Bioactive Compounds in Sarcocornia and Arthrocnemum, Two Wild Halophilic Genera from the Iberian Peninsula

(1) Background: this study describes bioactive compounds in the following halophytes: Sarcocornia (S. alpini, S. pruinosa, and S. perennis) and Arthrocnemum (A. macrostachyum). The material comes from: coastal marshes in Tinto River, Guadiana River, and some interior provinces from the Iberian Peninsula. (2) Methods: the techniques used were Folin–Ciocalteu, GC-MS, and ESI-MS/MS. (3) Results: Five phenolic acids were found in Sarcocornia: trans-cinnamic, salicylic, veratric, coumaric, and caffeic acids. In addition, in Arthronemum, ferulic acid was also detected. The obtained flavonoids were cyanidin-3-O-arabinoside, luteolin-7-glucoside, dihydroquercetin, and p-coumaroyl-glucoside. They also presented fatty acids, such as palmitic, linoleic, and oleic acids in Sarcocornia, while palmitic, linolenic, and stearic acids were the main fatty acids in A. macrostachyum. (4) Conclusions: the high diversity of the compounds identified confirms the relation between nutritional interest and salt tolerance in halophytes.

Educational Resources for EPN24 Planetary Field Analogue Sites

<p>The Europlanet 2024 Research Infrastructure (RI) provides free access to the world’s largest collection of planetary simulation and analysis facilities. The project is funded through the European Commission’s Horizon 2020 programme and runs for four years from February 2020 until January 2024. The Transnational Access (TA) programme supports all travel and local accommodation costs for European and international researchers to visit over 40 laboratory facilities and 6 Planetary Field Analogues (PFA) [1].</p> <p>As part of the education and inspiration tasks associated with Europlanet 2024 RI, we have produced classroom resources aimed at age 10-14 year olds relating the conditions found within the PFA sites to astrobiology and the habitability of Mars.</p> <p>These resources have been produced around all PFA sites:</p> <ul> <li>Rio Tinto River (Spain)</li> <li>Iceland Field Sites (Iceland)</li> <li>Danakil Depression (Ethiopia)</li> <li>Kangerlussuaq Field Site (Greenland)</li> <li>Makgadikgadi Salt Pans (Botswana)</li> <li>Andes (Argentina)</li> </ul> <p>These resources link in with common areas found in worldwide STEM curriculums, such as volcanism, pressure, pH and evaporation. To achieve this, we have filmed lab-based demonstrations and included them in a classroom lesson plan alongside teachers' notes. In addition, each lesson plan focuses on how the conditions of the PFAs could affect the habitability of Mars.</p> <p>An Italian version of the resources has been produced by EduINAF with the addition of brief video-lessons.  English versions were released on a weekly basis from mid-March through April with opportunities for training sessions to support teachers wishing to engage with these resources.</p> <p>Following studies such as Salimpour et al 2020 [2], highlighting the extent to which astronomy has been incorporated into school curriculums, we have chosen to highlight three subject areas with lower representation in high schools into our resources: physics, space exploration and astrobiology.</p> <p>As these analogue sites can be linked to more planetary bodies than just Mars, our next steps are to create similar resources based around the habitability of the icy moons of the Solar System.</p>

Natural and anthropic pollution episodes during the Late Holocene evolution of the Tinto River estuary (SW Spain)

This paper investigates the paleoenvironmental evolution of a core extracted in the middle sector of the Tinto River estuary, SW Spain, one of the most polluted areas in the world due to mining over thousands of years (>4 kyr BP) and recent industrial discharges. This evolution includes alluvial sands (>6.4 cal kyr BP), bioclastic sands and silts deposited in subtidal and intertidal channels during and after the Holocene transgression maximum (6.4-4.3 cal kyr BP), the sedimentation of clayey-sandy silts in low and high marshes during the last 2.4 kyr BP and a final anthropic filling. Three sharp peaks of pollution have been detected, representing a) a natural origin during the Holocene transgression; b) the impact of the first mining activities (~4.5 cal kyr BP); and c) the effect of industrial discharge and a new period of mining activity throughout the 19th and 20th centuries. Foraminifera, ostracods and molluscs disappeared during these last two peaks.

Bioactive Compounds in Salicornia patula Duval-Jouve: A Mediterranean Edible Euhalophyte

Many halophytes have great nutritional and functional potential, providing chemical compounds with biological properties. Salicornia patula Duval-Jouve is a common euhalophyte from saline Mediterranean territories (Spain, Portugal, France, and Italy). In the present work we quantified for the first time the bioactive compounds in S. patula (total phenolic compounds and fatty acids), from Iberian Peninsula localities: littoral-coastal Tinto River basin areas (southwest Spain, the Huelva province), and mainland continental territories (northwest and central Spain, the Valladolid and Madrid provinces). Five phenolic acids including caffeic, coumaric, veratric, salicylic, and transcinnamic have been found with differences between mainland and coastal saltmarshes. S. patula contain four flavonoids: quercetin-3-O-rutinoside, kaempferol/luteolin, apigenin 7-glucoside, and pelargonidin-3-O-rutinoside. These last two glycosylated compounds are described for the first time in this genus of Chenopodiaceae. The fatty acid profile described in S. patula stems contains palmitic, oleic, and linoleic acids in high concentrations, while stearic and long-chain fatty acids were detected in low amounts. These new findings confirm that S. patula is a valuable source of bioactive compounds from Mediterranean area.

Regulation of dissolved phosphate through incorporation into schwertmannite

<p>Phosphate is known to absorb strongly to schwertmannite (Fe<sub>8</sub>O<sub>8</sub>(OH)<sub>6</sub>(SO<sub>4</sub>)·nH<sub>2</sub>O)<sup>1</sup> and as such, schwertmannite has been proposed to limit phosphate in solution in acid mine drainage (AMD) environments. This in turn will limit phosphate availability to the micro-organisms that live in and propagate AMD<sup>2</sup>. Here we have studied sediment samples from the Rio Tinto river in Spain collected during Europlanet field area visit to verify whether phosphate can be incorporated into sulphate-rich minerals in this river. The minerals were identified using X-ray diffraction. Our analyses show that the concentration of phosphate in the river is in the nM range. Digestion of modern sediments in nitric acid followed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis indicate that sites with sulphate-rich minerals are correlated with elevated phosphate concentrations. In addition, phosphate is also retained in ancient sediments that are dominated by goethite (FeO(OH)).</p><p>We have also conducted experiments to explore the competition between Fe<sup>3+</sup>, phosphate and sulphate ions in solution as well as the effect of this on schwertmannite nucleation. UV-Vis and Raman spectroscopy demonstrate that contact ion pairs form between Fe<sup>3+</sup> and phosphate or sulphate in solution. Particularly, phosphate and sulphate compete for Fe<sup>3+ </sup>in solution consistent with predictions by the solution speciation modelling program PHREEQC. Our experiments also show that above a critical concentration, phosphate retards the nucleation of schwertmannite. As this critical concentration is above that found in Rio Tinto river fluids, phosphate is expected to have a limited role in schwertmannite precipitation, but, its concentration is regulated by its incorporation into schwertmannite and other sulphate-bearing phases in AMD systems.</p><p>References</p><p><sup>1</sup>Eskandarpour et al. 2006, Material Transactions, 1832. <sup>2</sup>Chen et al. 2015, ISME, 1579.</p>

A Spectral Comparison of Jarosites Using Techniques Relevant to the Robotic Exploration of Biosignatures on Mars

The acidic sulfate-rich waters of the Meridiani Planum region were potentially a habitable environment for iron-oxidizing bacteria on ancient Mars. If life existed in this ancient martian environment, jarosite minerals precipitating in these waters may record evidence of this biological activity. Since the Meridiani jarosite is thermodynamically stable at the martian surface, any biosignatures preserved in the jarosites may be readily available for analysis in the current surface sediments during the ongoing robotic exploration of Mars. However, thermal decomposition experiments indicate that organic compound detection of sediments containing jarosite may be challenging when using pyrolysis experiments; the instrument commonly used to assess organic matter in martian samples. So, here, we assess if the biogenicity of the Meridiani-type jarosites can be determined using complimentary spectroscopic techniques also utilized during the robotic exploration of Mars, including the upcoming ExoMars2020 rover mission. An abiotic jarosite, synthesized following established protocols, and a biological jarosite counterpart, derived from a microbial enrichment culture of Rio Tinto river sediments, were used to compare four spectroscopy techniques employed in the robotic exploration of Mars (Raman spectroscopy, mid-infrared (IR) spectroscopy, visible near-infrared reflectance (VNIR) spectroscopy and Mössbauer spectroscopy) to determine if the complimentary information obtained using these instruments can help elucidate the biological influence of Meridiani-type jarosites. Raman spectral differences might be due to the presence of unreacted reagents in the synthetic spectra and not biological contributions. Reflectance (IR/VNIR) spectra might exhibit minor organic absorption contributions, but are observed in both sample spectra, and do not represent a biosignature. Mössbauer spectra show minor differences in fit parameters that are related to crystal morphology and are unrelated to the biological (i.e., organic) component of the system. Results of this study suggest that the identification of biosignatures in Meridiani-type jarosites using the in situ robotic exploration on Mars may be possible but will be challenging. Our work provides additional insight into extraterrestrial biosignature detection and data interpretation for Mars exploration and indicates that sample return missions are likely required to unequivocally resolve the possible biogenicity of the Meridiani sediments or other jarosite-containing sediments.

Microbacter margulisiae gen. nov., sp. nov., a propionigenic bacterium isolated from sediments of an acid rock drainage pond

A novel anaerobic propionigenic bacterium, strain ADRIT, was isolated from sediment of an acid rock drainage environment (Tinto River, Spain). Cells were small (0.4–0.6×1–1.7 µm), non-motile and non-spore-forming rods. Cells possessed a Gram-negative cell-wall structure and were vancomycin-resistant. Strain ADRIT utilized yeast extract and various sugars as substrates and formed propionate, lactate and acetate as major fermentation products. The optimum growth temperature was 30 °C and the optimum pH for growth was pH 6.5, but strain ADRIT was able to grow at a pH as low as 3.0. Oxidase, indole formation, and urease and catalase activities were negative. Aesculin and gelatin were hydrolysed. The predominant cellular fatty acids of strain ADRIT were anteiso-C15 : 0 (30.3 %), iso-C15 : 0 (29.2 %) and iso-C17 : 0 3-OH (14.9 %). Major menaquinones were MK-8 (52 %) and MK-9 (48 %). The genomic DNA G+C content was 39.9 mol%. Phylogenetically, strain ADRIT was affiliated to the family Porphyromonadaceae of the phylum Bacteroidetes . The most closely related cultured species were Paludibacter propionicigenes with 16S rRNA gene sequence similarity of 87.5 % and several species of the genus Dysgonomonas (similarities of 83.5–85.4 % to the type strains). Based on the distinctive ecological, phenotypic and phylogenetic characteristics of strain ADRIT, a novel genus and species, Microbacter margulisiae gen. nov., sp. nov., is proposed. The type strain is ADRIT ( = JCM 19374T = DSM 27471T).