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Mussels often hybridise to form the Mytilus species complex comprised of M. edulis and M. galloprovincialis as the main species cultivated in Europe and, where their geographical distribution overlaps, the species M. trossulus. It has been suggested that M. trossulus have a weaker shell than the UK native M. edulis and hybridisation reduces farmed mussel yields and overall fitness. Here, we investigate the hypothesised link between species and shell weakness, employing multi-locus genotyping combined with measurements of six different phenotypes indicative of shell strength (shell thickness, flexural strength, Young’s modulus, Vicker’s hardness, fracture toughness, calcite and aragonite crystallographic orientation). Historic evidence from shell strength studies assumed species designation based on geographical origin, single locus DNA marker or allozyme genetic techniques that are limited in their ability to discern hybrid individuals. Single nucleotide polymorphic markers have now been developed with the ability to better distinguish between the species of the complex and their hybrids. Our study indicates that shell strength phenotypic traits are less associated with species than previously thought. The application of techniques outlined in this study challenges the historic influence of M. trossulus hybridisation on mussel yields and opens up potential for the environment to determine mussel shell fitness.

Vertical distributions of biogenic silica (bSi), particulate inorganic carbon (PIC) and key biomineral-forming phytoplankton indicate vertical zoning, or partitioning, during the late summer stratified period in the northeast Atlantic. Coccolithophores were generally more numerous in the surface mixed layer, whilst PIC concentrations were more homogenous with depth throughout the euphotic zone. Diatoms were notably more abundant and more diverse in the lower euphotic zone beneath the mixed layer in association with subsurface maxima in chlorophyll-a, bSi and oxygen concentrations. The four dominant coccolithophore species (Emiliania huxleyi, Gephyrocapsa muellerae, Syracosphera spp., and Rhabdosphaera clavigera) represented 78 ± 20% (range 31–100%) of the observed community across all sampled depths yet simultaneously contributed an average of only 13% to measured PIC pools. The diatom community, which was dominated by Pseudo-nitzschia spp. and by a species tentatively identified as Nanoneis longta, represented only ~1% of the bSi pool on average, with contributions increasing within the chlorophyll maximum. Despite a slow gradual deepening of the surface mixed layer in the period prior to observation, and adequate nutrient availability beneath the mixed layer, biomineral pools at this time consisted largely of detrital rather than cellular material.

Structural characterization of biologically formed materials is essential for understanding biological phenomena and their environment, and generating new bio-inspired engineering concepts. For example, nacre -- formed by mollusks in the ocean -- encodes local environmental conditions throughout its formation and has exceptional strength due to its nanoscale brick-and-mortar structure. This layered structure, comprising transparent aragonite tablets bonded with an ultra-thin organic polymer, also results in stunning interference colors. Existing methods of structural characterization of nacre rely on some form of cross-sectional analysis, such as scanning electron microscopy or polarization-dependent imaging contrast (PIC) mapping. However, these techniques are destructive and too time- and resource-intensive to analyze large sample areas. Here we present an all-optical, rapid, and non-destructive imaging technique -- hyperspectral interference tomography (HIT) -- to spatially map the structural parameters of nacre and other disordered layered materials. We combined hyperspectral imaging with optical-interference modeling to infer the mean tablet thickness and disordering of nacre layers across entire mollusk shells at various stages of development, observing a previously unknown relationship between the growth of the mollusk and tablet thickness. Our rapid, inexpensive, and nondestructive method can be readily applied to in-field studies., Main text + supplementary

Aims We propose a thorough study of the succulent halophyte Sarcocornia carinata endemic to the saline lagoons of the center of the Iberian Peninsula. We describe its elemental composition and possible seasonal variation in relation to edaphic and climatic variables, identify biominerals and analyze the distribution of salt ions and biominerals in tissue. Methods Plants and edaphic samples were collected in the four seasons of 1 year. Soils were analyzed for their pH, EC, color, and bioavailable concentration of Na+, K+, Mg2+, Ca2+, Cl−, SO42−. Soils and plants were analyzed for their total elemental and mineralogical composition. The distribution of elements and minerals in tissues was studied by scanning electron microscopy. Results Despite the variations observed in the edaphic and climatic variables, the variables studied in the plants varied slightly throughout the year. In the plants, Mg was the element that reflected climatic changes the most, while the K and Ca concentrations did not vary. Salty precipitates and crystallizations were distributed mainly in the epidermis, water storage parenchyma, cortex, and vascular vessels. Several crystals observed were compatible with halite, gypsum, glushinskite and weddellite. Conclusions The study corroborates that inland S. carinata behaves in the same way as other littoral succulent euhalophytes and reinforces the hypothesis that the concentration of elements and quantitative abundance pattern depend largely on the main adaptation mechanisms of halophytes. pre-print 374 KB

Wasps are a group of social insects that build a house, known as a nest, from locally available building materials cemented by their saliva and secretions. Similar to termite nests, there could be many beneficiary bacteria present in their house that can play an important part in maintaining sustainability in soil ecosystems. Thus, the present study was initiated with a physico-chemical characterization of wasp nests collected from residential and forest zones, followed by unconfined compressive strength (UCS) and X-ray diffraction (XRD) analysis to identify major associated minerals. Further, MiSeq Illumina sequencing of the 16S rRNA gene (V3&ndash, V4 regions) was carried out to analyze complete bacterial community composition of wasp nests. The resulting data showed a dominance of Actinobacteria followed by Proteobacteria in both nests. Kaistobacter and Phycicoccus were the dominant genera in each type of wasp nest. It was concluded that wasp nests are an abundant source to isolate bacteria that can potentially be helpful in soil biogeochemical cycling and fertility, antibiotics production and bioremediation.

This study aimed to evaluate the potential of clays from the State of Paraíba to be used for medicinal, therapeutic and aesthetic treatments. The samples were characterized by X-ray diffraction, X-ray fluorescence chemical composition, thermogravimetry, differential thermal analysis, laser diffraction granulometric analysis, cation exchange capacity, and antimicrobial activity. Based on the study, it was concluded that the clays from the State of Paraíba had properties similar to those of commercial clay. The antimicrobial evaluation revealed that the samples showed no activity against the three bacterial strains of clinical interest: Staphylococcus epidermidis ATCC 12 228, Staphylococcus aureus ATCC 25 923, and Escherichia coli ATCC 25 922. Finally, it was concluded that the clays studied have the potential for technological applications in medicinal, therapeutic, and aesthetic treatments, and as raw material for obtaining biomaterials, due to their stability and biological safety. Resumo Este trabalho teve como objetivo avaliar a potencialidade das argilas do estado da Paraíba, visando suas aplicações em tratamentos medicinais, terapêuticos e estéticos. As amostras das argilas foram caracterizadas pelas técnicas de difração de raios X, composição química por fluorescência de raios X, termogravimetria, análise térmica diferencial, análise granulométrica por difração a laser, capacidade de troca catiônica e atividade antimicrobiana. Com base no estudo, concluiu-se que as argilas do estado da Paraíba apresentaram propriedades similares à argila comercial. A avaliação antimicrobiana revelou que as amostras não apresentaram atividade frente a três cepas bacterianas de interesse clínico: Staphylococcus epidermidis ATCC 12 228, Staphylococcus aureus ATCC 25 923 e Escherichia coli ATCC 25 922. Por fim conclui-se que as argilas estudadas possuem potencial tecnológico para aplicações em tratamentos medicinais, terapêuticos, estéticos e como matéria-prima para obtenção de biomateriais, em virtude da sua estabilidade e segurança biológica.

Ten distinct microstructures occur in fossil serpulids and serpulid tubes can contain several layers with different microstructures. Diversity and complexity of serpulid skeletal structures has greatly increased throughout their evolution. In general, Cenozoic serpulid skeletal structures are better preserved than Mesozoic ones. The first complex serpulid microstructures comparable to those of complex structures of molluscs appeared in the Eocene. The evolution of serpulid tube microstructures can be explained by the importance of calcareous tubes for serpulids as protection against predators and environmental disturbances. Both fossil cirratulids and sabellids are single layered and have only spherulitic prismatic tube microstructures. Microstructures of sabellids and cirratulids have not evolved since the appearance of calcareous species in the Jurassic and Oligocene, respectively. The lack of evolution in sabellids and cirratulids may result from the unimportance of biomineralization for these groups as only few species of sabellids and cirratulids have ever built calcareous tubes.

The shell of the bivalve mollusc Pinctada maxima is composed of the calcium carbonate polymorphs calcite and aragonite (nacre). Mother‐of‐pearl, or nacre, induces vertebrate cells to undergo osteogenesis and has good osteointegrative qualities in vivo. The calcite counterpart, however, is less researched in terms of the response of vertebrate cells. This study shows that isolation of calcite surface topography from the inherent chemistry allows viable long‐term culture of bone marrow derived mesenchymal stem cells (MSCs). Self‐renewal is evident from the increased gene expression of the self‐renewal markers CD63, CD166, and CD271 indicating that cells cultured on the calcite topography maintain their stem cell phenotype. MSCs also retain their multipotency and can undergo successful differentiation into osteoblasts and adipocytes. When directed to adipogenesis, MSCs cultured on prism replicas are more amenable to differentiation than MSCs cultured on tissue culture polystyrene indicating a higher degree of plasticity in MSCs growing on calcite P. maxima prismatic topography. The study highlights the potential of the calcite topography of P. maxima as a biomimetic design for supporting expansion of MSC populations in vitro, which is of fundamental importance if it meets the demands for autologous MSCs for therapeutic use.

Microbe-mineral interactions in caves can lead to secondary mineral formations such as speleothems, moonmilk etc. In the present review, we provide a summary of geomicrobiological work done so far in some Indian caves. Microbially induced mineralization is documented in cave ecosystems and microbial metabolisms help in mineral formations either through direct/active or indirect/passive processes. Laboratory based experiments conducted on speleothems from Sahastradhara caves (Dehradun); Borra Cave (Andhra Pradesh); Krem Phyllut, Krem Mawsmai, Krem Mawmluh and Rongai Dobhakol (Meghalaya) have clearly demonstrated that bacterial strains isolated from these caves have the capability to precipitate minerals under controlled conditions.

Chemolithotrophic iron-oxidizing bacteria (FeOB) could theoretically inhabit any environment where Fe(II) and O2 (or nitrate) coexist. Until recently, marine Fe-oxidizing Zetaproteobacteria had primarily been observed in benthic and subsurface settings, but not redox-stratified water columns. This may be due to the challenges that a pelagic lifestyle would pose for Zetaproteobacteria, given low Fe(II) concentrations in modern marine waters and the possibility that Fe oxyhydroxide biominerals could cause cells to sink. However, we recently cultivated Zetaproteobacteria from the Chesapeake Bay oxic–anoxic transition zone, suggesting that they can survive and contribute to biogeochemical cycling in a stratified estuary. Here we describe the isolation, characterization, and genomes of two new species, Mariprofundus aestuarium CP-5 and Mariprofundus ferrinatatus CP-8, which are the first Zetaproteobacteria isolates from a pelagic environment. We looked for adaptations enabling strains CP-5 and CP-8 to overcome the challenges of living in a low Fe redoxcline with frequent O2 fluctuations due to tidal mixing. We found that the CP strains produce distinctive dreadlock-like Fe oxyhydroxide structures that are easily shed, which would help cells maintain suspension in the water column. These oxides are by-products of Fe(II) oxidation, likely catalyzed by the putative Fe(II) oxidase encoded by the cyc2 gene, present in both CP-5 and CP-8 genomes; the consistent presence of cyc2 in all microaerophilic FeOB and other FeOB genomes supports its putative role in Fe(II) oxidation. The CP strains also have two gene clusters associated with biofilm formation (Wsp system and the Widespread Colonization Island) that are absent or rare in other Zetaproteobacteria. We propose that biofilm formation enables the CP strains to attach to FeS particles and form flocs, an advantageous strategy for scavenging Fe(II) and developing low [O2] microenvironments within more oxygenated waters. However, the CP strains appear to be adapted to somewhat higher concentrations of O2, as indicated by the presence of genes encoding aa3-type cytochrome c oxidases, but not the cbb3-type found in all other Zetaproteobacteria isolate genomes. Overall, our results reveal adaptations for life in a physically dynamic, low Fe(II) water column, suggesting that niche-specific strategies can enable Zetaproteobacteria to live in any environment with Fe(II).

Dolomite (MgCa(CO3)2) is an important petroleum reservoir rock mineral common in ancient sedimentary rocks which is infrequently found in modern environments. The mechanism of dolomite formation remains poorly understood, although recent research has focused on the contribution of microbial processes. Sabkha is the Arabic term for saline mudflats occurring in regions characterized by extreme environmental conditions (high temperature, salinity, light intensity, and aridity), where diverse halophilic and extremophilic microorganisms are found. The dynamic evaporitic systems characteristic of sabkhas are crucial for the precipitation of minerals and a role for microorganisms in sabkhas in the process of mineralization has been proposed. In this study the Dohat Faishakh Sabkha in Qatar was investigated for evidence of the role for aerobic bacteria in mediating the formation of high magnesium carbonates and dolomite, two minerals that commonly occur in the sabkha sediments. Twenty-nine strains of aerobic microbes were obtained through inoculation on agar plates from two different cores sampled from the sabkha and identified by 16S rRNA gene sequencing as belonging to the genera Bacillus, Salinivibrio, Staphylococcus and, primarily, Virgibacillus. All strains examined caused the pH of an artificial growth medium to increase from 7 to 8.5; however, not all were capable of mediating mineral formation. Only Salinivibrio and Virgibacillus spp. isolates mediated the formation of detectable solid phases within the agar plates. Light microscopy, scanning electron microscopy energy dispersive X-ray (SEM/EDX), and X-ray diffraction (XRD) analyses indicate that the solid phase produced in the presence of these bacterial strains is MgCa(CO3)2 with a MgCO3 mol% varying from 0 to 40%. The results of these laboratory experiments suggested that, in the Dohat Faishakh Sabkha, aerobic bacteria may contribute in the formation of very high Mg calcite, a mineral that is considered the precursor of ordered dolomite., Frontiers in Environmental Science, 5, ISSN:2296-665X

Species of Haliotis (abalone) show high variety in structure and mineralogy of the shell. One of the European species (Haliotis tuberculata) in particular has an unusual shell structure in which calcite and aragonite coexist at a microscale with small patches of aragonite embedded in larger calcitic zones. A detailed examination of the boundary between calcite and aragonite using analytical microscopies shows that the organic contents of calcite and aragonite differ. Moreover, changes in the chemical composition of the two minerals seem to be gradual and define a micrometric zone of transition between the two main layers. A similar transition zone has been observed between the layers in more classical and regularly structured mollusk shells. The imbrication of microscopic patches of aragonite within a calcitic zone suggests the occurrence of very fast physiological changes in these taxa.

International audience; To assess the effect of polymeric substances on the biomineralization and stabilization of green rust (GR), the effect of two organic polymers on the transformation of lepidocrocite (γ-FeOOH) to GR vs. magnetite in presence of Shewanella putrefaciens was investigated. These two polymers, generally used as flocculants, are polyacrylic acid (PAA), which bears negatively charged carboxylic groups at neutral pH and is expected to react with cationic hydrolyzed iron species, and polyacrylamide (PAM), which is a neutral polymer that may develop hydrogen bonds with iron nanocolloids. The bioreduction of lepidocrocite by S. putrefaciens was performed under conditions known to yield either magnetite or GR. Each operational condition of interest was investigated with various polymer concentrations from 0.6 to 60 mg g−1 Fe (10 to 1000 mg l−1). The final product was characterized using X-ray diffraction and electronic microscopy. The results showed that the formation of GR is favored, with respect to magnetite, to a lesser extent with PAM than with PAA. These results indicated that polymers influence the chemical stability of GR and/or guide the route of biomineralization. Polymer properties, in addition to silica and phosphate concentrations, are then critical parameters that control the secondary iron mineral biomineralization from iron-reducing bacteria.

Plant biominerals are not always well characterized, although this information is important for plant physiology and can be useful for taxonomic purposes. In this work, fresh plant material of seven wild neotropical species of genus Canna, C. ascendens, C. coccinea, C. indica, C. glauca, C. plurituberosa, C. variegatifolia and C. fuchsina sp. ined., taken from different habitats, were studied to characterize the biominerals in their internal tissues. For the first time, samples from primary and secondary veins of leaves were investigated by means of infrared spectroscopy, complemented with X-ray powder diffractometry and scanning electron microscopy. The spectroscopic results, supported by X-ray powder diffractometry, suggest that the calcium oxalate is present in the form of whewellite (CaC2O4×H2O) in all the investigated samples. It is interesting to emphasize that all IR spectra obtained were strongly similar in all species studied, thus indicating an identical chemical composition in terms of the biominerals found. In this sense, the results suggest that the species of Canna show similar ability to produce biogenic silica and produce an identical type of calcium oxalate within their tissues. These results can be an additional trait to support the relationship among the families of Zingiberales. Rev. Biol. Trop. 58 (4): 1507-1515. Epub 2010 December 01.Los biominerales de las plantas no siempre han sido bien caracterizados aunque esta información es importante en fisiología vegetal y puede ser de utilidad para fines taxonómicos. En este trabajo se estudió material vegetal fresco de siete especies silvestres neotropicales: Canna, C. ascendens, C. coccinea, C. indica, C. glauca, C. plurituberosa, C. variegatifolia and C. fuchsina sp. ined., provenientes de diferentes localidades, con el fin de caracterizar los biominerales presentes en sus tejidos foliares internos. Por vez primera, muestras de venas primarias (ejes foliares) y secundarias de hojas de estas especies se investigaron por medio de espectroscopia de infarrojo, complementada con estudios por difracción de rayos X de polvos y microscopía electrónica de barrido. Los resultados indicaron la presencia de ópalo (sílice biogénica) y oxalato de calcio en los tejidos vegetales analizados. Además, se determinó que el oxalato de calcio está presente en forma de whewellita (CaC2O4×H2O), información nueva para el género. Tanto el ópalo como la whewellita están presentes en todas las especies analizadas, que representan aproximadamente un tercio de las especies silvestres del género. La capacidad de biomineralizar SiO2 en forma de ópalo en especies de Canna de diversos ambientes resulta también un rasgo altamente sugerente para futuros estudios.

INTRODUÇÃO: Otólitos são concrescências calcárias presentes no ouvido interno de peixes. Por serem ricos em minerais considerados essenciais ao processo de mineralização óssea sobre uma matriz proteica (otolina), sugere-se que otólitos poderiam funcionar como biominerais. OBJETIVO: Avaliar a capacidade de regeneração de defeitos ósseos tratados com preparado gelatinoso estéril de otólitos. MATERIAL E MÉTODO: O experimento foi realizado com 20 ratos Wistar, distribuídos aleatoriamente em dois grupos, nos quais se realizou defeito ósseo na tíbia, sendo o grupo 1 (G1) experimental, cujas lojas ósseas foram preenchidas com preparado de otólitos, e o grupo 2 (G2) controle, cujas lojas ósseas não receberam tratamento adicional. Os animais foram sacrificados 14 dias após os procedimentos cirúrgicos; as tíbias foram removidas, fixadas em formalina a 10%, descalcificadas em ácido nítrico a 5% e processadas histologicamente. Antes dos sacrifícios, foram coletadas amostras sanguíneas para avaliação das dosagens séricas de cálcio (Ca) e fosfatase alcalina (Alkp). RESULTADOS: As secções histológicas revelaram que o trabeculado ósseo neoformado mostrou-se mais denso e com atividade osteorreabsortiva periosteal menos conspícua no grupo experimental. Entretanto, não demonstraram diferenças estatisticamente significativas na área de neoformação óssea entre G1 (1,9 ± 0,3 mm²) e G2 (1,5 ± 0,4 mm²) (p = 0,0617). Os parâmetros bioquímicos (Ca e Alkp) apresentaram-se dentro dos limites de normalidade. DISCUSSÃO/CONCLUSÃO: Os dados sugerem que os otólitos podem desempenhar papel adjuvante na dinâmica da regeneração óssea. INTRODUCTION: Otoliths are calcareous concrescences present in the inner ear of fishes. Since they are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin), it has been suggested that otoliths may work as biominerals. OBJECTIVE: The objective in this study was to analyze the regeneration capacity of bone defects treated with sterile gelatinous otolith preparation. MATERIAL AND METHOD: The experiment was performed with 20 Wistar rats randomized into two groups, in which a bone defect was inflicted in the tibia. In group 1 (experimental), bone cavities were filled with otoliths. In group 2 (control), bone cavities did not receive any additional treatment. The animals were sacrificed 14 days after surgical procedures. The tibias were removed, fixed in formalin at 10%, decalcified in nitric acid at 5% and histologically processed. Before sacrifice, blood samples were collected to evaluate serum dosage of calcium (Ca2+) and alkaline phosphatase (Alkp). RESULTS: Histological sections revealed that the newly formed trabecular bone was denser and the periosteal reabsorptive activity was less conspicuous in the experimental group. However, there was no statistically significant difference in the area of bone formation between G1 (1.9 ± 0.3 mm²) and G2 (1.5 ± 0.4 mm²) (p = 0.0617). Biochemical (Ca2+ and Alkp) parameters were within normal range. DISCUSSION/CONCLUSION: These data suggest that otoliths may be an adjuvant to the dynamics of bone regeneration.

Calcium oxalate druses were isolated from the stems and leaves of six Pereskioideae family members and investigated by infrared spectroscopy, showing that in all samples the biomineral was present in the form of whewellite, CaC2O4 · H2O. As Pereskia is thought to represent the “ancestral” condition of the leafl ess stem-succulent cacti, these results suggest that the biomineralization of calcium oxalate in Cactaceae represents a primitive characteristic of the group and also support a close genetic relationship between Pereskia and Opuntia., Publicado on line en 2014., Centro de Química Inorgánica

International audience; Due to its particular mode of growth, the coral skeleton provides a natural model for evaluating the successive stages of diagenesis in a still-living organism. The spatial distribution of skeletal organic matrices and their early diagenesis have been investigated in a scleractinian skeleton with in situ micron-scale analyses by Raman Microspectroscopy. Results indicate that the decay of the organic matrices occurs within a few years. We suggest that the gradual deterioration of the skeletal organic matrices is a keymechanism driving earliest diagenesis in coral skeletons and represents the starting-point of the process of fossilization.

This paper presents an overview of the study of the ultrastructure of biogenic inorganic solids (biominerals) using high resolution transmission electron microscopy (HRTEM). A range of biominerals have been studied including iron oxides, calcium phosphates, calcium carbonates and silica. The studies have revealed information concerning the structural complexity of these materials and have identified crystallographic order and disorder at the nanometre level. In addition, the results have aided the elucidation of the mechanisms of nucleation and growth of biogenic minerals.