Germanium incorporation into the silica of diatom cell walls

Azam, Farooq; Hemmingsen, Barbara B.; Volcani, Benjamin E.

doi:10.1007/bf00409507

Cited by 77 publications

(37 citation statements)

References 16 publications

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“…In the passive incorporation process, it is likely that several different metals would be present in the frustule (Ellwood and Hunter, 2000a). For example, in addition to Mn (detected in this study), Al and Ge have been found in diatom frustules (Azam et al, 1973;Gehlen et al, 2002). Investigation of the atomic structure of the biogenic silica revealed a structural association between Al and Si (Gehlen et al, 2002), which was interpreted as an incorporation of Al during the biosynthesis of the frustule (Gehlen et al, 2002).…”

Section: Nature Of Zn Incorporationmentioning

confidence: 53%

Incorporation of zinc into the frustule of the freshwater diatom Stephanodiscus hantzschii

2009

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Zinc incorporation into the frustule (siliceous cell wall) of the freshwater diatom Stephanodiscus hantzschii was studied for Zn 2+ concentrations ranging from 25 pmol L − 1 to 25 nmol L − 1. A sigmoidal dependency was observed between Zn 2+ concentrations in the culture medium and the concentration of Zn in the frustule.Concentrations of intracellular Zn were positively correlated with Zn in the frustule, suggesting that Zn in the frustule originated from intracellular pools. The processes leading to Zn incorporation into the cell wall were examined by determining the role(s) of Si and Mn via competition experiments. Results demonstrated that Zn competed with Mn for incorporation into the frustule. Zn/Si values for S. hantzschii were consistent with field data obtained from Lake Geneva (Switzerland). The study suggests that the Zn content of fossil frustules could be a valuable tool to study past levels of bioavailable Zn in freshwaters.

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Section: Nature Of Zn Incorporationmentioning

confidence: 53%

Incorporation of zinc into the frustule of the freshwater diatom Stephanodiscus hantzschii

2009

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“…Spicule formation in S. domuncula is inhibited at a germanium/silicon ratio of 0.1 (Simpson et al 1985). Germanium also acts as a competitive inhibitor of silicon transport (Azam et al 1973).…”

Section: Inorganic Factorsmentioning

confidence: 96%

Enzymatic production of biosilica glass using enzymes from sponges: basic aspects and application in nanobiotechnology (material sciences and medicine)

Schröder

Brandt

Schloßmacher

et al. 2007

Naturwissenschaften

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Biomineralization, biosilicification in particular (i.e. the formation of biogenic silica, SiO2), has become an exciting source of inspiration for the development of novel bionic approaches following "nature as model". Siliceous sponges are unique among silica forming organisms in their ability to catalyze silica formation using a specific enzyme termed silicatein. In this study, we review the present state of knowledge on silicatein-mediated "biosilica" formation in marine sponges, the involvement of further molecules in silica metabolism and their potential application in nanobiotechnology and medicine.

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“…Por su parte, el germanio tiene propiedades similares a las del silicio y esta similitud sugiere que el ácido germánico (Ge (OH) 4 ) podría actuar como un inhibidor competitivo de la utilización del silicio en los organismos que lo requieren como nutriente esencial. Los resultados de trabajos experimentales concluyen que el ácido germánico interfiere en el proceso de silicificación de las diatomeas [9,19]. Asimismo, en otros organismos marinos como esponjas silíceas se demostró que la presencia de germanio provoca cambios morfológicos en las espículas durante su deposición intracelular [20,21].…”

Section: Resultados Y Discusiónunclassified

Efecto inhibidor del dióxido de germanio sobre el biofouling del puerto de Mar del Plata

et al. 2018

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RESUMENLa fijación del biofouling sobre cualquier tipo de materiales sumergidos acarrea graves pérdidas económicas como consecuencia del deterioro y la salida de servicio de las distintas estructuras. Este asentamiento de organismos que afecta principalmente a embarcaciones, muelles, boyas, granjas de cultivo y tuberías ocurre de forma secuencial, rápida e inmediata después de la inmersión. En principio se asientan organismos microscó-picos ("microfouling") sobre un film preformado de macromoléculas orgánicas adsorbidas sobre la superficie sumergida; la exudación de polímeros extracelulares de las bacterias forma una especie de malla que sirve de anclaje, sostén y nutrición para las esporas algales y larvas de organismos macroscópicos que arriban más tarde. Esta comunidad denominada biofouling alcanza un espesor considerable en poco tiempo y por esta razón, se busca para su control formulaciones antifouling eficaces cuyos componentes sean ecológicamente aceptables. La inhibición que ejerce el dióxido de germanio sobre el desarrollo de organismos del microfouling (principalmente diatomeas, hongos y bacterias) plantea la posibilidad de su utilización como compuesto antiincrustante. En este sentido se estudió el efecto del dióxido de germanio incluido en una pintura antiincrustante expuesta en el puerto de Mar del Plata durante el período de verano. Los resultados obtenidos indican que la formulación con dióxido de germanio inhibió no solo el asentamiento de diatomeas sino que también afectó la fijación de especies conspicuas del macrofouling (ascidias solitarias y coloniales, gusanos tubícolas y cirripedios). Sobre la base de estos estudios se puede concluir que el dióxido de germanio puede ser empleado como compuesto antifouling dado que demostró alta efectividad sobre un amplio espectro de organismos integrantes de la comunidad.Palabras clave: dióxido de germanio, biofouling, pinturas antifouling amigables con el ambiente. ABSTRACTMarine biofouling on any new material immersed in seawater can lead to extra costs due to increased maintenance, or/and even mechanical wear, and/or biodeterioration that require costly antifouling measures. Fouling organisms growing on immersed manmade surfaces affect hulls, piers, buoys, aquaculture and pipes mainly. Following adsorption of a conditioning film of macromolecules, microorganisms which are the primary colonizers ("microfouling"), are found on unprotected surfaces after only a few minutes of immersion. Extracellular polymeric material exudates from bacteria forms a net that permits anchorage and protection for spores of macroalgae and macroinvertebrate larvae which arrive later. This community is called "biofouling" and develops a thick layer rapidly. As a consequence, the search is orientated to new efficient compounds to formulate environmental friendly antifouling paints.It is well known the inhibitory effect of germanium dioxide on microfouling organisms (diatoms, fungi and bacteria, mainly) and this property promotes its use as antifouling compound. In this sense, g...

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Germanium incorporation into the silica of diatom cell walls

Cited by 77 publications

References 16 publications

Incorporation of zinc into the frustule of the freshwater diatom Stephanodiscus hantzschii

Incorporation of zinc into the frustule of the freshwater diatom Stephanodiscus hantzschii

Enzymatic production of biosilica glass using enzymes from sponges: basic aspects and application in nanobiotechnology (material sciences and medicine)

Efecto inhibidor del dióxido de germanio sobre el biofouling del puerto de Mar del Plata

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