Microbial keratinases: characteristics, biotechnological applications and potential

Keratinases are a group of proteolytic enzymes that can catalyse the cleavage and hydrolysis of the highly stable and fibrous proteins: keratins. A diverse range of microorganisms, including fungi, actinomycetes and bacteria, have been reported to produce keratinases that have biotechnological applications and potential. These keratinases have been usefully applied in agricultural, pharmaceutical, leather and textile processes as well as within environmentally friendly waste management solutions. Potential uses of keratinases include the fields of biomedicine, cosmetics, biological control and the generation of green energy. Herein we aim to provide an overview of the properties of this group of versatile enzymes, including the mechanisms of keratin degradation. The diversity of microbial sources of keratinases is discussed and the optimisation of keratianse production examined. We conclude with an assessment of the established biotechnological applications of keratinases in different industries and current research that highlights other promising potential uses