scholarly journals Hexanol biosynthesis from syngas by Clostridium carboxidivorans P7 – product toxicity, temperature dependence and in situ extraction

Heliyon ◽  
2021 ◽  
pp. e07732
Author(s):  
Patrick Kottenhahn ◽  
Gabriele Philipps ◽  
Stefan Jennewein
Keyword(s):  
Temperature Dependence ◽  
In Situ Extraction ◽  
Clostridium Carboxidivorans

Temperature Dependence of Double Shockley Stacking Fault Behavior in Nitrogen-Doped 4h-Sic Studied by In-Situ Synchrotron X-Ray Topography

2020 ◽  
Author(s):  
Fumihiro Fujie ◽  
Shunta Harada ◽  
Kenji Hanada ◽  
Hiromasa Suo ◽  
Haruhiko Koizumi ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Stacking Fault ◽  
X Ray ◽  
Nitrogen Doped ◽  
Fault Behavior

scholarly journals Liquid Perfluorodecalin Application for In Situ Extraction and Enhanced Naphthoquinones Production in Arnebia euchroma Cell Suspension Cultures

2014 ◽  
Vol 172 (5) ◽  
pp. 2618-2627 ◽  
Author(s):  
Katarzyna Sykłowska-Baranek ◽  
Maciej Pilarek ◽  
Michał Cichosz ◽  
Agnieszka Pietrosiuk
Keyword(s):  
Cell Suspension ◽  
Cell Suspension Cultures ◽  
Suspension Cultures ◽  
In Situ Extraction ◽  
Arnebia Euchroma

An in-situ extraction–preconcentration method using ionic liquid-based surfactants for the determination of organic contaminants contained in marine sediments

Talanta ◽  
2012 ◽  
Vol 99 ◽  
pp. 972-983 ◽  
Author(s):  
Bárbara Delgado ◽  
Verónica Pino ◽  
Jared L. Anderson ◽  
Juan H. Ayala ◽  
Ana M. Afonso ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Marine Sediments ◽  
Organic Contaminants ◽  
In Situ Extraction ◽  
Preconcentration Method ◽  
Extraction Preconcentration

scholarly journals Влияние электромиграции на зарождение вакансионных островков на поверхности Si(100) при сублимации

2019 ◽  
Vol 53 (6) ◽  
pp. 805
Author(s):  
С.В. Ситников ◽  
Е.Е. Родякина ◽  
А.В. Латышев
Keyword(s):  
Electron Microscopy ◽  
Theoretical Model ◽  
Temperature Dependence ◽  
Effective Charge ◽  
Positive Sign ◽  
Nucleation Center ◽  
Island Nucleation ◽  
Reflection Electron Microscopy ◽  
Elementary Charge

AbstractBy means of in situ ultrahigh vacuum reflection electron microscopy, the nucleation of vacancy islands on wide terraces of the Si(100) surface is investigated. The temperature dependence of the displacement of a vacancy island nucleation center is determined in the process of heating a sample with a dc electric current. On the basis of a theoretical model, the effective electric charge of addimers is estimated in the direction across dimer rows of the surface. The effective charge has a positive sign and does not exceed 15 units of the elementary charge in the temperature range of 1020–1120°C.

scholarly journals Hexanol Biosynthesis From Syngas by Clostridium Carboxidivorans P7 - Investigation of Product Toxicity, Temperature Dependence and in Situ Extraction 

2020 ◽  
Author(s):  
Patrick Kottenhahn ◽  
Gabriele Philipps ◽  
Stefan Jennewein
Keyword(s):  
Growth Temperature ◽  
Oleyl Alcohol ◽  
Corn Oil ◽  
Fatty Acid Analysis ◽  
Limiting Factors ◽  
Major Influence ◽  
Membrane Composition ◽  
In Situ Extraction ◽  
Extraction Solvent ◽  
Clostridium Carboxidivorans

Abstract BackgroundClostridium carboxidivorans P7 converts synthesis gas (also called syngas, a mixture of CO, CO2 and H2) directly into industrially relevant alcohols (hexanol, butanol and ethanol) and their corresponding acids (caproate, butyrate and acetate). The product titers and ratios are highly dependent on fermentation parameters and the compositions of syngas as well as the growth medium. Hexanol titers produced by C. carboxidivorans P7 have recently been improved by optimizing these conditions, but little is known about the toxicity of hexanol towards Clostridium species. We hypothesized that the hexanol titers currently produced by C. carboxidivorans P7 are limited by product toxicity. ResultsWe tested our hypothesis by analyzing IC50 values for hexanol at 30 °C and 37 °C, which we determined as 17.5 ± 1.6 mM and 11.8 mM ± 0.6 mM, respectively, indicating a major influence of growth temperature on hexanol sensitivity. We found that 20 mM hexanol was acutely toxic to C. carboxidivorans P7 at 30 °C and growth was already completely inhibited in the presence of 15 mM hexanol at 37 °C. Membrane fatty acid analysis showed that the cell membrane composition of C. carboxidivorans adapted strongly to the higher growth temperature but surprisingly did not change significantly when grown in the presence of 10 mM hexanol. To avoid product toxicity during hexanol production we added oleyl alcohol as an extraction solvent. At 30 °C, addition of the solvent increased total hexanol titers nearly 2.5-fold from 10.5 to 23.9 mM. However hexanol titers decreased from 7.0 to 5.6 mM in the presence of oleyl alcohol at 37 °C. At 30 °C, the extraction phase contained large amounts of hexanol (448 ± 130 mM) and butanol (102 ± 20 mM). Values were lower at 37 °C with 101 ± 27 mM hexanol and 50 ± 6 mM butanol. Growth was not inhibited by oleyl alcohol. Biomass remained high in the presence of oleyl alcohol at 30 °C, but rapidly decreased in the absence of the solvent. At 37 °C biomass decreased even in the presence of oleyl alcohol. We tested corn oil and sunflower seed oil as potentially cheaper and more sustainable extraction solvents. While oleyl alcohol displayed the highest extraction efficiency for hexanol, total hexanol titers were similar with all solvents tested. ConclusionsBoth, product toxicity and growth temperature were identified as limiting factors during the conversion of syngas to hexanol by C. carboxidivorans P7. At 30 °C the addition of a biocompatible solvent led to detoxification and a significant increase in hexanol titers, 80% higher than highest previously reported titers. These findings help to mediate the limitation of product toxicity in hexanol production from syngas for the development of more efficient process designs and production strains.

Silicon, radium, thorium, and lead in seawater: In-situ extraction by synthetic fibre

1972 ◽  
Vol 16 (1) ◽  
pp. 84-90 ◽  
Author(s):  
S. Krishnaswami ◽  
D. Lal ◽  
B.L.K. Somayajulu ◽  
F.S. Dixon ◽  
S.A. Stonecipher ◽  
...  
Keyword(s):  
Synthetic Fibre ◽  
In Situ Extraction

Evaluating the temperature dependence of bedrock hillslope erosion in the Mont Blanc massif using in situ cosmogenic 3He-10Be-14C

2021 ◽  
Author(s):  
Donovan P. Dennis ◽  
Dirk Scherler ◽  
Samuel Niedermann ◽  
Kristina Hippe ◽  
Hella Wittmann ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Erosion Rates ◽  
Close Proximity ◽  
Order Of Magnitude ◽  
Stochastic Events ◽  
Exposure Ages ◽  
Alpine Environments ◽  
Magnitude Difference ◽  
Mont Blanc Massif

<p>The erosion of cold bedrock hillslopes in alpine environments depends not only on rates of frost weathering and accumulated rock damage, but additionally on the removal of the weathered material from the bedrock surface. In the Mont Blanc massif, steep bedrock faces with exposure ages sometimes much older than 50,000 years sit in close proximity to actively-eroding rockwalls, suggesting a more complex relationship between temperature and erosion rates than encompassed by the proposed “frost-cracking window.” Stochastic events like rockfalls and rock avalanches, despite their rarity, contribute a non-trivial proportion of the total sediment budget in alpine permafrost regions, adding to the contribution from background “steady-state” erosion. Employing a methodology based on the combination of in-situ cosmogenic nuclides <sup>3</sup>He -<sup>10</sup>Be-<sup>14</sup>C, we test the temperature-dependence of high-alpine erosion while taking into account erosional stochasticity.</p><p>From cosmogenic <sup>10</sup>Be concentrations of amalgamated samples collected on the Aiguille du Midi (3842 m a.s.l.) in the Mont Blanc massif, we find an order of magnitude difference in erosion rate across the peak’s surface. Our preliminary measured erosion rates, ranging between appx. 0.03 mm yr<sup>-1</sup> and 1.0 mm yr<sup>-1</sup>, correlate neither with modern temperature measurements from borehole thermistors, nor with our current estimates of bedrock cosmogenic <sup>3</sup>He-derived paleotemperatures. The corresponding cosmogenic <sup>14</sup>C/<sup>10</sup>Be ratios (between 1.70 and 4.0) for these erosion rates indicate that our measurements are not biased by recent stochastic rockfall events. Our current results therefore suggest that on geomorphic timescales, bedrock hillslope erosion rates are not set solely by rates of frost-cracking, but rather by the combined effects of frost-cracking and permafrost thaw-induced rockfalls. These insights are relevant both for short-term monitoring of alpine permafrost and associated geohazards under a warming climate, as well as studies of proposed “buzzsaws” operating on glacial-interglacial timescales.</p>

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