Algae are small climate savers. Already extremely efficient in their natural photosynthesis outdoors, they bind ten times more carbon dioxide (CO₂) than land plants. In bioreactors with appropriate sensors, control technology and automation, the efficiency of algae can be increased to hundreds of times that of land plants. Therefore, they hold considerable potential for a climate-neutral circular economy. With the PhotoBionicCell research project, we are demonstrating a possible approach for the industrial biologization of tomorrow.
The bioreactor can be used to automatically cultivate algae and control their growth. For this purpose, the algae liquid is pumped upwards into the surface collectors, where it is distributed in a uniform flow and then flows back into the cultivator. During this circulation, the algae cells convert sunlight, carbon dioxide and water into oxygen and chemical energy carriers or organic valuable substances by means of photosynthesis in their chloroplasts. In this way, the biomass is cultivated in a closed cycle that is highly efficient and saves resources.
In order to create the best possible conditions for the microorganisms, the interaction of proven control technology with the latest automation components comes into play. A holistic gassing concept ensures that the carbon dioxide extracted from the air is evenly distributed in the circulating biofluid.
A major challenge with bioreactors is to accurately determine the amount of biomass. For this purpose, our developers rely on a quantum technology sensor from the start-up Q.ANT. This provides precise and real-time information about the growth of the organisms. The algae are fed to it automatically and continuously by Festo microfluidics. The quantum sensor isable to optically detect individual cells so that the amount of biomasscan be determined exactly. In addition, it examines the cells for their vitality. Only then is it possible to react to process events in advance and to regulate them.
Depending on the nutrients supplied to the algal biomass, fatty acids, color pigments and surfactants are formed as products of their metabolic processes. They serve as starting materials for the production of medicines, foodstuffs, plastics, cosmetics or fuels. Unlike petroleum-based products, biologically based end products can usually be biodegraded and - in keeping with an overall circular economy - recycled in a climate-neutral process.
For the work on PhotoBionicCell, our researchers focused on the cultivation of the blue-green algae Synechocystis. It produces color pigments, omega-3 fatty acids and polyhydroxybutyric acid (PHB). The resulting PHB can be processed into a filament for 3D printing by adding other substances. With this modern production technology, complex shapes of sustainable plastic components or packaging can be produced in a short time. In the PhotoBionicCell, for example, specific fastening clips made of the bioplastic are installed.