A team of undergraduates from Imperial College London competed against 220 teams from universities around the world at the 2014 International Genetically Engineered Machine (iGEM) competition, which was held in Boston, USA.
They were given a kit of biological parts including harmless bacteria and cells. Working at the College over the summer, the Imperial team undertook a project and used the parts to design and build a new type of membrane.
The team created a membrane using bacterial cellulose, a by-product of the Gluconacetobacter xylinus bacteria found in fermented kombucha herbal tea. They sequenced the entire genome of the bacteria, re-coded its DNA, and inserted it into harmless E. coli, where bacterial cellulose production could be optimised.
As the membrane is made from a naturally occurring substance, it is more environmentally friendly than standard membranes, which are generally made from non-biodegradable materials such as plastic. It is also 20 times stronger than conventional membranes, which means that it can withstand high water pressures, making it more efficient at straining out toxins from water.
The team estimates that it would be six times less costly to make than conventional membrane technology, which means it could cut costs in industry. It could also be customised during the manufacturing process to filter out a specific toxin or harmful trace metal, making it potentially more adaptable than current technologies.
The team has already carried out tests to determine how effective the membrane is at filtering the harmful trace metal nickel, an industry by-product that can cause water contamination. Their membrane technology was able to remove more than 99.9 per cent of nickel from a concentrated nickel solution of 30,000 parts per million.