Keratin is a protein that acts as the key structural material in making up hair, nails, feathers, scales etc. It protects epithelial cells from damage or stress. Degradation of these keratin rich materials in nature is done by specific bacteria and other microorganisms that produce an enzyme called Keratinase. The present study aimed at the isolation, optimization and PCRassisted identification of Keratinase producing bacteria associated with chicken feathers. Keratinase producing bacteria were isolated from soil samples collected from chicken farms. The isolated bacteria were screened primarily on skimmed milk media and the colonies indicating keratinolytic behaviour were classified morphologically, microscopically and biochemically. The potential strains were then subjected to enzyme production in order to measure the enzyme activity. The effects of temperature, pH and period of incubation on the enzyme activity were also studied to identify the optimal range to produce the enzyme. The maximum enzyme activity was observed for the isolate VITSJ01 at an optimum pH of 5 and 37o C temperature. Further the potential strain was identified as Bacillus velezensis by 16S rDNA sequencing. The isolate was then successfully purified, sequenced and analysed by NCBI-BLAST for similar search. Thus, the purification of microbial keratinase from soil samples could be effectively utilized for degrading feather keratin and feathers can be converted to feedstuffs, fertilizers, glues and films.

Keratin waste has become an increasingly serious environmental and health hazard. Keratin waste is mainly composed of keratin protein, which is one of the most difficult polymers to break down in nature and is resistant to many physical, chemical, and biological agents. With physical and chemical methods being environment damaging and costly, microbial degradation of keratin using keratinase enzyme is of great significance as it is both environment friendly and costeffective. The aim of this study was to extract and purify keratinase from bacterial species isolated from the soil. Among the organisms, an isolate of Bacillus velezensis, coded as MAMA could break down chicken feathers within 72 hours (h). The isolated strain produced significant levels of keratinase in mineral salt medium by supplying chicken feathers as the sole source of nitrogen and carbon. Feather deterioration was observed with the naked eye, and enzyme activity was evaluated using a spectrophotometric assay. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymography results revealed that the keratinase protein produced by Bacillus velezensis had a molecular weight between 40 and 55 kilodalton (kDa).