This document discusses single cell proteins (SCP), which are dried cells of microorganisms that can be used as a dietary protein supplement. SCPs are produced using biomass as a raw material and various microorganisms like fungi, algae, and bacteria that are cultured on the biomass. The production involves selecting suitable microorganism strains, fermenting them, harvesting the cells, and processing them for use as a protein supplement in foods. SCPs have advantages like being a renewable source of protein but also have disadvantages like potentially high nucleic acid content.