Engineers design 'living materials'

MIT engineers have designed coaxed bacterial cells which produces biofilms that can incorporate nonliving materials like gold nanoparticles. The living materials combine the advantages of live cells and respond or produce complex biological molecules, span multiple length scales. These adds functions like conducting electricity or give off light. They want to put both non-living and living organisms to make hybrid materials that can live and function. They worked with bacterium E. coli, which produces biofilms that contains curli fiber that helps it to attach to surfaces. Curli Fiber is made from CsgA. CsgA can be modified by adding peptides, which can capture non-living materials (gold).

The researchers controlled the biofilms' properties and created gold nanowires. The researchers demonstrated how the cells can coordinate with each other to control the composition of the biofilm. Over time, they can change the composition of the material. To add quantum dots to the curli fibers, the researchers engineered cells called SpyTag, which binds to quantum dots. These cells grow with bacterias that produce histidine-tagged fibers. This creates a material that has both quantum dots and gold nanoparticles. This approach may be used to build devices like solar cells, healing materials, diagnostic sensors. The researchers are also interested in coating the biofilms with enzymes that catalyze the breakdown of cellulose, which could be useful for converting agricultural waste to biofuels.

A bacterial cell engineered to produce amyloid nanofibers that incorporate particles like quantum dots or gold nanoparticles.

NOS:

Science is collaborative: MIT engineers worked to together on this approach to design a bacterial cell.

Science is based on evidence: The researchers provided evidence to support their findings. 

Importance of repeatability: This approach will work again and again. It will continue to give the same results. 

Role of curiosity: The engineers are curious to find out more and design more complex devices. 

http://www.sciencedaily.com/releases/2014/03/140323152144.htm