Recovering and Exploiting Aragonite and Calcite Single Crystals with Biologically Controlled Shapes from Mussel Shells

This research was performed under the Bluebio ERANET project CASEAWA (grant no.: 161B0949). This study represents partial fulfillment of the requirements for the International FishMed-PhD thesis of C.T. J.G.M acknowledges the CASEAWA project, grant no. PCI2020-112108 funded by MCIN/AEI/10.13039/501100011033 (Spain) and the EU “NextGenerationEU”/PRTR”. PCI2020-112108 is part of the ERANET Cofund BlueBio Programme supported by the European Union.Control over the shape and morphology of single crystals is a theme of great interest in fundamental science and for technological application. Many synthetic strategies to achieve this goal are inspired by biomineralization processes. Indeed, organisms are able to produce crystals with high fidelity in shape and morphology utilizing macromolecules that act as modifiers. An alternative strategy can be the recovery of crystals from biomineralization products, in this case, seashells. In particular, waste mussel shells from aquaculture are considered. They are mainly built up of single crystals of calcite fibers and aragonite tablets forming an outer and an inner layer, respectively. A simple mechanochemical treatment has been developed to separate and recover these two typologies of single crystals. The characterization of these single crystals showed peculiar properties with respect to the calcium carbonate from quarry or synthesis. We exploited these biomaterials in the water remediation field using them as substrate adsorbing dyes. We found that these substrates show a high capability of adsorption for anionic dye, such as Eosin Y, but a low capability of adsorption for cationic dyes, such as Blue Methylene. The adsorption was reversible at pH 5.6. This application represents just an example of the potential use of these biogenic single crystals. We also envision potential applications as reinforcing fillers and optical devices.Bluebio ERANET: CASEAWA 161B0949MCIN/AEI/10.13039/501100011033 (Spain) PCI2020-112108EU “NextGenerationEU”/PRTR”European Unio

Turning Seashell Waste into Electrically Conductive Particles

Biomaterials such as seashells are intriguing due to their remarkable properties, including their hierarchical structure from the nanometer to the micro- or even macroscopic scale. Transferring this nanostructure to generate nanostructured polymers can improve their electrical conductivity. Here, we present the synthesis of polypyrrole using waste seashell powder as a template to prepare a polypyrrole/CaCO3 composite material. Various synthesis parameters were optimized to produce a composite material with an electrical conductivity of 2.1 x 10(-4) +/- 3.2 x 10(-5) S/cm. This work presents the transformation of waste seashells into sustainable, electronically conductive materials and their application as an antistatic agent in polymers. The requirements of an antistatic material were met for a safety shoe sole

A non‑lethal method to assess element content in the endangered Pinna nobilis

The fan shell Pinna nobilis is the largest bivalve endemic to the Mediterranean and is actually a strongly endangered species. Due to the biological, ecological, and historical relevance of this species, the research of a non-lethal method to relate the element content in organism’s tissues and environment can provide information potentially useful to evaluate environmental pollution and organism physiological status. In this study, a screening on element concentration in the animal growing environment (seawater and sediments) and in four soft tissues (hepatopancreas, gills, mantle, and muscle), and two acellular tissues (calcite shell layer, and byssus) was performed. The comparison among these results was used to assess whether the no-lethal acellular tissue element concentration can be used to reveal the element presence in the environment and soft tissues. Elements, such as B, Ag, As, Mn, Mo, Pb, or Se, showed a possible relationship between their presence in the byssus and soft tissues. In the byssus Cr, Sb, Sn, and V have shown to be mostly related to the environment, more than the soft tissues, and might be used to draw a historical record of the exposure of the organism. The element concentration in the calcite shell layer did not relate with environmental element concentrations. Essential elements, like Cu, Fe, Ni, and Zn, were present in calcite shell layer and byssus and are likely related to their biological activity in the organism. The research also gave an overview on the presence of pollution and on the preferential intake route of the element. In summary, this study, performed on a limited number of specimens of this protected species, indicated that element concentration in the byssus can be applied as non-lethal method to monitor this endangered species and its interaction with the elements in the growing environment

A sustainable one-pot method to transform seashell waste calcium carbonate to osteoinductive hydroxyapatite micro-nanoparticles

We have developed a straightforward, one-pot, low-temperature hydrothermal method to transform oyster shell waste particles (bCCP) from the species Crassostrea gigas (Mg-calcite, 5 wt% Mg) into hydroxyapatite (HA) micro/nanoparticles. The influence of the P reagents (H3PO4, KH2PO4, and K2HPO4), P/bCCP molar ratios (0.24, 0.6, and 0.96), digestion temperatures (25-200 & DEG;C), and digestion times (1 week-2 months) on the transformation process was thoroughly investigated. At 1 week, the minimum temperature to yield the full transformation significantly reduced from 160 & DEG;C to 120 & DEG;C when using K2HPO4 instead of KH2PO4 at a P/bCCP ratio of 0.6, and even to 80 & DEG;C at a P/bCCP ratio of 0.96. The transformation took place via a dissolution-reprecipitation mechanism driven by the favorable balance between HA precipitation and bCCP dissolution, due to the lower solubility product of HA than that of calcite at any of the tested temperatures. Both the bCCP and the derived HA particles were cytocompatible for MG-63 human osteosarcoma cells and m17.ASC murine mesenchymal stem cells, and additionally, they promoted the osteogenic differentiation of m17.ASC, especially the HA particles. Because of their physicochemical features and biological compatibility, both particles could be useful osteoinductive platforms for translational applications in bone tissue engineering

Biogás: producción y aplicaciones

En el ámbito del manejo de los ambientes montanos es muy importante generar soluciones técnicas a problemas complejos, y que se lo haga localmente con pericia y destreza en la búsqueda de energías alternativas no convencionales. Al proporcionar una opción económicamente rentable que limite el uso del combustible de leña, deforestando la poca biomasa remanente que se encuentra amenazada en la Ceja de Selva peruana, la utilización del biogás, gracias a la construcción de digestores anaeróbicos que aprovechen la materia prima de desecho de las operaciones agrícolas y ganaderas, es una solución acertada para mantener el agroecosistema operando eficientemente sin aumentar el uso de combustibles fósiles y sin contribuir al calentamiento global. Son pocas las oportunidades de tener un texto tan claro, bien ilustrado y explicativo de la técnica y la teoría de uso de recursos del paisaje rural en los Andes. Me es muy grato comprobar una vez más la seriedad con que se manejan los temas de aplicación al desarrollo sustentable andino y el fructífero trabajo en equipo de los profesores de la Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas (UNTRM), liderados por los objetivos de investigación de climatología y energías alternativas junto a las aplicaciones para el desarrollo sustentable de la Ceja de Selva. Con las 178 páginas de este libro se llena un vacío dejado por similares proyectos en Honduras (la Escuela Agrícola Panamericana, Universidad Zamorano) y en Costa Rica (la Escuela de Agricultura de la Región Tropical Húmeda, Universidad EARTH) y ciertos organismos internacionales como el CATIE y el CIAT, concentrados en la franja tropical de selvas bajas. El esfuerzo liderado por el Prof. Barrena y colaboradores, trae a primera plana la necesidad de trabajar en proyectos de biocombustibles en la zona de los flancos cordilleranos y las zonas transicionales de selvas altas, como Chachapoyas, donde la topografía y la fisiografía han jugado un papel importante junto a las prácticas ancestrales de ocupación y uso de la tierra. Además, refuerza merecidamente la oferta bibliográfica técnica de consulta fácil para los usuarios del campo en Amazonas. Felicitaciones a los autores y al Instituto de Investigación para el Desarrollo Sustentable de Ceja de Selva (INDES-CES) y al Proyecto PROCICEA, que llevan a reconocer a la UNTRM como el baluarte académico para la investigación y la aplicación de alternativas ambientalmente amigables en favor de los paisajes tropandinos.Libr