Search results for "Siliceous sponge"
showing 6 items of 16 documents
Sustainable Exploitation and Conservation of the Endemic Lake Baikal Sponge (Lubomirskia baicalensis) for Application in Nanobiotechnology
2009
The large sub-continent of Siberia is one of the richest mineral and oil resources on Earth. In its center, one region has gained prominence: Lake Baikal. It is one of the oldest, the deepest, and the lake with the greatest volume on Earth and is inhabited by more than 1,500 endemic species. It was Pallas (1771) who discovered in the lake a sponge species, Lubomirskia baicalensis (Porifera: Demospongiae), which dominates Lake Baikal's littoral-zone benthos. This sponge species has a distinguished, pronounced body plan which is composed of modules. The application of molecular biological and cell biological techniques has allowed an insight into the richness of the genomic regulatory systems…
The Unique Invention of the Siliceous Sponges: Their Enzymatically Made Bio-Silica Skeleton
2011
Sponges are sessile filter feeders that, among the metazoans, evolved first on Earth. In the two classes of the siliceous sponges (the Demospongiae and the Hexactinellida), the complex filigreed body is stabilized by an inorganic skeleton composed of amorphous silica providing them a distinct body shape and plan. It is proposed that the key innovation that allowed the earliest metazoans to form larger specimens was the enzyme silicatein. This enzyme is crucial for the formation of the siliceous skeleton. The first sponge fossils with body preservation were dated back prior to the “Precambrian-Cambrian” boundary [Vendian (610–545 Ma)/Ediacaran (542–580 Ma)]. A further molecule required for t…
Biogenic Inorganic Polysilicates (Biosilica): Formation and Biomedical Applications
2013
The siliceous sponges, the demosponges and hexactinellid glass sponges, are unique in their ability to form biosilica structures with complex architectures through an enzyme-catalyzed mechanism. The biosilica skeleton of these sponges with its hierarchically structure and exceptional opto-mechanical properties has turned out to be an excellent model for the design of biomimetic nanomaterials with novel property combinations. In addition, biosilica shows morphogenetic activity that offers novel applications in the field of bone tissue engineering and repair. In recent years, much progress has been achieved towards the understanding of the principal enzymes, the silicateins that form the spon…
Enzymatically Synthesized Biosilica
2015
Structural biomaterials are hierarchically organized and biofabricated. Biosilica represents the main mineral component of the sponge skeletal elements, the spicules. We summarize recent data on the different levels of molecular, biological, and structural hierarchies controlling the synthesis of the picturesquely and intricately architectured spicules/skeletons.
A cryptochrome-based photosensory system in the siliceous sponge Suberites domuncula (Demospongiae)
2010
Based on the light-reactive behavior of siliceous sponges, their intriguing quartz glass-based spicular system and the existence of a light-generating luciferase [Muller WEG et al. (2009) Cell Mol Life Sci 66, 537–552], a protein potentially involved in light reception has been identified, cloned and recombinantly expressed from the demosponge Suberites domuncula. Its sequence displays two domains characteristic of cryptochrome, the N-terminal photolyase-related region and the C-terminal FAD-binding domain. The expression level of S. domuncula cryptochrome depends on animal’s exposure to light and is highest in tissue regions rich in siliceous spicules; in the dark, no cryptochrome transcri…
Molecular Biomineralization: Toward an Understanding of the Biogenic Origin of Polymetallic Nodules, Seamount Crusts, and Hydrothermal Vents
2011
Polymetallic nodules and crusts, hydrothermal vents from the Deep Sea are economically interesting, since they contain alloying components, e.g., manganese or cobalt, that are used in the production of special steels; in addition, they contain rare metals applied for plasma screens, for magnets in hard disks, or in hybrid car motors. While hydrothermal vents can regenerate in weeks, polymetallic nodules and seamount crusts grow slowly. Even though the geochemical basis for the growth of the nodules and crusts has been well studied, the contribution of microorganisms to the formation of these minerals remained obscure. Recent HR-SEM (high-resolution scanning electron microscopy) analyses of …