Isolation of chrysosporium indicum from poultry soil for keratinase enzyme, its purification and partial characterization

Abstract

Keratinases are produced by microorganisms as fungi, actinomycetes and bacteria and have the capacity to degrade tough insoluble keratin proteins, including feathers. Feathers are waste produced from the poultry industry worldwide and accumulated as solid waste. Therefore, keratinolytic fungal strains Chrysosporium indicum were isolated by hair baiting method from poultry farm soil of Punjab, India. Isolated C. indicum were screened for proteolytic activity on skimmed milk agar. Field Emission Scanning Electron Microscopy (FeSEM) analysis confirmed morphological characters as C. indicum. Fourier transform infrared spectroscopy analysis was studied for the structural and mechanism analysis of feather degraded during keratinase production. Keratinase enzyme was purified 48.03% recovery by ammonium sulphate precipitation, dialysis for desalting and chromatography. Diethylaminoethyl sepharose (DEAE sepharose) and Sephadex-G75 column were used to perform chromatography and partial characterization of the keratinase for temperature, pH, and substrate. The maximum keratinase activity was observed at 500C, at pH 10. The maximum enzyme activity of 289.1 U/ml was observed with keratin powder as substrate and minimum enzyme activity 67.1 U/ml with keratin azure. This is the first report on the purification and characterization of keratinase by C. indicum using DEAE sepharose as affinity chromatography for the purification of the keratinase enzyme.