Scientists at the Montana Tech University have developed a water filtration material based on a symbiotic culture of bacteria and yeast. It has long been used in cooking for the fermentation of drinks, resulting in, for example, the well-known kombucha. American scientists experimented with bacterial species and settled on Acetobacter, which is adapted to live in an acetic environment.
Actually, Acetobacter itself produces acetic acid to fight other bacteria, including those that create a special kind of pollution – biofilm. This slimy substance of bacterial colonies first covers the surface of the filters, and then completely disables them, much earlier than the planned service life. But everything changes if bacteria are deprived of the ability to survive on the surface of the filter due to acetic acid.
The final composition of the “live filter” includes black tea, sugar, distilled white vinegar and water, plus yeast and Acetobacter bacteria. With this solution, the scientists impregnated thin sheets of cellulose and put them together in the form of a multi-row membrane. Experiments have shown that the degree of water purification in it is not higher than the existing polymer analogues, but a biofilm is almost not formed on it, and the filter lasts many times longer. And the combination of bacteria and yeast has the ability to regenerate, grow and fill the gaps in its own defenses.
An additional plus is that all components of such a filter are cheap and completely decompose in natural environment.