Hi-tech tea

Cellulose, which is harvested from trees and plants, is a very common material used to make paper and cardboard. But some harmless bacteria found in a kind of fermented tea, also produce a very strong and pure form of cellulose. When tea aficionados ferment their kombucha tea (a form of green tea) a clump of cellulose floats to the surface.

Bacterial cellulose like this is already used to make ingredients in cosmetic and materials for headphones, but it could soon be used in a wide variety of medical applications.

Our team at Imperial College London, lead by undergraduates, have found a way to modify the DNA of these bacteria so that they produce cellulose on command. The results were published yesterday (Monday 30th May) in the journal, Proceedings of the National Academy of Scientists. This technique also allows our scientists to ‘weave’ proteins and other biomolecules into the fabric of the bacterial cellulose as it grows.

One application is to use the bacterial cellulose as a scaffold to build tissue for transplant. Human cells can grow on the cellulose because it is biocompatible and biodegradable. We are looking at ways to develop fabric for bandages and dressing with built in sensors for infection. The team has worked out ways to make the cellulose to produce proteins that detect chemicals like biological toxins and infection. The material will change colour in response as a warning.

The problem that many medics face in crisis situations where clean water has to be trucked in could also be alleviated by this material. One potential application that members of the team are already pursuing commercially could see improved water filters being developed. These could be patterned with proteins that bind tightly to contaminants and remove them from water supplies.

The real big achievement here has been that this was a project from a team of undergraduates that has now become a major research paper.