Thursday, 16 October 2014

Using biofilms for society’s advantage

Biofilms are communities of bacteria ensconced in a slimy, but extremely tough, matrix of extracellular material composed of sugars, proteins, genetic material and more. During biofilm formation individual bacteria pump out proteins that self-assemble outside the cell -- creating tangled networks of fibers that essentially glue the cells together into communities that keep the bacteria safer than they would be on their own.

Normally considered a bad thing, biofilms also self-assemble and self-heal. In looking at this, researchers have genetically fused a protein with a particular desired function -- for example, one known to adhere to steel -- onto a small protein called CsgA that is already produced by E. coli bacteria. The appended domain then went along for the ride through the natural process by which CsgA gets secreted outside the cell, where it self-assembled into supertough proteins called amyloid nanofibers. These amyloid proteins retained the functionality of the added protein -- ensuring in this case that the biofilm adhered to steel.

This could be useful in materials science. It could be possible to produce a raw material as a building block, they orchestrate the assembly of those blocks into higher order structures and maintain that structure over time.

For further details see: Wyss Institute for Biologically Inspired Engineering atHarvard.

Posted by Tim Sandle