2. How microbes operate

2014 ◽  
Author(s):  
Nicholas P. Money
Keyword(s):  
Energy Source ◽  
Liquid Water ◽  
Environmental Variables ◽  
Chemical Energy ◽  
Available P ◽  
Biochemical Reactions ◽  
Microbial Life ◽  
Eukaryotic Microorganisms ◽  
Additional Constraints ◽  
In Cells

‘How microbes operate’ considers the mechanisms that sustain prokaryotic and eukaryotic microorganisms. All active cells must be supplied with water and an energy source. Absorption of water is essential, even in extremely dry or salty habitats, because the enzymes that catalyse biochemical reactions in cells do not work unless they are hydrated. Sunlight powers the metabolism of photosynthetic microbes and others glean chemical energy from a plenitude of terrestrial sources. Extremes in temperature, acidity, and other environmental variables place additional constraints upon microbial life, but bacteria, archaea, and eukaryotic microorganisms thrive in most places where liquid water is available.

scholarly journals Positional isomers of a non-nucleoside substrate differentially affect myosin function

2019 ◽  
Author(s):  
M. Woodward ◽  
E. Ostrander ◽  
S.P. Jeong ◽  
X. Liu ◽  
B. Scott ◽  
...  
Keyword(s):  
Energy Source ◽  
Muscle Contraction ◽  
Motor Function ◽  
Molecular Motors ◽  
Molecular Motor ◽  
Vesicular Transport ◽  
Gain Control ◽  
Mechanical Work ◽  
Chemical Energy ◽  
Muscle Myosin

AbstractMolecular motors have evolved to transduce chemical energy from adenosine triphosphate into mechanical work to drive essential cellular processes, from muscle contraction to vesicular transport. Dysfunction of these motors is a root cause of many pathologies necessitating the need for intrinsic control over molecular motor function. Herein, we demonstrate that positional isomerism can be used as a simple and powerful tool to control the molecular motor of muscle, myosin. Using three isomers of a synthetic non-nucleoside triphosphate we demonstrate that myosin’s force and motion generating capacity can be dramatically altered at both the ensemble and single molecule levels. By correlating our experimental results with computation, we show that each isomer exerts intrinsic control by affecting distinct steps in myosin’s mechano-chemical cycle. Our studies demonstrate that subtle variations in the structure of an abiotic energy source can be used to control the force and motility of myosin without altering myosin’s structure.Statement of SignificanceMolecular motors transduce chemical energy from ATP into the mechanical work inside a cell, powering everything from muscle contraction to vesicular transport. While ATP is the preferred source of energy, there is growing interest in developing alternative sources of energy to gain control over molecular motors. We synthesized a series of synthetic compounds to serve as alternative energy sources for muscle myosin. Myosin was able to use this energy source to generate force and velocity. And by using different isomers of this compound we were able to modulate, and even inhibit, the activity of myosin. This suggests that changing the isomer of the substrate could provide a simple, yet powerful, approach to gain control over molecular motor function.

scholarly journals A New Record for Microbial Perchlorate Tolerance: Fungal Growth in NaClO4 Brines and its Implications for Putative Life on Mars

Life ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 53 ◽  
Author(s):  
Jacob Heinz ◽  
Tim Krahn ◽  
Dirk Schulze-Makuch
Keyword(s):  
Liquid Water ◽  
Sodium Perchlorate ◽  
Debaryomyces Hansenii ◽  
Fungal Growth ◽  
Natural Environments ◽  
Microbial Life ◽  
Purpureocillium Lilacinum ◽  
Halotolerant Yeast ◽  
Colony Forming Units ◽  
Microbial Habitat

The habitability of Mars is strongly dependent on the availability of liquid water, which is essential for life as we know it. One of the few places where liquid water might be found on Mars is in liquid perchlorate brines that could form via deliquescence. As these concentrated perchlorate salt solutions do not occur on Earth as natural environments, it is necessary to investigate in lab experiments the potential of these brines to serve as a microbial habitat. Here, we report on the sodium perchlorate (NaClO4) tolerances for the halotolerant yeast Debaryomyces hansenii and the filamentous fungus Purpureocillium lilacinum. Microbial growth was determined visually, microscopically and via counting colony forming units (CFU). With the observed growth of D. hansenii in liquid growth medium containing 2.4 M NaClO4, we found by far the highest microbial perchlorate tolerance reported to date, more than twice as high as the record reported prior (for the bacterium Planococcus halocryophilus). It is plausible to assume that putative Martian microbes could adapt to even higher perchlorate concentrations due to their long exposure to these environments occurring naturally on Mars, which also increases the likelihood of microbial life thriving in the Martian brines.

scholarly journals Enhancing Photoelectrochemical Water Splitting with Plasmonic Au Nanoparticles

2021 ◽  
Author(s):  
Cheon Woo Moon ◽  
Min-Ju Choi ◽  
Jerome Hyun ◽  
Ho Won Jang
Keyword(s):  
Energy Source ◽  
Solar Energy ◽  
Water Splitting ◽  
Renewable Resources ◽  
Au Nanoparticles ◽  
Environmental Issues ◽  
Photoelectrochemical Water Splitting ◽  
Chemical Energy ◽  
Energy Cycle ◽  
Water Based

The water-based renewable chemical energy cycle has attracted interest for its role in replacing existing non-renewable resources and alleviating environmental issues. Utilizing the semi-infinite solar energy source is the most...

scholarly journals Structure and Statistical Analysis of the Microphysical Properties of Generating Cells in the Comma Head Region of Continental Winter Cyclones

2014 ◽  
Vol 71 (11) ◽  
pp. 4181-4203 ◽  
Author(s):  
David M. Plummer ◽  
Greg M. McFarquhar ◽  
Robert M. Rauber ◽  
Brian F. Jewett ◽  
David C. Leon
Keyword(s):  
Liquid Water ◽  
Water Saturation ◽  
Supercooled Water ◽  
Particle Growth ◽  
Liquid Water Content ◽  
Head Region ◽  
Temperature Range ◽  
Microphysical Properties ◽  
The Impact ◽  
In Cells

Abstract This paper presents analyses of the microphysical structure of cloud-top convective generating cells at temperatures between −10° and −55°C across the comma head of 11 continental cyclones, using data collected by the W-band Wyoming Cloud Radar and in situ instrumentation aboard the National Science Foundation (NSF)/NCAR C-130. A case study of one cyclone is presented, followed by statistical analyses of the entire dataset. Ice particle number concentrations averaged 1.9 times larger inside generating cells compared to outside, and derived ice water contents and median mass diameters averaged 2.2 and 1.1 times larger in cells, respectively. Supercooled water was directly measured at temperatures between −31.4° and −11.1°C, with the median and 95th-percentile liquid water content increasing from ~0.09 to 0.12 g m−3 and 0.14 to 0.28 g m−3 over this temperature range, respectively. Liquid water was present in 26% of observations within cells and 18% of observations between cells over the same temperature range, and it was nearly ubiquitous at temperatures above −16°C. The larger ice particle concentrations in cells are consistent with greater ice production in convective updrafts. The increased mass and diameter of the ice particles demonstrate that generating cells provide environments favorable for enhanced particle growth. The impact of water saturation and supercooled water in the cells was evident, with rapid particle growth by diffusion and sometimes riming apparent, in addition to aggregation. Turbulent mixing lessened the observed differences between cells and surrounding regions, with supercooled water observed within and between cells, similar habits within and between cells, and rimed particles evident even in ice-phase conditions.

scholarly journals Biogaz jako alternatywny nośnik energii

2014 ◽  
Vol 12 (2) ◽  
pp. 135-154
Author(s):  
Ewelina Podeszwa ◽  
Krzysztof Biernat
Keyword(s):  
Energy Source ◽  
Alternative Energy ◽  
Chemical Energy ◽  
Alternative Energy Source

The advantages of biogas, apart from being just an alternative energy source, are its various possibilities of conversion. Chemical energy can be converted into biogas for heat, electricity and chemical energy of other compounds. Therefore, there are numerous opportunities for using energy from biogas. Some of them are used in stationary installations. Another application is as a fuel for vehicle engines by burning biomethane.

scholarly journals Interactions with Arsenic: Mechanisms of Toxicity and Cellular Resistance in Eukaryotic Microorganisms

2021 ◽  
Vol 18 (22) ◽  
pp. 12226
Author(s):  
Patricia De Francisco ◽  
Ana Martín-González ◽  
Daniel Rodriguez-Martín ◽  
Silvia Díaz
Keyword(s):  
Public Health ◽  
Energy Source ◽  
Selective Pressure ◽  
Cellular Resistance ◽  
Mechanisms Of Toxicity ◽  
Eukaryotic Microorganisms ◽  
Microbial Remediation ◽  
Eukaryotic Microbes ◽  
Detoxification Mechanisms ◽  
Environmental Challenge

Arsenic (As) is quite an abundant metalloid, with ancient origin and ubiquitous distribution, which represents a severe environmental risk and a global problem for public health. Microbial exposure to As compounds in the environment has happened since the beginning of time. Selective pressure has induced the evolution of various genetic systems conferring useful capacities in many microorganisms to detoxify and even use arsenic, as an energy source. This review summarizes the microbial impact of the As biogeochemical cycle. Moreover, the poorly known adverse effects of this element on eukaryotic microbes, as well as the As uptake and detoxification mechanisms developed by yeast and protists, are discussed. Finally, an outlook of As microbial remediation makes evident the knowledge gaps and the necessity of new approaches to mitigate this environmental challenge.

Photopolymerization performed under dark condition using long stored electrons in carbon nitride

2021 ◽  
Author(s):  
Guang Chen ◽  
Zidan Zhang ◽  
Wen-Jian Zhang ◽  
Lei Xia ◽  
Xuan Nie ◽  
...  
Keyword(s):  
Carbon Nitride ◽  
Chemical Energy ◽  
Dark Condition ◽  
Biochemical Reactions

In nature, the stored chemical energy and electrons as ATP and NADPH generated during irradiation could facilitate biochemical reactions under dark condition. However, in artificial photoreaction systems, it is still...

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