At first glance, they look like scraps of familiar office Eurofoil. And they feel the same to the touch thanks to their slightly bumpy texture. However, it is easy to see that the biofoil samples are made of a different material. Just pour water into the Petri dishes in which they lie and they immediately swell up. “The material has the ability to absorb moisture, which changes its properties. Microcracks form in it, and when it is in the soil, soil microorganisms can reach it much more easily. The decomposition of bio-film itself is based on the action of enzymes produced by these microorganisms,” explained Radim Zelinka from the Space Agri Technologies research group. He is collaborating on research into the practical use of bio-films under the leadership of Vedran Milosavljević.
Scientists produce bio-films from polysaccharide components, i.e., substances similar to starch. This makes them easily biodegradable in soil. “We use furcellaran and chitosan. Furcellaran is a polysaccharide obtained from Furcellaria lumbricalis seaweed. Chitosan is derived from chitin, which is the second most common substance on Earth after cellulose and is obtained from the shells of marine crustaceans,” said Zelinka. Scientists add other components to these substances to give the bio-films strength, flexibility, and thermostability. The production process is simple. “Furcellaran and chitosan are powdery substances. Various stiffeners or elastic substances are added to them, and everything is mixed with water. The resulting mass is then poured onto boards and plates, and the water is allowed to evaporate naturally,” Zelinka described the production process.
Biodegradable films from MENDELU laboratories are mainly used in agriculture. That is why scientists enrich them with phosphorus or potassium during production. These substances serve as nutrients for plants. “We use the films to make baskets that serve as protective material for seedlings. As they decompose, nutrients are gradually released from them. We tested them on lettuce and strawberries in laboratory experiments, and they proved very successful,” said Zelinka. The next phase was a field experiment, which scientists began in May. “We don’t have the full results yet, but based on visual inspection, we know that after 28 days, the material degraded as it should, and the lettuce seedlings thrived,” added the scientist. The next phase of field research will take place in the fall. It will also include testing smaller amounts of bio-foil to reduce its consumption.
The material from which bio-films are made can also take on completely different shapes and thus functions. “We are conducting research on films, but the material is very variable. It can be used to make capsules, balls, or even composite systems with beneficial organisms. Thanks to this, we are also considering its use in simulating conditions outside our planet,” added the scientist, describing the possibilities for further research. In addition to agriculture, bio-films could one day find their place in the packaging industry or pharmaceuticals. The common goal of scientists is to offer an ecological alternative to conventional plastics and thus minimize the burden on the environment.
The project is implemented with financial support from the Technology Agency of the Czech Republic within the TAČR SIGMA program – Support for Early-Career Researchers DC2. This is the first project of its kind supported at Mendel University in Brno.