scholarly journals Decoupled carbonate chemistry controls on the incorporation of boron into <i>Orbulina universa</i>

2017 ◽  
Vol 14 (2) ◽  
pp. 415-430 ◽  
Author(s):  
Ella L. Howes ◽  
Karina Kaczmarek ◽  
Markus Raitzsch ◽  
Antje Mewes ◽  
Nienke Bijma ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Inductively Coupled Plasma ◽  
Culture Media ◽  
Boron Uptake ◽  
Carbonate System ◽  
Ample Evidence ◽  
System Parameters ◽  
Effects Of Ph ◽  
Orbulina Universa ◽  
Primary Relationship

Abstract. In order to fully constrain paleo-carbonate systems, proxies for two out of seven parameters, plus temperature and salinity, are required. The boron isotopic composition (δ11B) of planktonic foraminifera shells is a powerful tool for reconstructing changes in past surface ocean pH. As B(OH)4− is substituted into the biogenic calcite lattice in place of CO32−, and both borate and carbonate ions are more abundant at higher pH, it was suggested early on that B ∕ Ca ratios in biogenic calcite may serve as a proxy for [CO32−]. Although several recent studies have shown that a direct connection of B ∕ Ca to carbonate system parameters may be masked by other environmental factors in the field, there is ample evidence for a mechanistic relationship between B ∕ Ca and carbonate system parameters. Here, we focus on investigating the primary relationship to develop a mechanistic understanding of boron uptake. Differentiating between the effects of pH and [CO32−] is problematic, as they co-vary closely in natural systems, so the major control on boron incorporation remains unclear. To deconvolve the effects of pH and [CO32−] and to investigate their impact on the B ∕ Ca ratio and δ11B, we conducted culture experiments with the planktonic foraminifer Orbulina universa in manipulated culture media: constant pH (8.05), but changing [CO32−] (238, 286 and 534 µmol kg−1 CO32−) and at constant [CO32−] (276 ± 19.5 µmol kg−1) and varying pH (7.7, 7.9 and 8.05). Measurements of the isotopic composition of boron and the B ∕ Ca ratio were performed simultaneously using a femtosecond laser ablation system coupled to a MC-ICP-MS (multiple-collector inductively coupled plasma mass spectrometer). Our results show that, as expected, δ11B is controlled by pH but it is also modulated by [CO32−]. On the other hand, the B ∕ Ca ratio is driven by [HCO3−], independently of pH. This suggests that B ∕ Ca ratios in foraminiferal calcite can possibly be used as a second, independent, proxy for complete paleo-carbonate system reconstructions. This is discussed in light of recent literature demonstrating that the primary relationship between B ∕ Ca and [HCO3−] can be obscured by other environmental parameters.

scholarly journals Boron incorporation in the foraminifer <i>Amphistegina lessonii</i> under a decoupled carbonate chemistry

2014 ◽  
Vol 11 (12) ◽  
pp. 16743-16771 ◽  
Author(s):  
K. Kaczmarek ◽  
G. Langer ◽  
G. Nehrke ◽  
I. Horn ◽  
S. Misra ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Culture Media ◽  
Optical Emission ◽  
Boron Uptake ◽  
Carbonate Chemistry ◽  
Carbonate System ◽  
Field Samples ◽  
Species Specific ◽  
Boron Isotopic Composition

Abstract. A number of studies have shown that the boron isotopic composition (δ11B) and the B/Ca ratio of biogenic carbonates (mostly foraminifers) can serve as proxies for two parameters of the ocean's carbonate chemistry, rendering it possible to calculate the entire carbonate system. However, the B incorporation mechanism into marine carbonates is still not fully understood and analyses of field samples show species specific and hydrographic effects on the B proxies complicating their application. Identifying the carbonate system parameter influencing boron incorporation is difficult due to the co-variation of pH, CO32-, and B(OH)4-. To shed light on the question which parameter of the carbonate system is related to the boron incorporation, we performed culture experiments with the benthic symbiont-bearing foraminifer Amphistegina lessonii using a decoupled pH–CO32- chemistry. The determination of the boron isotopic composition and B/Ca ratios was performed simultaneously by means of a new in situ technique combining optical emission spectroscopy and laser ablation MC-ICP-MS. The boron isotopic composition in the tests gets heavier with increasing pH and B/Ca increases with increasing BOH4-/HCO3- of the culture media. The latter indicates that boron uptake of A. lessonii features a competition between B(OH)4- and HCO3-. Furthermore, the simultaneous determination of B/Ca and δ11B on single specimens allows for assessing the relative variability of these parameters. Among different treatments the B/Ca shows an increasing variability with increasing boron concentration in the test whereas the variability in the isotope distribution is constant.

scholarly journals Boron incorporation in the foraminifer <i>Amphistegina lessonii</i> under a decoupled carbonate chemistry

2015 ◽  
Vol 12 (6) ◽  
pp. 1753-1763 ◽  
Author(s):  
K. Kaczmarek ◽  
G. Langer ◽  
G. Nehrke ◽  
I. Horn ◽  
S. Misra ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Culture Media ◽  
Optical Emission ◽  
Boron Uptake ◽  
Carbonate Chemistry ◽  
Carbonate System ◽  
Field Samples ◽  
Species Specific ◽  
Boron Isotopic Composition

Abstract. A number of studies have shown that the boron isotopic composition (δ11B) and the B / Ca ratio of biogenic carbonates (mostly foraminifers) can serve as proxies for two parameters of the ocean's carbonate chemistry, rendering it possible to calculate the entire carbonate system. However, the B incorporation mechanism into marine carbonates is still not fully understood and analyses of field samples show species-specific and hydrographic effects on the B proxies complicating their application. Identifying the carbonate system parameter influencing boron incorporation is difficult due to the co-variation of pH, CO32- and B(OH)4-. To shed light on the question which parameter of the carbonate system is related to the boron incorporation, we performed culture experiments with the benthic symbiont-bearing foraminifer Amphistegina lessonii using a decoupled pH–CO32- chemistry. The determination of the δ11B and B / Ca ratios was performed simultaneously by means of a new in situ technique combining optical emission spectroscopy and laser ablation MC-ICP-MS. The boron isotopic composition in the tests gets heavier with increasing pH and B / Ca increases with increasing B(OH)4- / HCO3- of the culture media. The latter indicates that boron uptake of A. lessonii features a competition between B(OH)4- and HCO3-. Furthermore, the simultaneous determination of B / Ca and δ11B on single specimens allows for assessing the relative variability of these parameters. Among different treatments the B / Ca shows an increasing variability with increasing boron concentration in the test whereas the variability in the isotope distribution is constant.

scholarly journals Decoupled carbonate chemistry controls on the incorporation of boron into <i>Orbulina universa</i>.

2016 ◽  
Author(s):  
E. L. Howes ◽  
K. Kaczmarek ◽  
M. Raitzsch ◽  
A. Mewes ◽  
N. Bijma ◽  
...  
Keyword(s):  
Culture Media ◽  
Isotope Composition ◽  
Planktonic Foraminifera ◽  
Femtosecond Laser Ablation ◽  
Natural Systems ◽  
Surface Ocean ◽  
Constant Ph ◽  
Icp Ms ◽  
Effects Of Ph ◽  
Orbulina Universa

Abstract. In order to fully constrain paleo-carbonate systems, proxies for two out of seven parameters, plus temperature and salinity are required. The boron isotopic composition (δ11B) of planktonic foraminifera shells is a powerful tool to reconstruct changes in past surface ocean pH. As B(OH)4− is substituted into the biogenic calcite lattice in place of CO32−, it has been suggested that B/Ca ratios in biogenic calcite are a possible proxy for [CO32−]. However, differentiating between the effects of pH and [CO32−] is problematic, as they co-vary closely in natural systems, and so the major control on boron incorporation remains unclear. To deconvolve the effects of pH and [CO32−] on the B/Ca ratio and to test whether δ11B remains constant at constant pH, but under changing [CO32−] (pH 8.05 with 238, 285 and 532 µmol kg−1 CO32−) and vice versa, we decoupled pH and [CO32−] (276 ± 19.5 µmol kg−1 CO32− with pH 7.7, 7.9 and 8.05) and grew the planktonic foraminifer Orbulina universa in these manipulated culture media. Measurements of the isotope composition of boron and the B/Ca ratio were performed simultaneously using a femtosecond laser ablation system coupled to an MC ICP-MS. Results show that δ11B is controlled by pH and does not respond to changes in [CO32−]. On the other hand, the B/Ca ratio is driven by [HCO3−] independently of pH. This suggests that B/Ca ratios in foraminiferal calcite may be used as a second, independent, proxy for paleo-carbonate system reconstructions.

scholarly journals Biosynthetic Conversion of Ag+ to highly Stable Ag0 Nanoparticles by Wild Type and Cell Wall Deficient Strains of Chlamydomonas reinhardtii

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 98 ◽  
Author(s):  
Ashiqur Rahman ◽  
Shishir Kumar ◽  
Adarsh Bafana ◽  
Si Dahoumane ◽  
Clayton Jeffryes
Keyword(s):  
Cell Culture ◽  
Chlamydomonas Reinhardtii ◽  
Inductively Coupled Plasma ◽  
Culture Media ◽  
Atomic Emission ◽  
Diagnostic Tools ◽  
Inductively Coupled ◽  
Specialized Equipment ◽  
Different Strains ◽  
Over Time

In the current study, two different strains of the green, freshwater microalga Chlamydomonas reinhardtii bioreduced Ag+ to silver nanoparticles (AgNPs), which have applications in biosensors, biomaterials, and therapeutic and diagnostic tools. The bioreduction takes place in cell cultures of C. reinhardtii at ambient temperature and atmospheric pressure, thus eliminating the need for specialized equipment, harmful reducing agents or the generation of toxic byproducts. In addition to the visual changes in the cell culture, the production of AgNPs was confirmed by the characteristic surface plasmon resonance (SPR) band in the range of 415–425 nm using UV-Vis spectrophotometry and further evolution of the SPR peaks were studied by comparing the peak intensity at maximum absorbance over time. X-ray diffraction (XRD) determined that the NPs were Ag0. Micrographs from transmission electron microscopy (TEM) revealed that 97 ± 2% AgNPs were <10 nm in diameter. Ag+ to AgNP conversion was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The AgNPs were stable over time in the cell culture media, acetone, NaCl and reagent alcohol solutions. This was verified by a negligible change in the features of the SPR band after t > 300 days of storage at 4 °C.

Cellular Response of Titanium and Its Alloys as Implants

2011 ◽  
Vol 37 (4) ◽  
pp. 387-399 ◽  
Author(s):  
Rahul Bhola ◽  
Shaily M Bhola ◽  
Brajendra Mishra ◽  
Reed Ayers ◽  
David L Olson ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Cellular Response ◽  
Culture Media ◽  
Pure Titanium ◽  
Alloy System ◽  
Atomic Emission ◽  
Commercially Pure Titanium ◽  
Inductively Coupled ◽  
Potential Use

Abstract The cellular response of osteocytes to commercially pure titanium (α) and its alloys (α + β and β) has been tested in a culture media, and the results have been supplemented by analyses from various techniques such as inductively coupled plasma atomic emission spectroscopic (ICP-AES) analysis, X-ray photoemission spectroscopy (XPS), scanning electron microscopy (SEM), metallography, and electrochemical measurements. These results have been correlated with respect to the presence of various alloying elements in these alloys to qualify them for human application. The newer β alloys have been examined for their potential use as implants. These results serve as a preliminary baseline to characterize the best alloy system for a comprehensive long-term investigation.

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