Seeing as our planet's fossil resources are limited, researchers are looking for new methods for the production of certain substances, which are not dependent on mineral oil. Photoautotrophic organisms, which gain their energy from light, could be a key to success. The preparation of enzymes allows industrial applications as detergents and for the manufacture of food. The only source materials that organisms such as cyanobacteria require for enzyme synthesis are light, water, nutrient salts and CO2. Complex carbon sources such as sugar are not needed, making the approach a sustainable and renewable alternative to the use of agricultural products for cultivation. The researchers from RUB are attempting to develop such "green cell factories."