Bioutilization of poultry feather for keratinase production and its application in leather industry

Keratinase, a protease was produced from keratinolytic bacterium, Bacillus paralicheniformis MKU3, using poultry feather as substrate. Statistical analyses were carried out to enhance the activity of keratinase produced as a result of which enzyme activity was improved 6-fold yielding a maximum of 1872.5 U/ml and a specific activity of 1143.19 U/mg in 72 h. The keratinase produced was used to hydrolyze poultry feather waste which resulted in an almost 90% degradation by measurement of dry weight. Large scale production of keratinase was performed from 5-L to 500-L and it has been observed that an increase in the volume of bioreactor greatly improved the rate of production of keratinase along with a sharp decrease in production time. The keratinase produced was used to study dehairing on sheepskin and the efficiency was observed to be 100%. SEM and histochemical analysis on the skin confirmed efficient dehairing. The processed leather crust was further tested for physical strength and histochemistry wherein it has been proved that the quality of the leather crust produced is good. The environmental impact of the effluent produced as a result of dehairing was also assessed. (C) 2018 Elsevier Ltd. All rights reserved.