Bacterial cellulose is synthesized by bacteria through a transformative process where sugar is metabolized into cellulose. The necessary sugar can be obtained from food production waste,
for example. The process takes place at the liquid-air interface, as
these bacteria are strictly aerobic. This biochemical process gives
rise to expansive biofilm formations on liquid surfaces, which can
subsequently be converted into a durable and environmentally
friendly alternative to leather. Moreover, bacterial cellulose has a
higher purity and stability compared to its plant-based counterpart,
which makes it extremely biocompatible.
Throughout the project, numerous methods for producing bacterial cellulose have been explored. Techniques ranged from using Kombucha and Mycoderma aceti to simply employing a pure culture of bacteria. A variety of production techniques were explored, encompassing static cultivation, dynamic cultivation, and cultivation of bacteria on oxygen-exchange membranes. Moreover, experiments have been conducted to assess the capability of growth on diverse media, such as fruit-based mediums or dyeing the bacterial cellulose during growth to produce different colors.
The challenge in the final experiment is to cultivate a three-dimensional biofilm. This method has the benefit of being able to cover additively produced parts, facilitating the direct creation of three-dimensional products, without the necessity for sewing or extensive manual post-processing. A shoe was chosen as a demonstrative object for this procedure, considering shoes typically necessitate hours of manual labor, thus making them an optimal testing subject. To achieve this, a specialized machine setup has been developed, which moistens the surface of the shoe mold every 20 minutes for several days. This procedure allows the bacteria to settle there and grow their biofilm on a three-dimensional surface, thanks to the regular supply of nutrients.