Keratinases are very widespread in the microbial world and they can be identified from microorganisms of the three domains: Eukarya, Bacteria and Archea. These microorganisms have been isolated from the most distinct soil habitats, including aerobic and anaerobic environments. Therefore, microbial keratinases present a great diversity in their biochemical and biophysical properties. In addition to these species, keratinase production has been associated to an increasing number of bacteria. The biochemical properties of microbial keratinases may be diverse depending on the producer microorganism. Most of the microbial keratinases are alkaline or neutral showing optima pH ranging 7.5-9.0. The properties of microbial keratin degrading enzymes appear to differ according to the producing species of microorganism. Proteolytic enzymes are largely used in the industry for biotechnological applications involving the hydrolysis of protein substrates. However microbial keratinases are considered as promising biocatalysts for several pharmaceutical and biomedical applications. Bioconversion of Keratin-rich materials into amino acids, peptides and soluble proteins by keratinases is possible. The extracellular keratinase isolated from different microorganisms has a great potential for biotechnological applications. Based on the biochemical characterization, the keratinase producing species were analysed and reported for further classification of its application to the environment.