A novel extracellular keratinase from Exiguobacterium sp. Dg1: enzyme production and dehairing application

In this research, we determined the optimum conditions for production of extracellular keratinase in Exiguobacterium sp DG1, and showed the possibility of application of the keratinase for sheep skin dehairing process. Strain DG1 showed the highest productivity of the keratinase activity during the growth in sheep hair meal (SHM) medium (pH 8) containing 10 g/L of SHM with aerobic incubation at 27°C for 48 hours. Moreover, dehairing process using an extracellular keratinase from strain DG1 decreased several index parameters in the treatment wastes. For example, in the treatment wastes using keratinase from strain DG1, COD and BOD values decreased drastically (82.1% and 73.7% respectively), compared to chemical dehairing process, and sulfide content was very low (less than 0.01 mg/L). These facts indicate that the extracellular keratinase from strain DG1 possesses a great potential of application for green leather tanning industry.