Amyloid fibers, produced by microorganisms, naturally form strong structural networks. These networks are of particular interest because they self-assemble, are stable in harsh environments, and have the potential to be customizable, creating stable proteins and peptides with specific functions. These nanofibers have numerous potential applications, including water purification, tissue engineering scaffolds, drug delivery, and environmental carbon capture.
While most amyloid-based materials utilize natural sources of proteins, it is also possible to genetically engineer E. coli to produce recombinant curli nanofibers (a specific type of amyloid fiber) with desired characteristics. Typically, harvesting genetically engineered amyloid fibers yields low levels of amyloid product. This filtration method provides a simple, fast, and high-yield system for amyloid fiber purification.
This method uses filtration to separate any type of amyloid fiber from other cell contents, as opposed to using traditional affinity tagging. Whole bacterial cultures are passed through filters to isolate the amyloid fibers. Previous technologies require the lysing of cells, filtration does not. Being able to use whole cultures makes this process highly scalable, since bacteria can be grown at many liters at a time. The type of filtration used for this process, ie. vacuum filtration, gravity filtration, or centrifugal filtration, is also highly adaptable. Filters have large pores (1 micron or larger) which optimize fiber recovery.