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Dai J.-G.,Plateau State University | Wang C.-S.,Plateau State University | Hebert R.,Laval University | Santosh M.,Kochi University | And 2 more authors.
Chemical Geology | Year: 2011

The Zhongba ophiolite is located in the western part of the Yarlung Zangbo Suture Zone (YZSZ) separating Eurasia to the north from the Indian plate to the south. This ophiolite comprises a well-preserved mantle sequence dominated by harzburgites with minor dunites. Highly depleted modal, mineral and bulk rock compositions of the harzburgites indicate that they are residues after moderate to high degrees of partial melting (13-24%) mainly in the spinel-stability field. These rocks display typical U-shaped chondrite-normalized Rare Earth Element (REE) patterns and fractionated chondrite-normalized Platinum Group Element (PGE) patterns. These characteristics, in combination with their hybrid mineral and whole-rock compositions intermediate between those of abyssal and forearc peridotites, indicate melt-rock interaction resulting in the selective enrichment of LREE and Pd. We propose a two-stage model to explain the generation of the Zhongba harzburgites: 1) original generation from a MORB-source upper mantle, and 2) subsequent trapping as part of a mantle wedge above a subduction zone. Comparable observations from the ophiolitic massifs along the whole YZSZ allow us to propose that a ca. 2500-km long complex subduction system was active between India and the Lhasa terrane, Burma, and the Karakoram microcontinent within the Neo-Tethys during the Early Cretaceous, similar to the modern active intra-oceanic subduction systems in the Western Pacific. © 2011 Elsevier B.V.

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: KBBE.2010.3.2-01 | Award Amount: 3.87M | Year: 2010

The SPECIAL project aims at delivering breakthrough technologies for the biotechnological production of cellular metabolites and extracellular biomaterials from marine sponges. These include a platform technology to produce secondary metabolites from a wide range of sponge species, a novel in vitro method for the production of biosilica and recombinant technology for the production of marine collagen. Research on cellular metabolites will be based upon our recent finding that non-growing sponges continuously release large amounts of cellular material. Production of biosilica will be realized through biosintering, a novel enzymatic process that was recently discovered in siliceous sponges. Research on sponge collagen will focus on finding the optimal conditions for expression of the related genes. Alongside this research, the project will identify and develop new products from sponges, thus fully realizing the promises of marine biotechnology. Specifically, the project will focus on potential anticancer drugs and novel biomedical/industrial applications of biosilica and collagen, hereby taking advantage of the unique physico-chemical properties of these extracellular sponge products. The consortium unites seven world-class research institutions covering a wide range of marine biotechnology-related disciplines and four knowledge-intensive SMEs that are active in the field of sponge culture, drug development and nanobiotechnology. The project is clearly reflecting the strategic objectives outlined in the position paper European Marine Strategy (2008); it will enhance marine biotechnology at a multi-disciplinary, European level and provide new opportunities for the European industry to exploit natural marine resources in a sustainable way. In particular the biotechnological potential of marine sponges, which has for a long time been considered as an eternal promise, will be realized through the SPECIAL project.

Agency: Cordis | Branch: FP7 | Program: CP-TP | Phase: KBBE.2012.3.2-01 | Award Amount: 8.15M | Year: 2012

Marine organisms, in particular sponges and their associated microorganisms, are an inexhaustible source of novel bioactive (lead) compounds for biomedical application. Industrial exploitation of this natural resource using traditional approaches is, however, hampered, with a few exceptions, by unsolvable supply problems - despite of numerous efforts in the past. Therefore, there is, very likely, only one way: to start from the genes encoding the bioproducts, or their biosynthetic pathways, to sustainably obtain the active molecules in sufficient amounts. The aim of the presented industry-driven integrating project is to combine the knowledge in marine genomics, chemogenetics and advanced chemistry to produce recombinantly prepared novel secondary metabolite (lead) compounds and analogous from them, as well as pharmacologically active peptides, and to bring them up to the pre-clinical, and hopefully also to the clinical studies. This ambitious approach is based on breakthrough discoveries and the results of previous successful EU projects of members of the applying consortium, including European leaders (or worldwide leaders) in marine (sponge) genomics, metagenomics (polyketide synthase clusters), combinatorial biosynthesis and marine natural product chemistry/structure elucidation. This multidisciplinary project, driven by high-tech genomics-based SMEs with dedicated interest in bringing marine-biotechnology-derived products to the market, will also involve the discovery and sustainable production of bioactive molecules from hitherto unexploited extreme environments, such as hydrothermal vents and deep-sea sources, and the expression/scale-up of unique enzymes/proteins of biomedical and biotechnological interest. The molecular-biology-based strategies developed in this project for a sustainable exploitation of aquatic molecular biodiversity will further strengthen the international position and effectiveness of European (SME-based) blue biotechnology industry.

Arandiyan H.,Tsinghua University | Dai H.,Beijing University of Chemical Technology | Deng J.,Beijing University of Chemical Technology | Wang Y.,Beijing University of Chemical Technology | And 3 more authors.
Chemical Communications | Year: 2013

Highly dispersed Ag nanoparticles supported on high-surface-area 3DOM La0.6Sr0.4MnO3 were successfully generated via the dimethoxytetraethylene glycol-assisted gas bubbling reduction route. The macroporous materials showed super catalytic performance for methane combustion. © 2013 The Royal Society of Chemistry.

Jochum K.P.,Max Planck Institute for Chemistry | Wang X.,National Research Center for Geoanalysis | Vennemann T.W.,University of Lausanne | Sinha B.,Max Planck Institute for Chemistry | Muller W.E.G.,Universitatsmedizin Mainz
Chemical Geology | Year: 2012

The deep-sea sponge Monorhaphis chuni forms giant basal spicules, which can reach lengths of 3. m; they represent the largest biogenic silica structures on Earth that is formed from an individual metazoan. The spicules offer a unique opportunity to record environmental change of past oceanic and climatic conditions. A giant spicule collected in the East China Sea in a depth of 1110. m was investigated. The oxygen isotopic composition and Mg/Ca ratios determined along center-to-surface segments are used as geochemical proxies for the assessment of seawater paleotemperatures. Calculations are based on the assumption that the calculated temperature near the surface of the spicule is identical with the average ambient temperature of 4. °C. A seawater temperature of 1.9. °C is inferred for the beginning of the lifespan of the Monorhaphis specimen. The temperature increases smoothly to 2.3. °C, to be followed by sharply increased and variable temperatures up to 6-10. °C. In the outer part of the spicule, the inferred seawater temperature is about 4. °C. The lifespan of the spicule can be estimated to 11,000 ± 3000. years using the long-term trend of the inferred temperatures fitted to the seawater temperature-age relationships since the Last Glacial Maximum. Specimens of Monorhaphis therefore represents one the oldest living animals on Earth. The remarkable temperature spikes of the ambient seawater occurring 9500-3100. years. B.P. are explained by discharges of hydrothermal fluids in the neighborhood of the spicule. The irregular lamellar organization of the spicule and the elevated Mn concentrations during the high-temperature growth are consistent with a hydrothermal fluid input. © 2012 Elsevier B.V..

Schlossmacher U.,Johannes Gutenberg University Mainz | Wiens M.,Johannes Gutenberg University Mainz | Schroder H.C.,Johannes Gutenberg University Mainz | Wang X.,National Research Center for Geoanalysis | And 2 more authors.
FEBS Journal | Year: 2011

Silicateins are unique enzymes of sponges (phylum Porifera) that template and catalyze the polymerization of nanoscale silicate to siliceous skeletal elements. These multifunctional spicules are often elaborately shaped, with complex symmetries. They carry an axial proteinaceous filament, consisting of silicatein and the scaffold protein silintaphin-1, which guides silica deposition and subsequent spicular morphogenesis. In vivo, the synthesis of the axial filament very likely proceeds in three steps: (a) assembly of silicatein monomers to form one pentamer; (b) assembly of pentamers to form fractal-like structures; and finally (c) assembly of fractal-like structures to form filaments. The present study was aimed at exploring the effect of self-assembled complexes of silicatein and silintaphin-1 on biosilica synthesis in vitro. Hence, in a comparative approach, recombinant silicatein and recombinant silintaphin-1 were used at different stoichiometric ratios to form axial filaments and to synthesize biosilica. Whereas recombinant silicatein-α reaggregates to randomly organized structures, coincubation of silicatein-α and silintaphin-1 (molecular ratio 4: 1) resulted in synthetic filaments via fractal-like patterned self-assemblies, as observed by electron microscopy. Concurrently, owing to the concerted action of both proteins, the enzymatic activity of silicatein-α strongly increased by 5.3-fold (with the substrate tetraethyl orthosilicate), leading to significantly enhanced synthesis of biosilica. These results indicate that silicatein-α-mediated biosilicification depends on the concomitant presence of silicatein-α and silintaphin-1. Accordingly, silintaphin-1 might not only enhance the enzymatic activity of silicatein-α, but also accelerate the nonenzymatic polycondensation of the silica product before releasing the fully synthesized biosiliceous polymer. © 2011 The Authors Journal compilation © 2011 FEBS.

Wang X.,Johannes Gutenberg University Mainz | Wang X.,National Research Center for Geoanalysis | Schlossmacher U.,Johannes Gutenberg University Mainz | Schroder H.C.,Johannes Gutenberg University Mainz | Muller W.E.G.,Johannes Gutenberg University Mainz
Soft Matter | Year: 2013

Siliceous sponges form their skeletal elements, the spicules, enzymatically via the sponge-specific enzyme silicatein. The enzymatic product of silicatein in vitro is a bio-silica polymer that is not processed/hardened by phase separation. In the present study we applied a two-phase system to investigate the transition of bio-silica, formed by silicatein, from the lucid state to the opaque/turbid state. We report for the first time that the polyether polyethylene glycol [PEG] causes a rapid transition of the lucid bio-silica to the opaque/turbid state. For the experiments the recombinant silicatein from the demosponge Suberites domuncula had been used. This process is rapid (1 h) and proceeds at ambient temperatures and low (<1 mM) ortho-silicate concentrations. The condensed material can be easily eye-inspected; it has been characterized by microscopy as a smooth and solid gel. The presence of PEG displays an accelerating effect on the enzymatic polycondensation reaction. In a second part of this study a natural, sponge protein has been isolated. The 22-24 kDa protein, termed the spicule-binding protein, causes a likewise increased sol-gel transition of bio-silica. The gene corresponding to this protein was identified in S. domuncula and found to encode for a protein containing the nidogen domain. The recombinant protein, the nidogen-related protein, was prepared and likewise found to induce gelation of bio-silica due to phase separation. It is proposed that the PEG-induced phase separation process follows a mechanism during which PEG together with silicatein neutralizes the negative surface charges of the formed bio-silica nanoparticles. Further on it is adopted that the phase separation process, caused by the nidogen-like protein (spicule-binding protein), can be ascribed best to a polymerization-induced phase separation process. It is concluded that the induction of the gelation process of bio-silica described here can be used during biomimetic fabrication of new bio-silica structures. This journal is © 2013 The Royal Society of Chemistry.

To obtain reliable in situ information on the distribution and speciation of Pb in plants with low Pb content, special attention needs to be paid to the synchrotron radiation based micro-X-ray fluorescence and micro-X-ray absorption near edge structure (μ-XANES) spectrometry to avoid specious results in the chosen XRF region of interest and speciation linear combination fitting. First, an Arabidopsis thaliana shoot cultured in a Pb solution is analyzed to obtain two-dimensional Pb distribution graphs, where an overlap of Pb, As, Se, and Br lines in synchrotron radiation based micro-X-ray fluorescence spectra is found. To avoid this overlap, (1)As K-L3 and Pb L3-M5, (2)As K-M3, (3)Pb L2-M4, (4)Se K-L3, and (5)Br K-M3 lines should be chosen in the region of interest. The Pb content in the seed coat, root, and stem are 48.2, 17.3, and 5.8 times higher, respectively, than in the leaf, while the Pb content in the seed coat, root, stem, and leaf increased 3458, 1241, 420, and 72 times, respectively, compared with the A. thaliana sample without a Pb solution soak. Second, Pb speciation of the same shoot is analyzed using μ-XANES. It is important to define a combination fitting range because different possible Pb combinations can emerge using different ranges. Different speciations were found in the root[Pb(Ac)2 and PbSO4], stem[Pb(Ac)2 and Pb3(PO4)2], leaf[Pb(OH)2 and Pb5Cl(PO4)3], and seed coat[Pb3(PO4)2, Pb(OH)2, and PbCO3] between the fitting range of E0-20eV and E0+70eV. A more complete Pb XANES database with more references, especially organic Pb compounds, is needed. © 2013 John Wiley & Sons, Ltd.

Shen Y.-T.,National Research Center for Geoanalysis
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2014

In order to investigate plant reacting mechanism with heavy metal stress in organ and tissue level, synchrotron radiation micro X-ray fluorescence(μ-SRXRF) was used to determine element distribution characteristics of K, Ca, Mn, Fe, Cu, Zn, Pb in an Arabidopsis thaliana seedling grown in tailing dam soil taken from a lead-zinc mine exploration area. The results showed a regular distribution characters of K, Ca, Fe, Cu and Zn, while Pb appeared not only in root, but also in a leaf bud which was beyond previously understanding that Pb mainly appeared in plant root. Pb competed with Mn in the distribution of the whole seedling. Pb may cause the increase of oxidative stress in root and leaf bud, and restrict Mn absorption and utilization which explained the phenomenon of seedling death in this tailing damp soil. Speciation of Pb in Arabidopsis thaliana and tailing damp rhizosphere soil were also presented after using PbL3 micro X-ray absorption near edge structure(μ-XANES). By comparison of PbL3 XANES peak shape and peak position between standard samples and rhizosphere soil sample, it was demonstrated that the tailing damp soil was mainly formed by amorphous forms like PbO(64.2%), Pb(OH)2(28.8%) and Pb3O4(6.3%) rather than mineral or organic Pb speciations. The low plant bioavailability of Pb demonstrated a further research focusing on Pb absorption and speciation conversion is needed, especially the role of dissolve organic matter in soil which may enhance Pb bioavailability.

Shen Y.-T.,National Research Center for Geoanalysis
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2012

It is difficult to get accurate, precise and reliable analytical data when using X-ray fluorescence spectrometry (XRF) to determinate sulfur in geological sample. The possible ways to improve sulfur determination accuracy are discussed. Sulfur, and the major, minor and trace elements in soils were determined by polarization energy dispersion XRF (EDXRF) spectrometry and the element profiles and vertical distribution were obtained. Based on this, replacement of two short-term vegetation soil profiles was studied. Significant correlations among the vertical distribution of soil organic carbon content (TOC), organic carbon stable carbon isotopes (δ 13C) and several elements were found. The study showed that the EDXRF method can be well applied to element soil geochemical cycle and carbon cycle researches.

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