CHARACTERIZATION OF A MICROBIAL KERATINASE WITH LEATHER DEHAIRING AND FEATHER WASTE MANAGEMENT POTENTIAL - H. Batool; M. W. Akhthar; M. Saleem1 (Journal of Animal and Plant Sciences, 2020)
The aim of the study was purification and biochemical characterization of a keratinase enzyme from indigenous microorganism and its promising potential biotechnological applications. The increasing demand of keratinases in different industrial sectors calls for the need of more robust and stable keratinases with potential industrial applications. Keratinase produced by Bacillus D2 strain was purified by gel filtration and Q-Sepharose chromatograph. The enzyme showed a specific activity of 525 U/mg with overall recovery of 23.8%. Molecular size of purified enzyme after SDS-PAGE and zymogram was found 40 kDa. Purified keratinase had an optimal pH 8.5 and optimal temperature 50oC. Enzyme displayed pH stability in pH range of 7.5–9.0 and thermal stability up to 60oC. Amongst reducing agents, sodium sulfite and dithiothreitol (DTT) reduced relative activity however; SDS increased activity at 5 mM concentration. Keratinase enzyme was found solvent stable at 0.5% and 1% concentration. MgCl2 enhanced activity up to 108% and 104% at 5 and 10 mM concentrations, respectively. Enzymatic treatment of goat skin and cow hide resulted in dehairing and removal of scud and keratin skin layer resultantly smooth intact skin surface was observed. However, conventionally treated hides produced dark and hard skin surface due to partial elimination of keratin layer. Potential of Bacillus strain for conversion of feather keratin waste in to valuable feather meal suggests its usefulness in poultry industry and eventually reducing environmental pollution hazards.
Keywords: journal article; Characterization; Feather waste; Keratinase; Leather dehairing; Protein purification