O-Acetylserine is primarily used as a key intermediate in the biosynthesis of the amino acid cysteine in bacteria, fungi, and plants. It serves as a metabolic precursor in enzymatic reactions where sulfide is incorporated to form cysteine, making it essential in studies of sulfur metabolism and amino acid production. Due to its role in microbial metabolic pathways, O-acetylserine is widely used in biochemical research to investigate enzyme mechanisms, particularly those involving cysteine synthase and serine acetyltransferase. It is also employed in the development of biotechnological processes aimed at enhancing sulfur assimilation and cysteine production in crops, which can improve nutritional value and stress tolerance in plants. Additionally, it finds use in the formulation of specialized growth media for microbial cultures requiring defined metabolic precursors.