  
Peter W. Hochachka
Keyword(s):  
Low Temperatures ◽  
High Pressures ◽  
Carbon Substrate ◽  
Anionic Site ◽  
Binding Region ◽  
Physical Environments ◽  
Hydrophobic Binding ◽  
Pressure Adaptation ◽  
Temperature And Pressure ◽  
Brain Acetylcholinesterase

1. Studies with a carbon substrate analogue, 3,3-dimethylbutyl acetate, indicate that the hydrophobic contribution to binding at the anionic site of acetylcholinesterase is strongly disrupted at low temperatures and high pressures. 2. Animals living in different physical environments circumvent this problem by adjusting the enthalpic and entropic contributions to binding. 3. An extreme example of this adaptational strategy is supplied by brain acetylcholinesterase extracted from an abyssal fish living at 2°C and up to several hundred atmospheres of pressure. This acetylcholinesterase appears to have a smaller hydrophobic binding region in the anionic site, playing a measurably decreased role in ligand binding.

scholarly journals Ions in the Deep Subsurface of Earth, Mars, and Icy Moons: Their Effects in Combination with Temperature and Pressure on tRNA–Ligand Binding

2021 ◽  
Vol 22 (19) ◽  
pp. 10861
Author(s):  
Nisrine Jahmidi-Azizi ◽  
Stewart Gault ◽  
Charles S. Cockell ◽  
Rosario Oliva ◽  
Roland Winter
Keyword(s):  
Complex Formation ◽  
Ligand Binding ◽  
High Pressures ◽  
Deep Subsurface ◽  
Biochemical Processes ◽  
Icy Moons ◽  
Ligand Interactions ◽  
Temperature And Pressure ◽  
High Concentrations ◽  
Harsh Conditions

The interactions of ligands with nucleic acids are central to numerous reactions in the biological cell. How such reactions are affected by harsh environmental conditions such as low temperatures, high pressures, and high concentrations of destructive ions is still largely unknown. To elucidate the ions’ role in shaping habitability in extraterrestrial environments and the deep subsurface of Earth with respect to fundamental biochemical processes, we investigated the effect of selected salts (MgCl2, MgSO4, and Mg(ClO4)2) and high hydrostatic pressure (relevant for the subsurface of that planet) on the complex formation between tRNA and the ligand ThT. The results show that Mg2+ salts reduce the binding tendency of ThT to tRNA. This effect is largely due to the interaction of ThT with the salt anions, which leads to a strong decrease in the activity of the ligand. However, at mM concentrations, binding is still favored. The ions alter the thermodynamics of binding, rendering complex formation that is more entropy driven. Remarkably, the pressure favors ligand binding regardless of the type of salt. Although the binding constant is reduced, the harsh conditions in the subsurface of Earth, Mars, and icy moons do not necessarily preclude nucleic acid–ligand interactions of the type studied here.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

ESEM - A multipurpose surface Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 632-633 ◽  
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Environmental Scanning ◽  
Gas Composition ◽  
Saturated Water Vapor ◽  
Surface Electron ◽  
Current State ◽  
Saturated Water ◽  
New Type ◽  
Temperature And Pressure

Over recent years a new type of electron microscope - the environmental scanning electron microscope (ESEM) - has been developed for the examination of specimen surfaces in the presence of gases. A detailed series of reports on the system has appeared elsewhere. A review summary of the current state and potential of the system is presented here.The gas composition, temperature and pressure can be varied in the specimen chamber of the ESEM. With air, the pressure can be up to one atmosphere (about 1000 mbar). Environments with fully saturated water vapor only at room temperature (20-30 mbar) can be easily maintained whilst liquid water or other solutions, together with uncoated specimens, can be imaged routinely during various applications.

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