Extreme biomineralization: the case of the hypermineralized ear bone of gray whale (Eschrichtius robustus)

Abstract

Selected hypermineralized bones (rostrum and tympanic bullae) have yet to be characterized for diverse species of whales (Cetacea). Hypermineralization in these structures is an example of extreme biomineralization that, however, occurs at temperatures around 36 °C. In this study we present the results of analytical investigations of the specimen of tympanic bulla isolated from gray whale (Eschrichtius robustus) for the first time. Examination of the internal surface of the bone mechanically crushed under a press revealed the presence of a lipid-containing phase, which did not disappear even after complete demineralization of the bone material. Additionally, analytical investigations including CARS, ATR-FTIR, Raman and XRD confirmed the presence of carbonated bioapatite and a collagen- lipid complex as the main components of this up to 2.34 kg/cm3 dense bone. Our experimental results open the way for further research on understanding of the principles of hypermineralization in highly specialized whale bones.

Ion Pathways in Biomineralization: Perspectives on Uptake, Transport, and Deposition of Calcium, Carbonate, and Phosphate

“… 62 Furthermore, there are pathways that are specific to one process, such as bone elongation in the growth plate, or pathways that are responsible for producing hyper-mineralized bones. 63 It is therefore challenging to identify common underlying ion pathways in bone formation.…”

“…The complexity may also be a strategy that is tailored to meet different requirements, such as rapid surface thickening of bone, especially during early development, versus maintenance of mature bone by remodeling . Furthermore, there are pathways that are specific to one process, such as bone elongation in the growth plate, or pathways that are responsible for producing hyper-mineralized bones . It is therefore challenging to identify common underlying ion pathways in bone formation.…”

Calcium carbonate: controlled synthesis, surface functionalization, and nanostructured materials

“…9 CaCO 3 is also synthesized by bacteria, 10 even in extreme biomineralization conditions, 11 and is an essential component of mineralized tissues as in the apatitic whale bone. 12,13 Crystalline CaCO 3 exhibits three polymorphs: hexagonal vaterite, orthorhombic aragonite, and rhombohedral calcite, in order of increasing thermodynamic stability. 14 Two hydrated crystal phases of CaCO 3 , monohydrocalcite (CaCO 3 ÁH 2 O) and ikaite (CaCO 3 Á6H 2 O), have been known for more than a century, while recently, hemihydrate CaCO 3 Á 1 2 H 2 O with a monoclinic structure has been discovered.…”

Forced Biomineralization: A Review

“…Our review of numerous recent scientific publications on biomineralization has revealed emphasis of the overall scientific attention towards calcification [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ], biosilicification [ 14 , 15 , 16 ], biomagnetism [ 17 , 18 ], and multiphase biomineralization [ 19 , 20 , 21 , 22 , 23 ]. Traditional objects of study continue to include molluscs [ 24 , 25 , 26 , 27 , 28 ], sea urchins [ 29 ], and skeletal structures such as eggshells [ 30 ], teeth [ 31 , 32 ], and bones [ 33 , 34 , 35 , 36 ]. While it is understandable to focus on the biomineralizing organisms typically encountered by humans on Earth, this focus tends to overlook a variety of distinct biomineralization pathways seen in extremophiles.…”