Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (14) Citing Articles via Google Scholar Google Scholar Articles by Ueshima, M. Articles by Tazaki, K. Search for Related Content GeoRef GeoRef Citation

POSSIBLE ROLE OF MICROBIAL POLYSACCHARIDES IN NONTRONITE FORMATION

Department of Earth Sciences, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan

E-mail of corresponding author: tashy{at}d5.dion.ne.jp

Nontronite and microbes were detected in the surface layers of deep-sea sediments from Iheya Basin, Okinawa Trough, Japan. Nontronite, an Fe-rich smectite mineral, was embedded in acidic polysaccharides that were exuded by microbial cells and electron microscopy showed that the nontronite layers were apparently oriented in the polysaccharide materials. We propose that the formation of nontronite was induced by the accumulation of Si and Fe ions from the ambient seawater and that extracellular polymeric substances (EPS) served as a template for layer-silicate synthesis. Experimental evidence for this hypothesis was obtained by mixing a solution of polysaccharides (dextrin and pectin) with ferrosiliceous groundwater. After stirring the mixture in a sealed vessel for two days, and centrifuging, Fe-rich layer silicates were identified within the precipitate of both the dextrin and pectin aggregates, whereas rod-shaped or spheroidal Si-bearing iron hydroxides were found in the external solution. Microbial polysaccharides would appear to have affected layer-silicate formation.

Key Words: Biomineralization • Extracellular Polysaccharides • Microbes • Micromorphology • Microstructure • Nontronite

This article has been cited by other articles:

				K. Tazaki MICROBIAL FORMATION OF A HALLOYSITE-LIKE MINERAL Clays and Clay Minerals, June 1, 2005; 53(3): 224 - 233. [Abstract] [Full Text] [PDF]

				K. Benzerara, T. H. Yoon, N. Menguy, T. Tyliszczak, and G. E. Brown Jr. Nanoscale environments associated with bioweathering of a Mg-Fe-pyroxene PNAS, January 25, 2005; 102(4): 979 - 982. [Abstract] [Full Text] [PDF]

				C. S. Chan, G. De Stasio, S. A. Welch, M. Girasole, B. H. Frazer, M. V. Nesterova, S. Fakra, and J. F. Banfield Microbial Polysaccharides Template Assembly of Nanocrystal Fibers Science, March 12, 2004; 303(5664): 1656 - 1658. [Abstract] [Full Text] [PDF]

				J. C. Fernandez-Caliani, J. C. Fernandez-Caliani, E. Crespo, M. Rodas, J. F. Barrenechea, and F. J. Luque FORMATION OF NONTRONITE FROM OXIDATIVE DISSOLUTION OF PYRITE DISSEMINATED IN PRECAMBRIAN FELSIC METAVOLCANICS OF THE SOUTHERN IBERIAN MASSIF (SPAIN) Clays and Clay Minerals, February 1, 2004; 52(1): 106 - 114. [Abstract] [Full Text] [PDF]

				Silicified Microbes in a Geyser Mound: The Enigma of Low-Temperature Cyanobacteria in a High-Temperature Setting Palaios, April 1, 2003; 18(2): 87 - 109.