scholarly journals Formation of Thiophene under Simulated Volcanic Hydrothermal Conditions on Earth—Implications for Early Life on Extraterrestrial Planets?

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 149
Author(s):  
Thomas Geisberger ◽  
Jessica Sobotta ◽  
Wolfgang Eisenreich ◽  
Claudia Huber

Thiophene was detected on Mars during the Curiosity mission in 2018. The compound was even suggested as a biomarker due to its possible origin from diagenesis or pyrolysis of biological material. In the laboratory, thiophene can be synthesized at 400 °C by reacting acetylene and hydrogen sulfide on alumina. We here show that thiophene and thiophene derivatives are also formed abiotically from acetylene and transition metal sulfides such as NiS, CoS and FeS under simulated volcanic, hydrothermal conditions on Early Earth. Exactly the same conditions were reported earlier to have yielded a plethora of organic molecules including fatty acids and other components of extant metabolism. It is therefore tempting to suggest that thiophenes from abiotic formation could indicate sites and conditions well-suited for the evolution of metabolism and potentially for the origin-of-life on extraterrestrial planets.

Author(s):  
Thomas Glonek

AbstractHow life began still eludes science life, the initial progenote in the context presented herein, being a chemical aggregate of primordial inorganic and organic molecules capable of self-replication and evolution into ever increasingly complex forms and functions.Presented is a hypothesis that a mineral scaffold generated by geological processes and containing polymerized phosphate units was present in primordial seas that provided the initiating factor responsible for the sequestration and organization of primordial life’s constituents. Unlike previous hypotheses proposing phosphates as the essential initiating factor, the key phosphate described here is not a polynucleotide or just any condensed phosphate but a large (in the range of at least 1 kilo-phosphate subunits), water soluble, cyclic metaphosphate, which is a closed loop chain of polymerized inorganic phosphate residues containing only phosphate middle groups. The chain forms an intrinsic 4-phosphate helix analogous to its structure in Na Kurrol’s salt, and as with DNA, very large metaphosphates may fold into hairpin structures. Using a Holliday-junction-like scrambling mechanism, also analogous to DNA, rings may be manipulated (increased, decreased, exchanged) easily with little to no need for additional energy, the reaction being essentially an isomerization.A literature review is presented describing findings that support the above hypothesis. Reviewed is condensed phosphate inorganic chemistry including its geological origins, biological occurrence, enzymes and their genetics through eukaryotes, polyphosphate functions, circular polynucleotides and the role of the Holliday junction, previous biogenesis hypotheses, and an Eoarchean Era timeline.


Author(s):  
Yanghong Yu ◽  
Zhongchao Zhou ◽  
Lina Xu ◽  
Yihong Ding ◽  
Guoyong Fang

Atomic layer deposition (ALD) is a nanopreparation technique for materials and is widely used in the fields of microelectronics, energy and catalysis. ALD methods for metal sulfides, such as Al2S3...


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 486
Author(s):  
Aleksandar Zivković ◽  
Michiel Somers ◽  
Eloi Camprubi ◽  
Helen E. King ◽  
Mariette Wolthers ◽  
...  

Metal sulphides constitute cheap, naturally abundant, and environmentally friendly materials for energy storage applications and chemistry. In particular, iron (II) monosulphide (FeS, mackinawite) is a material of relevance in theories of the origin of life and for heterogenous catalytic applications in the conversion of carbon dioxide (CO2) towards small organic molecules. In natural mackinawite, Fe is often substituted by other metals, however, little is known about how such substitutions alter the chemical activity of the material. Herein, the effect of Ni doping on the structural, electronic, and catalytic properties of FeS surfaces is explored via dispersion-corrected density functional theory simulations. Substitutional Ni dopants, introduced on the Fe site, are readily incorporated into the pristine matrix of FeS, in good agreement with experimental measurements. The CO2 molecule was found to undergo deactivation and partial desorption from the doped surfaces, mainly at the Ni site when compared to undoped FeS surfaces. This behaviour is attributed to the energetically lowered d-band centre position of the doped surface, as a consequence of the increased number of paired electrons originating from the Ni dopant. The reaction and activation energies of CO2 dissociation atop the doped surfaces were found to be increased when compared to pristine surfaces, thus helping to further elucidate the role Ni could have played in the reactivity of FeS. It is expected that Ni doping in other Fe-sulphides may have a similar effect, limiting the catalytic activity of these phases when this dopant is present at their surfaces.


PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0142228 ◽  
Author(s):  
Matteo M. Pusceddu ◽  
Sahar El Aidy ◽  
Fiona Crispie ◽  
Orla O’Sullivan ◽  
Paul Cotter ◽  
...  

2020 ◽  
Vol 60 (11) ◽  
pp. 1418
Author(s):  
M. A. Khan ◽  
V. T. Burggraaf ◽  
B. Thomson ◽  
P. Muir ◽  
K. Lowe ◽  
...  

Context Early life nutrition of calves influences their performance later in life. There is limited literature demonstrating the effects of rearing dairy calves in early life on milk with either exclusively forage or concentrate starter diets on metabolic and immune function and post-weaning growth and body composition on a pasture only diet. Aim This study evaluated the effects of feeding Wagyu × Holstein Friesian calves a forage starter (FS) or a concentrate starter (CS) for the first 14 weeks of rearing on rumen fermentation, blood metabolites, immune function, growth and body composition to Week 41. Methods Group-housed calves (Wagyu × Friesian, 10 calves per group, three groups per treatment) were fed milk (2 L per calf twice daily) until Week 7, then transitioned to once a day milk feeding until weaning by Week 9, with ad libitum access to either FS or CS. All calves were transferred to graze ryegrass pastures a week after transitioning to once daily milk feeding, with starter feeds removed gradually by Week 14. Thereafter, calves were reared together on pasture until Week 41. Results Solid feed intake was lower in FS than CS calves during the first 7 weeks. Total short chain fatty acids were lower, but acetate to propionate ratio and rumen pH were higher in FS than CS calves at Week 7, with no differences observed at Week 12 or 30. Plasma β-hydroxybutyrate an indicator of ketogenic ability of the rumen in developing calves was higher in FS vs CS calves at weaning. Further, FS calves had lower concentrations of circulating non-esterified fatty acids compared with CS calves at weaning. Compared with CS calves, FS calves grew slower for the first 14 weeks which was associated with lower plasma IGF-1 levels. However, FS calves had greater average daily gain after 14 weeks when on pasture and had similar plasma IGF-1 at 30 weeks and similar body weight and body composition (muscle and subcutaneous fat deposition) by Week 41 compared to CS calves. Conclusions These results indicate that offering a FS starter has better prepared calves for weaning onto pasture and potentially improved utilisation of forage post-weaning to achieve similar muscle and fat deposition and overall liveweight in both groups by 41 weeks. Implications Dairy beef calves can be successfully reared using forage as the only solid feed source without affecting their growth performance on pasture until 10 months of age. Rearing calves using forage will contribute to reducing the usage of concentrate feeds in pastoral dairy-beef production systems and provide an opportunity to fulfil the market requirements and standards for grain-free beef production.


Challenges ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 25
Author(s):  
Raphael Watt ◽  
Kimberley Parkin ◽  
David Martino

The regulation of innate immunity is substantially more ‘plastic’ than previously appreciated. Innate immune memory (manifested through trained immunity and tolerance) is a recently described epigenetic phenomenon that is a model example, with broad implications for infectious disease, allergy and autoimmunity. Training the innate immune system to combat infections and temper inappropriate responses in non-communicable diseases will likely be an area of intense research. Innate immunity is influenced by short chain fatty acids, which are the natural products of digestion by the intestinal microbiota that possess inherent histone deacetylase inhibitory properties. It therefore stands to reason that a healthy gut microbiome may well influence mucosal and systemic trained immunity via short chain fatty acids. There is a lack of data on this specific topic, and we discuss potential relationships based on available and preliminary evidence. Understanding the link between intestinal microbiome composition, capacity for short chain fatty acid production and downstream effects on innate immune memory in early life will have important implications for host immunobiology. In this review we explore the intersection between the gut microbiota, short chain fatty acids and epigenetic regulation of innate immunity with a focus on early life.


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