E-Mail Today at the Microbiology Society's Annual Conference, Yang Liu, researcher at Hong Kong Polytechnic University, will discuss a new technique to trap and recover microplastics. The method uses bacterial biofilms, a sticky substance created by micro-organisms, to trap microplastic particles. The biofilm is then processed and dispersed, releasing the microplastic particles for processing and recycling. Liu and colleagues used the bacterium Pseudomonas aeruginosa to capture microplastics in a bioreactor. This species of bacteria is found in all environments and has previously been shown to colonise microplastics in the environment. P. aeruginosa biofilms cause the microplastics to aggregate together, eventually causing them to sink. In bioreactors, this makes the microplastics more convenient to collect, according to Liu. Once the microplastics were captured by the biofilms and had sunk to the bottom of the reactor, the researchers used a biofilm-dispersal gene, which caused the biofilm to release the microplastics. Liu explained that this "allows convenient release of microplastics from the biofilm matrix, which is otherwise difficult and expensive to degrade, so that the microplastics can be later recovered for recycling."