a1 Scripps Institution of Oceanography, University of California—San Diego,La Jolla, California 92093-0202
a2 Biological & Nanoscale Systems Group, Life Sciences Division, Oak Ridge National Laboratory,Oak Ridge, Tennessee 37831-6123; Department of Biochemistry & Cellular & Molecular Biology, University of Tennessee, Knoxville, TN, 37996-0840; and Molecular Imaging Inc., Agilent Technologies Tempe, Arizona 85282
a3 Biological & Nanoscale Systems Group, Life Sciences Division, Oak Ridge National Laboratory,Oak Ridge, Tennessee 37831-6123
We present a unique approach combining biological manipulation with advanced imaging tools to examine silica cell wall synthesis in the diatom Thalassiosira pseudonana. The innate capabilities of diatoms to form complex 3D silica structures on the nano- to micro-scale exceed current synthetic approaches because they use a fundamentally different formation process. Understanding the molecular details of the process requires identifying structural intermediates and correlating their formation with genes and proteins involved. This will aid in development of approaches to controllably alter structure, facilitating the use of diatoms as a direct source of nanostructured materials. In T. pseudonana, distinct silica morphologies were observed during formation of different cell wall substructures, and three different scales of structural organization were identified. At all levels, structure formation correlated with optimal design properties for the final product. These results provide a benchmark of measurements and new insights into biosilicification processes, potentially also benefiting biomimetic approaches.
(Received April 25 2006)
(Accepted July 27 2006)
(Online publication March 03 2011)
p1 Present address: U.S. Naval Academy, 121 Blake Road, Annapolis, Maryland 21402-5000.