products can be fermented to use as food for animals, especially ruminants. fungi have been employed to break down cellulosic wastes to increase protein content and improve in vitro digestibility. precision fermentation precision fermentation is an approach to manufacturing specific functional products which intends to minimise the production of unwanted by-products through the application of synthetic biology, particularly by generating synthetic "cell factories" with engineered genomes and metabolic pathways optimised to produce the desired compounds as efficiently as possible with the available resources. precision fermentation of genetically modified microorganisms may be used to manufacture proteins needed for cell culture media, providing for serum-free cell culture media in the manufacturing process of cultured meat. a 2021 publication showed that photovoltaic-driven microbial protein production could use 10 times less land for an equivalent amount of protein compared to soybean cultivation.