Biomineralisation

Defining biominerals and organominerals: direct and indirect indicators of life

by Martin Brasier

Evidence for spicule homology in calcareous and siliceous sponges: biminerallic spicules in Lenica sp. (Porifera; ?Protomonaxonida) of early Cambrian age (535-520 Ma) from South China

by Lucy Muir

The relationships of the extant sponge classes, and the nature of the last common ancestor of all sponges, are... more The relationships of the extant sponge classes, and the nature of the last common ancestor of all sponges, are currently unclear. Early sponges preserved in the fossil record differ greatly from extant taxa, and therefore information from the fossil record is critical for testing hypotheses of sponge phylogenetic relationships that are based on modern taxa. New specimens of the enigmatic sponge Lenica sp., from the Early Cambrian Hetang Biota of South China, exhibit an unusual spicule structure. Each spicule consists of a siliceous core with an axial canal, an organic outer layer and a middle layer interpreted to have been originally calcium carbonate. This finding confirms previous work suggesting the existence of biminerallic spicules in early sponges. Combined with data from other early sponges, the new findings imply that the two fundamental spicule structures of modern sponges were derived from a compound, biminerallic precursor. Spicules are therefore homologous structures in Calcarea and Silicea, and if sponges are paraphyletic with respect to Eumetazoa, then spicules may also have been a primitive feature of Metazoa.

Raman spectroscopic study of the mineral composition of cirratulid tubes (Annelida, Polychaeta)

by Olev Vinn

Inconsistencies in proposed annelid affinities of early biomineralized organism Cloudina (Ediacaran): structural and ontogenetic evidences

by Olev Vinn

Carnets de Géologie CG2012_A03

Evolution of a dense outer protective tube layer in serpulids (Polychaeta, Annelida)

by Olev Vinn

Carnets de Géologie CG2011_L05

The role of an internal organic tube lining in the biomineralization of serpulid tubes

by Olev Vinn

Carnets de Géologie CG2011_L01

On the tube ultrastructure and origin of calcification in sabellids (Annelida, Polychaeta)

by Olev Vinn

Ultrastructure and mineral composition of serpulid tubes (Polychaeta, Annelida)

by Olev Vinn

Unique Mg-calcite skeletal ultrastructure in the tube of the serpulid polychaete Ditrupa

by Olev Vinn

Tube structure and ultrastructure of serpulids from the Jurassic of France and Switzerland, its evolutionary implications

by Olev Vinn

The ultrastructure of calcareous cirratulid (Polychaeta, Annelida) tubes

by Olev Vinn

Microscopic evidence of serpulid affinities of the problematic fossil tube ‘Serpula’ etalensis from the Lower Jurassic of Germany

by Olev Vinn

Tube ultrastructure of Pomatoceros americanus (Polychaeta, Serpulidae): implications for the tube formation of serpulids

by Olev Vinn

Moisescu Cristina, Bonneville Steeve, Staniland Sarah, Ardelean Ioan, and Benning Liane G (2011) Iron uptake kinetics and magnetosome formation by Magnetospirillum gryphiswaldense as function of pH, temperature and dissolved iron availability Geomicrobiology Journal 28/7:590-600 doi: 10.1080/01490451.2011.594146

by Liane G. Benning

The dynamics of iron uptake and magnetosome formation by the magnetotactic bacteria (MTB) Magnetospirillum... more The dynamics of iron uptake and magnetosome formation by the magnetotactic bacteria (MTB) Magnetospirillum gryphiswaldense was investigated at a broad range of pH, temperature and iron availability to evaluate the role of MTB in the iron biogeochemical cycle. Except at pH 5.0, all incubations have shown significant bacterial growth. However, magnetosome formation was limited at pH 8.0 and 9.0 as well as at 4°C, 10°C and 35°C. At optimal conditions (i.e., pH 7 and 28°C), the uptake rates of dissolved Fe(III) as a function of initial Fe concentration can be described by a Michaelis-Menten-type kinetic model with a maximum iron uptake rate, Vmax ,, of 11 × 10−12 μmoles cell−1 h−1 and an affinity constant, Ks of 26 μM Fe. High resolution imaging of magnetosomes synthesized at the different pH values, revealed a large range of morphologies and sizes, which illustrate the impact of environmental conditions on the formation of magnetite crystals by MTB.

Acicular nanoparticles formed through coprecipitation of iron salts in the presence of bovine serum albumin

by Martin John Hadley

Published in Journal of Materials Chemistry 2011, coauthored by Adrian J. Wright, Neil A. Rowson and Liam M. Grover.

Coprecipitation of ferric and ferrous iron salts in the presence of Bovine Serum Albumin (BSA) demonstrates an unusual... more Coprecipitation of ferric and ferrous iron salts in the presence of Bovine Serum Albumin (BSA) demonstrates an unusual impact on crystal growth mechanisms and eventual nanoparticle morphology. For BSA 200–800mMol/ml, polycrystalline acicular and haloed spheroid particles were observed and these samples demonstrated surprising magnetic properties, including high coercivity.

Acicular Nanocrystals Formed Through Coprecipitation of Iron Salts in the Presence of Bovine Serum Albumin

by Martin John Hadley

Published in Proceedings of the 2nd International Conference on Nanotechnology: Fundamentals and Applications 2011. Co-authored with Neil A. Rowson, Liam M. Grover.

In this paper we demonstrate a modification of the widely used coprecipitation of ferrous and ferric iron salts to... more In this paper we demonstrate a modification of the widely used coprecipitation of ferrous and ferric iron salts to form magnetic nanoparticles that under ambient conditions induces the formation of acicular nanoparticles with an average aspect ratio of 4:1 and a maximum extension of 700nm. Bovine Serum Albumin (BSA) was mixed with a solution of FeSO4 and FeCl3 (molar ratio 3:2) before NaOH was added dropwise to induce precipitation of iron oxide. Optimising conditions to prevent immediate protein globularisation and persistent network formation indicated BSA massively decelerated precipitation and crystal growth. Time-lapsed electron microscopy indicates the growth of acicular nanocrystals after 48h, highly electron-dense needles were observed after 7 days ageing in situ and aggregation of such structures continued over several weeks. Samples with BSA 495Mol/ml demonstrated high coercivity values which improved over time (from 0.10T after 7 days to 0.38T after 6 weeks) but could not be conclusively attributed to the acicular nanoparticles.

Rodriguez-Blanco, J. D., Shaw, S. and Benning L. G. (2008) How to make ‘stable’ ACC: protocol and structural characterization.Mineralogical Magazine 72/1 p. 283-286 doi: 10.1180/minmag.2008.072.1.283

by Liane G. Benning

The kinetics and mechanisms of nanoparticulate amorphous calcium carbonate (ACC) crystallization to calcite, via... more The kinetics and mechanisms of nanoparticulate amorphous calcium carbonate (ACC) crystallization to calcite, via vaterite, were studied at a range of environmentally relevant temperatures (7.5–25 °C) using synchrotron-based in situ time-resolved Energy Dispersive X-ray Diffraction (ED-XRD) in conjunction with high-resolution electron microscopy, ex situ X-ray diffraction and infrared spectroscopy. The crystallization process occurs in two stages; firstly, the particles of ACC rapidly dehydrate and crystallize to form individual particles of vaterite; secondly, the vaterite transforms to calcite via a dissolution and reprecipitation mechanism with the reaction rate controlled by the surface area of calcite. The second stage of the reaction is approximately 10 times slower than the first. Activation energies of calcite nucleation and crystallization are 73 ± 10 and 66 ± 2 kJ mol−1, respectively. A model to calculate the degree of calcite crystallization from ACC at environmentally relevant temperatures (7.5–40 °C) is also presented.

Biomimetic bone-like composites fabricated through an automated alternate soaking process

by Daniel Strange

Hydroxyapatite-gelatin composites have been proposed as suitable scaffolds for bone and dentin tissue regeneration.... more Hydroxyapatite-gelatin composites have been proposed as suitable scaffolds for bone and dentin tissue regeneration. There is considerable interest in producing these scaffolds using biomimetic methods due to their low energy costs and potential to create composites similar to the tissues they intend to replace. Here, an existing process used to coat a surface with hydroxyapatite under near physiological conditions, the alternate soaking process, is modified and automated using an inexpensive “off-the-shelf” robotics kit. The process is initially used to precipitate calcium-phosphate coatings. Then, in contrast to previous utilizations of the alternate soaking process, gelatin was added directly to the solutions in order to co-precipitate hydroxyapatite-gelatin composites. Samples were investigated with Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy and nanoindentation. Calcium-phosphate coatings formed by the alternate soaking process exhibited different calcium to phosphate ratios with correspondingly distinct structural morphologies. The coatings demonstrated an interconnected structure with measurable mechanical properties, even though they were 95% porous. In contrast, hydroxyapatite-gelatin composite coatings over 2 mm thick could be formed with little visible porosity. The hydroxyapatite-gelatin composites demonstrate composition and mechanical properties similar to those of cortical bone.

Bacterially mediated mineralisation processes lead to biodeterioration of artworks in Maltese catacombs

by Gabrielle Zammit

Gabrielle Zammit, Sergio Sánchez-Moral and Patrizia Albertano (2011) Science of the Total Environment 409, 2773–2782

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Mineral structures formed by bacterial and microalgal biofilms growing on the archaeological surface in Maltese... more Mineral structures formed by bacterial and microalgal biofilms growing on the archaeological surface in Maltese hypogea were studied using Energy Dispersive X-Ray Spectroscopy (EDS) coupled to Environmental Scanning Electron Microscopy (ESEM), X-ray micro-diffraction (XRD) and X-ray fluorescence (XRF). These techniques have shown that mineral structures having different morphologies and chemical composition were associated with the microorganisms in the subaerophytic biofilm. Salt efflorescences and mineral deposits on the archaeological surface were often formed from gypsum (CaSO4.2H2O), halite (NaCl) and calcite (CaCO3). Biogenic carbonates produced by microbial activities were a common occurrence. These assumed different forms, such as the production of mineral coats around cyanobacterial sheaths and the occurrence of calcite fibers with different morphologies on the surface of the biofilms. Moreover, vaterite (CaCO3) spherulites which appeared hollow in cross-section were observed. The presence of struvite was recorded from one catacomb site. These investigations have facilitated the study of the neoformation of metastable minerals by microbially mediated processes, which potentially contribute to a better understanding of the biodeterioration of artworks in Maltese palaeo-Christian catacombs.

Comment on: Fruit and Seed Biomineralization and Its Effect on Preservation

by Lisa-Marie Shillito

Archaeological and Anthropological Sciences
Volume 2, Number 3, 225-229
Shillito, L-M and Almond, MJ

DOI: 10.1007/s12520-010-0041-0 DOI: 10.1007/s12520-010-0041-0