Bacterial Bioplastic
Researchers from the Institute of Biotechnology at the Swiss Federal Institute of Technology in Zurich (ETH) cultured bacteria with the ability to synthesize biopolymers. The material is environmentally friendly and fully biodegradable. "Pseudomonas oleovorans" is the name of the tiny elves that are currently making ETH biologists happy. The bacteria impress with their unbridled appetite. They process the fatty acids that the researchers offer them at breathtaking speed.
The material that accumulates when the microbes are "fattened" is interesting. It is a biopolymer, a plastic. "Our bacteria synthesize polyesters with a high molecular weight," explains Birgit Kessler from the Institute of Biotechnology. To encourage the process, the scientists provide their subjects with excess fatty acids and deprive them of other food sources. The bacteria produce monomers from these fatty acids, which are linked to polymers and stored in this way - the bio-plastic is ready. Its special advantage: As a storage material for living cells, it is completely biodegradable.
Birgit Kessler reports: "In order to obtain the polymer, we have to dissolve the bacteria". To do this, the researchers extract the plastic from the bacterial cells with solvents or dissolve the microbes with chemicals. The polymer can then simply be filtered off. The plastic can be used in a wide variety of ways: "You can use it to coat paper, for example, to make it water-repellent," says Kessler. She sees another application in medicine, where elastic properties are required. However, because of the small quantities, the bacterial plastic is currently ten times more expensive than chemically produced products.
