Coupling metabolism to mineralogical scaffolding for understanding nano-material production in metal-oxidizing bacteria
Abstract
Nanobiotechnology, or the use of microbes to produce compounds or materials applicable to nanotechnology, is an emerging field that"" has the potential to produce novel chemical catalysts, drug delivery systems, biosensors, and new high strength, lightweight materi"als that are of relevance to the Navy. This proposal focuses on a unique group of iron-oxidizing bacteria(FeOB) that catalyze and capture energy from the oxidation of ferrous iron (Fe(II)) as theirprimary energy source and precipitate iron-oxyhydroxide minerals." In the process, these neutrophilic Fe-oxidizing bacteria (FeOB) spin extracellular Fe-oxyhydroxide fibers into a range of ribbon an"d tubular structures that are ~1 micron wide and millimeters to centimeters in length. Each fiber is an aggregate of nanoparticles a"nd exopolymers that has very high, reactive surfaceareas. Only in the past decade have we learned to routinely isolate these obliga""te Fe-oxidizingbacteria from the environment and cultivate them in the laboratory. As a result, much remains to be learned about th"eir biology and potential use in areas like nanobiotechnology. The goal of this proposal is to take advantage of several new isolates of marine FeOB to carry out a systematic research program aimed at better understanding the nature of these biogenic oxides and co"ntrols on their production. There are three primary tasks. One, we will use biochemical and transcriptomic approaches to better unde""rstand how FeOB oxidize Fe, since this process is crucial to the formation and initial organization of the organic-Fe-mineral filame""nts. Two, we will investigate the nature of the organic component of these filaments through a biochemicalcharacterization of the f""ilaments, as well as use comparative genomics to better understand whatgenes may be involved in filament production and transcripto"mics to determine what genes maybe responsible for exopolymer production. The third task will be to gain a better understanding of" the physiological conditions that influence, or control filament production, using a combination of controlled culture conditions a"nd microscopy. Together these approaches willsignificantly advance our understanding of how these bacteria function to produce nanomaterials.This knowledge is essential if we are to realize a long term goal of harnessing this microbial machinery to produce nanow"ires and other metal fiber-reinforced materials, as well as organic-inorganic hybrid frameworks for chemical catalysis, or selective"" filtering systems. Additionally, it maybe possible these could form scaffolds for light weight, but durable fabricswith unique pro"perties.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 07, 2017
- Source ID
- N000141712640
Entities
People
- Clara Chan
Organizations
- Office of Naval Research
- United States Navy
- University of Delaware