An automated apparatus for the simulation of prebiotic wet‒dry cycles under strictly anaerobic conditions
| العنوان: | An automated apparatus for the simulation of prebiotic wet‒dry cycles under strictly anaerobic conditions |
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| المؤلفون: | Stefan Fox, Hannes Lukas Pleyer, Henry Strasdeit |
| المصدر: | International Journal of Astrobiology. 18:60-72 |
| بيانات النشر: | Cambridge University Press (CUP), 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | Mineral, Olivine, 010504 meteorology & atmospheric sciences, Physics and Astronomy (miscellaneous), chemistry.chemical_element, Temperature cycling, engineering.material, 01 natural sciences, Decomposition, Oxygen, Atmosphere, chemistry.chemical_compound, Pyrogallol, chemistry, Chemical engineering, Space and Planetary Science, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), engineering, Clay minerals, 010303 astronomy & astrophysics, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences |
| الوصف: | Prebiotic chemical evolution on the early Earth may have been driven in part by fluctuating environments, for example wet‒dry and temperature cycling in volcanic rock pools. Here, we describe the setup, operating principle and test applications of a newly developed ‘wet‒dry apparatus’ (WDA) designed to simulate such fluctuating environments. The WDA allows adjusting the duration of the cycles, the temperature during the wet and dry phases and the organic and mineral components, which are all key parameters in wet–dry simulations. The WDA's most important features, however, are (i) that it is automated, which means that long-time experiments are possible without the need for an operator and (ii) that the virtual absence of free oxygen in the early Earth's atmosphere at ground level can be simulated. Rigorously oxygen-free conditions were achieved by passing 99.999% nitrogen gas through two alkaline pyrogallol solutions in series, prior to entering the WDA. We used three chemical systems to test the WDA: (i) the amino acid glycine in the presence and absence of clay minerals, (ii) linoleic acid (an oxygen-sensitive amphiphile) with and without the mineral olivine, and (iii) alkaline pyrogallol solution. We observed that clay minerals greatly accelerated the decomposition of glycine under wet‒dry conditions. Glycine peptides were formed as minor products. In the course of the glycine experiments, we developed a reliable gas chromatographic method to quantify the cyclic dipeptide 2,5-diketopiperazine. The decomposition of linoleic acid in wet‒dry cycles was promoted by both air and olivine. And finally, the extremely oxygen-sensitive pyrogallol solution was used as a colour indicator for residual oxygen in the WDA. The simulation facility in our laboratory currently consists of eight identical WDAs and a surrounding infrastructure. It can be made available to others who wish to perform cyclic wet–dry experiments. |
| تدمد: | 1475-3006 1473-5504 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::5d96f087e74dfbd6f126185d313710a0 https://doi.org/10.1017/s1473550418000010 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........5d96f087e74dfbd6f126185d313710a0 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14753006 14735504 |
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