Abstract: A novel Bacillus licheniformis MZK-3 isolated from poultry wastes produced growth associated extracellular keratinolytic enzyme in the feather powder broth medium. The optimum temperature and initial pH for growth and enzyme production were 40°C and 8.0. The keratinolytic activity in enzyme preparations increased about 30 and 12%, when 1% (w/v) molasses and 0.1% (w/v) NH4Cl was supplemented, respectively with the feather powder broth medium. The final 11-fold purified enzyme preparation showing the specific activity of 438.5 U mg•-1 was active and stable from pH 7.0 to 10.0 having the maximum activity at pH 9.0, thermostable at 30 to 50°C with 40°C as the optima. The half life of the enzyme at 50°C was 2 h and the activity was rapidly lost at 60°C or above. Experiment with protease inhibitors demonstrated that the enzyme was serine type as it was almost completely inhibited by PMSF. Both the crude and diluted purified enzyme preparations solubilized about 85% barbs of poultry feathers and 7% (w/w) of their native keratin after 12 h of incubation at 40°C, indicating that in practical application, this enzyme preparation is useful for promoting the hydrolysis of feather keratin and might have biotechnological potential involving keratin hydrolysis in the processing of poultry waste and leather industry.