scholarly journals The Survival of Haloferax mediterranei under Stressful Conditions

2021 ◽  
Vol 9 (2) ◽  
pp. 336
Author(s):  
Laura Matarredona ◽  
Mónica Camacho ◽  
Basilio Zafrilla ◽  
Gloria Bravo-Barrales ◽  
Julia Esclapez ◽  
...  

Haloarchaea can survive and thrive under exposure to a wide range of extreme environmental factors, which represents a potential interest to biotechnology. Growth responses to different stressful conditions were examined in the haloarchaeon Haloferax mediterranei R4. It has been demonstrated that this halophilic archaeon is able to grow between 10 and 32.5% (w/v) of sea water, at 32–52 °C, although it is expected to grow in temperatures lower than 32 °C, and between 5.75 and 8.75 of pH. Moreover, it can also grow under high metal concentrations (nickel, lithium, cobalt, arsenic), which are toxic to most living beings, making it a promising candidate for future biotechnological purposes and industrial applications. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis quantified the intracellular ion concentrations of these four metals in Hfx. mediterranei, concluding that this haloarchaeon can accumulate Li+, Co2+, As5+, and Ni2+ within the cell. This paper is the first report on Hfx. mediterranei in which multiple stress conditions have been studied to explore the mechanism of stress resistance. It constitutes the most detailed study in Haloarchaea, and, as a consequence, new biotechnological and industrial applications have emerged.

Author(s):  
Mark Golitko ◽  
Laure Dussubieux

Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is a versatile technique capable of measuring nearly every element on the Periodic Table down to extremely low concentrations. Using liquid sampling, it is a powerful method for bulk compositional characterization but has been only sporadically applied to archaeological ceramic studies. With laser ablation sampling, ICP-MS can be used to produce spatially resolved chemical information and has a wide range of archaeological applications including the analysis of ceramic surface treatments, paste composition, temper composition, and identification of post-burial chemical alteration. ICP-MS and LA-ICP-MS are particularly valuable when used in conjunction with bulk and mineralogical characterization techniques to elucidate which potential cultural, geological, or environmental effects are responsible for bulk compositional patterning, as well as providing complimentary compositional provenance information for individual phases of ceramic paste.


Nukleonika ◽  
2018 ◽  
Vol 63 (4) ◽  
pp. 131-137
Author(s):  
Marcin Rogowski ◽  
Tomasz Smoliński ◽  
Marta Pyszynska ◽  
Marcin Brykała ◽  
Andrzej G. Chmielewski

Abstract The use of radiotracers in the present study is intended to replace traditional steps of metal quantitative analysis (solution sampling and instrumental chemical analysis) and to allow real-time measurements of metal concentrations during the leaching process. In this study, 64Cu, an isotope of copper, was selected as a radiotracer. Samples of copper flotation tailings were irradiated in the Maria research reactor (Świerk, Poland) and mixed with an inactive portion of the milled fl otation waste. The leaching process was carried out in a glass reactor, and the radiation spectrum was measured using a gamma spectrometer. The material was then treated using various acids (sulphuric acid, nitric acid, acetic acid, citric acid, and ascorbic acid) in a wide range of their concentrations. Experiments with the radiotracer were conducted in sulphuric and nitric acids. The amount of the leached metal (copper) was calculated on the basis of the peak area ratio in the gamma-ray spectrum of the activated tailings and standard samples. Inductively coupled plasma mass spectrometry (ICP-MS) was also used to analyse the metal content. Maximum recovery of 56% Cu was achieved using 9 M HNO3, whereas the recovery was lowest for ascorbic acid (<1%). Both analytical methods were compared, and the results presented in this paper are in good agreement with radiometric measurements obtained using ICP-MS analysis.


2006 ◽  
Vol 10 ◽  
pp. 25-28 ◽  
Author(s):  
Dirk Frei ◽  
Julie A. Hollis ◽  
Axel Gerdes ◽  
Dan Harlov ◽  
Christine Karlsson ◽  
...  

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was developed in 1985 and the first commercial laser ablation systems were introduced in the mid 1990s. Since then, LA-ICP-MS has become an important analytical tool in the earth sciences. Initially, the main interest for geologists was in its ability to quantitatively determine the contents of a wide range of elements in many minerals at very low concentrations (a few ppm and below) with relatively high spatial resolution (spot diameters of typically 30–100 μm). The potential of LA-ICP-MS for rapid in situ U–Th–Pb geochronology was already realised in the early to mid 1990s. However, the full potential of LA-ICP-MS as the low-cost alternative to ion-microprobe techniques for highly precise and accurate in situ U–Th–Pb age dating was not realised until the relatively recent advances in laser technologies and the introduction of magnetic sectorfield ICP-MS (SF-ICPMS) instruments. In March 2005, the Geological Survey of Denmark and Greenland (GEUS) commissioned a new laser ablation magnetic sectorfield inductively coupled plasma mass spectrometry (LA-SF-ICP-MS) facility employing a ThermoFinnigan Element2 high resolution magnetic sectorfield ICP-MS and a Merchantek New Wave 213 nm UV laser ablation system. The new GEUS LA-SF-ICP-MS facility is widely used on Survey research projects in Denmark and Greenland, as well as in collaborative research and contract projects conducted with partners from academia and industry worldwide. Here, we present examples from some of the these ongoing studies that highlight the application of the new facility for advanced geochronological and trace element in situ microanalysis of geomaterials. The application of LASF-ICP-MS based in situ zircon geochronology to regional studies addressing the Archaean geology of southern West Greenland is presented by Hollis et al. (2006, this volume).


Geochronology ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 123-147
Author(s):  
Veronica Peverelli ◽  
Tanya Ewing ◽  
Daniela Rubatto ◽  
Martin Wille ◽  
Alfons Berger ◽  
...  

Abstract. Epidote – here defined as minerals belonging to the epidote–clinozoisite solid solution – is a low-μ (μ=238U/204Pb) mineral occurring in a variety of geological environments and participating in many metamorphic reactions that is stable throughout a wide range of pressure–temperature conditions. Despite containing fair amounts of U, its use as a U−Pb geochronometer has been hindered by the commonly high contents of initial Pb, with isotopic compositions that cannot be assumed a priori. We present a U−Pb geochronology of hydrothermal-vein epidote spanning a wide range of Pb (3.9–190 µg g−1), Th (0.01–38 µg g−1), and U (2.6–530 µg g−1) contents and with μ values between 7 and 510 from the Albula area (eastern Swiss Alps), from the Grimsel area (central Swiss Alps), and from the Heyuan fault (Guangdong Province, China). The investigated epidote samples show appreciable fractions of initial Pb contents (f206=0.7–1.0) – i.e., relative to radiogenic Pb – that vary to different extents. A protocol has been developed for in situ U−Pb dating of epidote by spot-analysis laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) with a magmatic allanite as the primary reference material. The suitability of the protocol and the reliability of the measured isotopic ratios have been ascertained by independent measurements of 238U/206Pb and 207Pb/206Pb ratios, respectively, with quadrupole and multicollector ICP-MS applied to epidote micro-separates digested and diluted in acids. For age calculation, we used the Tera–Wasserburg (207Pb/206Pb versus 238U/206Pb) diagram, which does not require corrections for initial Pb and provides the initial 207Pb/206Pb ratio. Petrographic and microstructural data indicate that the calculated ages date the crystallization of vein epidote from a hydrothermal fluid and that the U−Pb system was not reset to younger ages by later events. Vein epidote from the Albula area formed in the Paleocene (62.7±3.0 Ma) and is related to Alpine greenschist-facies metamorphism. The Miocene (19.2±4.3 and 16.9±3.7 Ma) epidote veins from the Grimsel area formed during the Handegg deformation phase (22–17 Ma) of the Alpine evolution of the Aar Massif. Identical initial 207Pb/206Pb ratios reveal homogeneity in Pb isotopic compositions of the fluid across ca. 100 m. Vein epidote from the Heyuan fault is Cretaceous in age ( 107.2±8.9 Ma) and formed during the early movements of the fault. In situ U−Pb analyses of epidote returned reliable ages of otherwise undatable epidote–quartz veins. The Tera–Wasserburg approach has proven pivotal for in situ U−Pb dating of epidote, and the decisive aspect for low age uncertainties is the variability in intra-sample initial Pb fractions.


2009 ◽  
Vol 31 (1) ◽  
pp. 46-49 ◽  
Author(s):  
Dominic Hare ◽  
David Bishop ◽  
Christine Austin ◽  
Philip Doble

Trace elements play a key role in a wide range of biological processes. A full understanding of those processes requires a knowledge not only of the genomics and proteomics of the organism, but also the distribution and concentration of trace elements. A new application of inductively coupled plasma mass spectrometry (ICP-MS) provides the capability to directly visualize trace elements in soft tissue, offering the promise of improved diagnosis and monitoring of disease.


2019 ◽  
Author(s):  
Ingo Strenge ◽  
Carsten Engelhard

<p>The article demonstrates the importance of using a suitable approach to compensate for dead time relate count losses (a certain measurement artefact) whenever short, but potentially strong transient signals are to be analysed using inductively coupled plasma mass spectrometry (ICP-MS). Findings strongly support the theory that inadequate time resolution, and therefore insufficient compensation for these count losses, is one of the main reasons for size underestimation observed when analysing inorganic nanoparticles using ICP-MS, a topic still controversially discussed.</p>


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