Chicken feathers (CF) are a significant type of residual waste produced by the meat processing industry. Prolonged accumulation of such a leftover CF could be a serious problem for solid waste management. Consequently, CF can be exploited for widespread production of keratinaceous around the world that calls for their justifiable use. CF mostly consist of keratins, which are widely applied in a variety of industries. Since CF has potent resistance to protease breakdown, untreated feathers could create environmental pollution. Studies revealed that instated of treating the resistant pollutant (keratin), microbial digestion of keratin waste can provide the appreciable opportunity to obtain a commercially significant enzyme, keratinase. This review study provides a broad overview of the potential applications of several bacterial and fungi species for the keratinase synthesis employing keratinaceous wastes as substrates. Additionally, a briefly outlook has been provided on the exploitation of microbial keratinases with its biochemical and functional properties in the synthesis of cattle feed, food, nutrition, detergents, organic fertilizers as well as leather, cosmetics, and medicinal products. © 2025 Elsevier B.V., All rights reserved.