(593e) Identifying the Genetic Mechanisms of Diatom Silicification for the Production of Novel Biomaterials

Biological systems present attractive alternatives for traditional industrial processes in the search for new and more environmentally friendly technologies. The production of silica-based materials is one such area for which biological processes exist that may be able to supplement, replace, or improve current manufacturing approaches. Specifically, the unicellular, eukaryotic algae know as diatoms are recognized for their ability to synthesize cell walls made almost entirely of hydrated silica at ambient temperatures and pressures. Additionally, these cell wall structures typically contain a high degree of intricate micro- and nano-scale patterning. As such, there is increasing interest in the biosynthetic potential of diatoms for producing advanced silica-based materials, with applications ranging from catalyst support to drug delivery to micro-optics.

However, the engineering of diatom-derived materials is in its infancy, in part due to an incomplete understanding of the mechanisms underpinning siliceous cell wall synthesis. To help address this lack of knowledge, we are investigating the genetic and molecular mechanisms of diatom silicification, with the ultimate goal of more precisely controlling and engineering this process. ‘Omics approaches applied across both model and non-model diatoms with a variety of silica morphologies are enabling us to identify novel genes influencing the intracellular silica-deposition process that leads to cell wall formation. In one example, we have used a comparative genomics approach incorporating protein structural predictions to identify both new members of previously established silicification-associated protein families as well as potentially novel genes involved in diatom silica formation. Additionally, we are using untargeted proteomics on actively forming silica structures to identify further proteins underlying the mechanisms of silica deposition and pattern formation. Lastly, a small but growing set of genetic tools for use in diatoms will enable us to directly probe candidate silica-associated genes to assess their role in cell wall formation. Through these and other approaches we are working to reveal genetic targets and control mechanisms to engineer diatom silicification for the production of advanced biomaterials.