Carbonate Biomineralization Research Articles

Role of B. Licheniformis in bio mineralization of calcium carbonate and its biological applications

Bio mineralization is a significant process carried out by living organisms in which minerals are produced through the hardening of biological tissues. Herein, the current study focus on calcium carbonate precipitation, as part of bio mineralization, to be used in applications for CO2 sequestration, material technology, and other fields. A strain B. licheniformis, isolated from marine water, was investigated for its ability to produce urease and induce calcium carbonate precipitation in a metabolic process. It was discovered that B. licheniformis, resisted high concentrations of urea up to 60 g/L. In order to optimize the calcification process of B. licheniformis, the Calcium carbonate precipitation media is used respectively, pH of 10, and culture time of 96 h. Using X-ray diffraction and Scanning Electron Microscopy analysis, the calcium carbonate polymorphs produced by B. licheniformis, were proven to be mainly calcite. The results of this research provide evidence that B. licheniformis can biologically induce calcification and suggest that B. licheniformis may play a potential role in the synthesis of new bio minerals and in bioremediation or bio recovery.

The Combined Effects of Sr(II) and Poly(Acrylic Acid) on the Morphology of Calcite.

Biomineralization of calcium carbonate has interesting characteristics of intricate morphology formation with controlled crystal polymorphs. In particular, modification of calcite morphology with diverse additives has been the focus of many biomimetic and bioinspired studies. The possible role of strontium ions in enhancing the morphology-modifying ability of macromolecules was investigated. In the present study, concentrations of strontium ions were comparable to that in seawater, and anionic poly(acrylic acid) and cationic poly(ethylene imine) were used as model macromolecules. When strontium ions were combined with anionic poly(acrylic acid), new types of calcite surfaces, most likely {hk0}, appeared to drastically change the morphology of the crystals, which was not observed with cationic poly(ethylene imine). This behavior of strontium ions was quite similar to that of magnesium ions, which is intriguing because both ions are available from seawater to be utilized during biomineralization.

Biomineralization by particle attachment in early animals

Crystallization by particle attachment (CPA) of amorphous precursors has been demonstrated in modern biomineralized skeletons across a broad phylogenetic range of animals. Precisely the same precursors, hydrated (ACC-H2O) and anhydrous calcium carbonate (ACC), have been observed spectromicroscopically in echinoderms, mollusks, and cnidarians, phyla drawn from the 3 major clades of eumetazoans. Scanning electron microscopy (SEM) here also shows evidence of CPA in tunicate chordates. This is surprising, as species in these clades have no common ancestor that formed a mineralized skeleton and appear to have evolved carbonate biomineralization independently millions of years after their late Neoproterozoic divergence. Here we correlate the occurrence of CPA from ACC precursor particles with nanoparticulate fabric and then use the latter to investigate the antiquity of the former. SEM images of early biominerals from Ediacaran and Cambrian shelly fossils show that these early calcifiers used attachment of ACC particles to form their biominerals. The convergent evolution of biomineral CPA may have been dictated by the same thermodynamics and kinetics as we observe today.

Electron backscatter diffraction (EBSD) analysis of maniraptoran eggshells with important implications for microstructural and taphonomic interpretations

AbstractElectron backscatter diffraction (EBSD) is a useful tool for gathering crystallographic information from carbonate biominerals because it maps out the orientation of crystal grains very precisely. EBSD has become popular in invertebrate palaeontology but its application in vertebrate palaeontology remains limited. However, the study of fossil eggshells is a field where EBSD has wide potential applicability and provides a quantitative approach to fossil eggshell research as well as new qualitative data. Here we analyse fossil and extant maniraptoran dinosaur eggshells using EBSD analysis emphasizing four different aspects. The mapping imaging clarifies previously ambiguous characters such as squamatic ultrastructure and allows a more objective evaluation of avian and non‐avian maniraptoran eggshell. In particular, our results imply that the presence of an external zone in the manirpatoran eggshell is not diagnostic of avian eggshell. EBSD analysis can be also used for differentiating true pore canals from cracks in the eggshell radial section, thereby determining the biological genuineness or otherwise of a pore‐like structure. Finally, the misorientation angle distribution of the material shows a clear dichotomy that may reflect reproductive brooding strategy, although further studies on contact incubation of palaeognaths and neognaths are needed to confirm this.

Biomineralization of carbonates induced by the fungi Paecilomyces inflatus and Plectosphaerella cucumerina

The biomineralization of carbonate minerals, such as calcite, vaterite, aragonite, siderite, and dolomite, is an intensively studied phenomenon due to its practical application. This work aimed at studying carbonate-precipitating fungi isolated from a calthemite straw stalactite growing from a concrete ceiling of a building. The isolates were molecularly identified as the ascomycetes Paecilomyces inflatus and Plectosphaerella cucumerina. After 6 months of laboratory incubation, P. inflatus and P. cucumerina showed rates of CaCO3 precipitation of 15.68 and 16.28 g L−1, respectively. A diffuse network of fungal hyphae, clothed with micrometric and well-formed crystals, was observed by SEM. XRD analysis of the precipitated crystals showed that vaterite and calcite crystals were associated with P. inflatus hyphae, whereas pure calcite crystals were observed in the presence of P. cucumerina. P. inflatus and P. cucumerina grew within pH ranges of 3–11 and 4 to 12, respectively. Furthermore, both microorganisms were able to precipitate pyromorphite and hydrocerussite when cultivated in broth amended with Pb2+. Such strains seem to represent particularly suitable candidates for concrete healing, bioremediation processes and soil and sand consolidation. To our best knowledge, this is the first time that P. inflatus and P. cucumerina are described as fungal species capable of biomineralizing carbonates.

Composite Materials Design: Biomineralization Proteins and the Guided Assembly and Organization of Biomineral Nanoparticles.

There has been much discussion of the role of proteins in the calcium carbonate biomineralization process, particularly with regard to nucleation, amorphous stabilization/transformation, and polymorph selection. However, there has been little if any discussion of the potential role that proteins might play in another important process: the guided assembly and organization of mineral nanoparticles into higher-ordered structures such as mesocrystals. This review discusses particle attachment theory and recent evidence of mineral-associated proteins forming hydrogels that assemble and organize mineral clusters into crystalline phase. From this discussion we postulate a mechanism by which biomineralization protein hydrogel aggregation assists in mineral nanoparticle assembly and organization within calcium carbonate skeletal elements and discuss potentials ways for harnessing this process in materials design.

Molecular dynamics simulation of protein-mediated biomineralization of amorphous calcium carbonate.

The protein-mediated biomineralization of calcium carbonate (CaCO3) in living organisms is primarily governed by critical interactions between the charged amino acids of the protein, solvent, calcium (Ca2+) and carbonate (CO32−) ions. The present article investigates the molecular mechanism of lysozyme-mediated nucleation of amorphous calcium carbonate (ACC) using molecular dynamics and metadynamics simulations. The results reveal that, by acting as nucleation sites, the positively charged side chains of surface-exposed arginine residues form hydrogen bonds with carbonates and promote aggregation of ions around them leading to the formation and growth of ACC on the protein surface. The newly formed ACC patches were found to be less hydrated due to ion aggregation-induced expulsion of water from the nucleation sites. Despite favorable electrostatic interactions of the negatively charged side chains of aspartate and glutamate with calcium ions, these residues contribute minimally to the growth of ACC on protein surface. The activation barrier for the growth of partially hydrated ACC patches on lysozymes was determined from the free energy profiles obtained from metadynamics simulations.

Application of Microbial Carbonate Biomineralization in Biotechnologies of Building Materials Creation and Restoration: Analysis of the State and Prospects of Development

Application of Microbial Carbonate Biomineralization in Biotechnologies of Building Materials Creation and Restoration: Analysis of the State and Prospects of Development

Development of Phosphatized Calcium Carbonate Biominerals as Bioactive Bone Graft Substitute Materials, Part I: Incorporation of Magnesium and Strontium Ions.

Synthetic materials based on calcium phosphate (CaP) are frequently used as bone graft substitutes when natural bone grafts are not available or not suitable. Chemical similarity to bone guarantees the biocompatibility of synthetic CaP materials, whereas macroporosity enables their integration into the natural bone tissue. To restore optimum mechanical performance after the grafting procedure, gradual resorption of CaP implants and simultaneous replacement by natural bone is desirable. Mg and Sr ions released from implants support osteointegration by stimulating bone formation. Furthermore, Sr ions counteract osteoporotic bone loss and reduce the probability of related fractures. The present study aimed at developing porous Ca carbonate biominerals into novel CaP-based, bioactive bone implant materials. Macroporous Ca carbonate biominerals, specifically skeletons of corals (aragonite) and sea urchins (Mg-substituted calcite), were hydrothermally converted into pseudomorphic CaP materials with their natural porosity preserved. Sr ions were introduced to the mineral replacement reactions by temporarily stabilizing them in the hydrothermal phosphate solutions as Sr-EDTA complexes. In this reaction system, Na, Mg, and Sr ions favored the formation of correspondingly substituted β-tricalcium phosphate over hydroxyapatite. Upon dissolution, the incorporated functional ions became released, endowing these CaP materials with bioactive and potentially osteoporotic properties.

Development of Phosphatized Calcium Carbonate Biominerals as Bioactive Bone Graft Substitute Materials, Part II: Functionalization with Antibacterial Silver Ions

Porous calcium phosphate (CaP) materials as bone graft substitutes can be prepared from Ca carbonate biomineral structures by hydrothermal conversion into pseudomorphic CaP scaffolds. The present study aims at furnishing such phosphatized Ca carbonate biomineral (PCCB) materials with antibacterial Ag ions in order to avoid perisurgical wound infections. Prior to this study, PCCB materials with Mg and/or Sr ions incorporated for stimulating bone formation were prepared from coral skeletons and sea urchin spines as starting materials. The porous PCCB materials were treated with aqueous solutions of Ag nitrate with concentrations of 10 or 100 mmol/L, resulting in the formation of Ag phosphate nanoparticles on the sample surfaces through a replacement reaction. The materials were characterized using scanning electron microscopy (SEM) energy-dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD). In contact with Ringer`s solution, the Ag phosphate nanoparticles dissolved and released Ag ions with concentrations up to 0.51 mg/L, as shown by atomic absorption spectroscopy (AAS) analyses. In tests against Pseudomonas aeruginosa and Staphylococcus aureus on agar plates, antibacterial properties were similar for both types of Ag-modified PCCB materials. Concerning the antibacterial performance, the treatment with AgNO3 solutions with 10 mmol/L was almost as effective as with 100 mmol/L.

Biomineralization of calcium carbonate controlled by biomolecules produced by Bacillus sp.

In this study, culture supernatant of Bacillus subtilis KP7 growing on liquid LB medium consisted of 2 % of molasses was used for calcium carbonate synthesis. Synthesis of the calcium carbonate structures was performed in a reactor by mixing CaCl2 and Na2CO3 solutions at 25°C. The calcium carbonate particles were characterized by optical microscopy, FTIR and XRD analysis. In addition, the size distribution and the value of zeta potential were determined. It was observed that properties of obtained calcium carbonate depend on the supernatant amount. The smallest crystals of pure calcite with disordered structure were obtained when the concentration of the cell-free supernatant was 5 % (v/v).

Biomineralization of Calcium Phosphate and Calcium Carbonate within Iridescent Chitosan/Iota-Carrageenan Multilayered Films.

This work systematically explores the biomineralization of calcium phosphate (CaP) and carbonate (CaCO3) within chitosan/iota-carrageenan multilayer films. Multilayer films of chitosan and iota-carrageenan (up to 128-coupled layers) were prepared on glass substrates by a layer-by-layer dip-coating technique. Cryo-scanning electron microscopy revealed dense interfaces between the chitosan and iota-carrageenan layers with thicknesses in the range 250 and 350 nm in the hydrated state, accounting for the iridescent nature of multilayer films when wet. Immersion of the multilayered films in simulated body fluid or simulated seawater at 25 °C resulted in the mineralization of CaP and CaCO3, respectively, at the interfaces between the biopolymer layers and modified the iridescence of the films. Lamellar scattering features in small-angle neutron scattering measurements of the mineralized films provided evidence of the localized mineralization. Further evidence of this was found through the lack of change in the dynamic and static correlation lengths of the polymer networks within the bulk phase of the chitosan and iota-carrageenan layers. CaP mineralization occurred to a greater extent than CaCO3 mineralization within the films, evidenced by the higher lamellar density and greater rigidity of the CaP-mineralized films. Results provide valuable new insights into CaP and CaCO3 biomineralization in biopolymer networks.

Carbonate Biomineralization Using Speleothems and Sediments from Baekasan Acheon Cave (Limestone Cave) in Hwasun-gun, Jeollanam-do, South Korea

Carbonate Biomineralization Using Speleothems and Sediments from Baekasan Acheon Cave (Limestone Cave) in Hwasun-gun, Jeollanam-do, South Korea

Shape-preserving transformation of carbonate minerals into lead halide perovskite semiconductors based on ion exchange/insertion reactions.

Biological and bio-inspired mineralization processes yield a variety of three-dimensional structures with relevance for fields such as photonics, electronics and photovoltaics. However, these processes are only compatible with specific material compositions, often carbonate salts, thereby hampering widespread applications. Here we present a strategy to convert a wide range of metal carbonate structures into lead halide perovskite semiconductors with tunable bandgaps, while preserving the 3D shape. First, we introduce lead ions by cation exchange. Second, we use carbonate as a leaving group, facilitating anion exchange with halide, which is followed rapidly by methylammonium insertion to form the perovskite. As proof of principle, pre-programmed carbonate salt shapes such as vases, coral-like forms and helices are transformed into perovskites while preserving the morphology and crystallinity of the initial micro-architectures. This approach also readily converts calcium carbonate biominerals into semiconductors, furnishing biological and programmable synthetic shapes with the performance of artificial compositions such as perovskite-based semiconductors.

Preliminary Data on the Nanoscale Chemical Characterization of the Inter-Crystalline Organic Matrix of a Calcium Carbonate Biomineral

Chemical signatures of carbonate biominerals are important for understanding biomineral formation, and are a subject of great interest in geosciences for applications in paleoclimatology and paleoceanography. A prominent unknown factor is the chemistry of organic matrices, in particular that of the inter-crystalline fraction. Here, we use atom probe tomography (APT) for the nanoscale chemical characterization of the mineral-organic interface in calcite from mussel shells. Our findings indicate that the quality of APT bulk chemistry results is highly dependent on sample preparation, yet data on biogenic calcite could be geochemically interpreted with confidence. Three-dimensional (3D) reconstructions of calcite tip specimens show the presence of organic matrix domains, characterized by the depletion of cations but enrichment in oxygen and carbon, and with at least 1% atomic increase in 16O relative to the surrounding mineral phase. This is the first relative, in-situ quantification of the chemical composition of the inter-crystalline organic matrix (IOM) for a carbonate biomineral, with implications for a better understanding of vital effects, proxy calibration, and the formation of these biocarbonates. Overall, our findings demonstrate the potential of nanoscale characterization of biominerals and their abiogenic counterparts to further advance our understanding of their chemistry.

Preparation and characterization of calcium carbonate microspheres and their potential application as drug carriers.

The influence of lecithin from egg yolk (LE) on calcium carbonate (CaCO3) biomineralization was investigated. In the present study, spherical CaCO3 particles were synthesized via coprecipitation in the presence of LE. LE multilamellar liposomes were first tuned by sonication to provide better control over the nucleation of CaCO3. Subsequently, monodisperse microspheres ~2µm in size were generated by controlling the aggregation and growth of CaCO3 under appropriate concentrations of LE. In contrast to unstable vaterite, the microspheres generated in aqueous solution remained stable for at least 10days without transforming into calcite, due to the strong interaction between the LE and calcium ions. The microspheres as drug carriers of doxorubicin (DOX) were assessed and were observed to have a good encapsulation efficiency, sustained drug release without a burst release and notable pH sensitivity. In addition, invivo tumor inhibition examination demonstrated that DOX‑loaded CaCO3 microspheres formulation had more superior efficacy to significantly restrain tumor growth. These novel LE/CaCO3 hybrids may provide novel options for various biomedical applications.

Effect of the tryptone concentration on the calcium carbonate biomineralization mediated by Bacillus cereus

Se evaluaron cinco concentraciones de triptona (0.2%, 0.4%, 0.6%, 0.8% y 1.0%) en procesos de biomineralización de carbonato de calcio, utilizando acetato de calcio al 0.5%. Todos los ensayos se hicieron con una cepa de Bacillus cereus, aislada de los jardines de la Universidad Pontificia Bolivariana (Medellín, Antioquia, Colombia). Los experimentos fueron monitoreados con mediciones de pH y análisis mineralógicos de difracción de rayos X (XRD), espectroscopía de infrarrojo con transformada de Fourier (FTIR) y microscopía electrónica de barrido (SEM). La vaterita fue el polimorfo predominante en los precipitados después de 6 días de proceso. Sin embargo, una proporción considerable de calcita (por encima de 30%) apareció cuando la concentración de triptona fue de 0.4% y menor. Adicionalmente, los experimentos tuvieron una formación de precipitados similar (entre 3.2 y 3.6 g/L), menos el ensayo con 0.2% de triptona, que presentó una baja producción de carbonato de calcio (1.79 g/L), indicando que una concentración de triptona menor a 0.4% limitaría el metabolismo bacteriano y la formación de CO2, necesaria para la producción de carbonato de calcio.

Amyloid Assembly Endows Gad m 1 with Biomineralization Properties.

Acid proteins capable of nucleating Ca2+ and displaying aggregation capacity play key roles in the formation of calcium carbonate biominerals. The helix-loop helix EF-hands are the most common Ca2+-binding motifs in proteins. Calcium is bound by the loop region. These motifs are found in many proteins that are regulated by calcium. Gad m 1, an Atlantic cod β-parvalbumin isoform, is a monomeric EF-hand protein that acts as a Ca2+ buffer in fish muscle; the neutral and acid apo-forms of this protein can form amyloids. Since Ca2+-nucleating proteins have a propensity to form extended β-strand structures, we wondered whether amyloid assemblies of an EF-hand protein were able to influence calcium carbonate crystallization in vitro. Here, we used the Gad m 1 chain as a model to generate monomeric and amyloid assemblies and to analyze their effect on calcite formation in vitro. We found that only amyloid assemblies alter calcite morphology.

Mechanical properties and durability of bio-blocks with recycled concrete aggregates

Harnessing bio-processes to improve the mechanical properties of building materials have gained interest in developing green construction. One of the bio-processes utilized to improve the mechanical properties of building materials is the bio-mineralization of calcium carbonate by the activity of the urease-positive bacterium. In this research, the recycled concrete aggregates, as one of the main constituents of construction and demolition wastes, were used to produce bio-blocks by the bio-mineralization of CaCO3 and the results were compared to bio-blocks produced with natural aggregates. Furthermore, the durability and mechanical properties of both types of bio-blocks were investigated. The difference in compressive strengths of bio-blocks made with both aggregates was less than 10%. The results showed that bio-mineralization reduced the water absorption of the RCA bio-blocks, which is one of the drawbacks of recycled concrete aggregates. In addition, durability tests revealed that the bio-blocks maintained their strength under freeze thaw cycles and high temperatures.

ATP-Decorated Mesoporous Silica for Biomineralization of Calcium Carbonate and P2 Purinergic Receptor-Mediated Antitumor Activity against Aggressive Lymphoma.

Adenosine triphosphate (ATP) is an important transmitter that mediates various biological effects via purinergic receptors (P2 receptors) in cancer. We investigated the antitumor activity of ATP-decorated and doxorubicin (DOX)-loaded mesoporous silica with biomineralization of calcium carbonate against a highly aggressive and metastatic murine lymphoma called Dalton's lymphoma (DL). Our results suggest that this nanocomposite has unique effects with respect to the morphology and properties of calcium carbonate on the surface of the nanoparticle. DOX in the nanoparticles was prevented from quick release via the interactions of the phosphate group present on ATP and calcium carbonate. This construct is significantly tumoricidal against parental and DOX-resistant DL cells and is thus a promising candidate for applications in drug delivery. The composite nanomaterial has excellent biocompatibility with higher uptake and acts via the participation of the purinergic receptor P2X7. The nanocomposite induces significantly higher apoptosis in tumor cells compared with DOX alone. Treatment of DL-bearing mice with the construct significantly reduces tumor burden, in addition to augmenting the lifespan of tumor-bearing mice as demonstrated by a sustained healthy life of the animals and improved histopathological parameters.