In 2050, the global demand for nutritious protein will increase with approximately 50%. However, the traditional fertilizer-feed-food chain already exceeds the ecological carrying capacity of earth. Therefore, researchers are searching for new and sustainable sources of high protein feed and food to solve this pressing problem. The production of Single Cell Protein (SCP) or microbial protein integrates seamlessly into this societal needs. Microbial technology would be the most resource-efficient way to produce nutritious protein.

Purple bacteria (PB) are one of the most attractive types of single cell protein as they can grow in all combinations of photo-, chemo-, auto-, and heterotrophic conditions. Moreover, their nutritional properties are outstanding, producing by-products such as protein, carotenoids, phytohormones and vitamins. In addition, the autotrophic cultivation of purple bacteria on a biotechnological level is completely unknown. Our hypothesis is that each type of metabolism can give expression to different nutritional properties such as the profile in essential amino acids, the gastro-intestinal digestibility and the content of nucleic acids. Therefore, different process parameters could results in a tuned end product (microbial protein), which can be perfectly matched to the needs of certain organisms (human, chicken, pig, …).