This study was performed to investigate the nutritional conditions controlling keratinase activity in Bacillus megaterium F7-1. B. megaterium F7-1 produced keratinase using chicken feather as a sole source of carbon, nitrogen and sulfur. Addition of the feather medium with glucose enhanced keratinase production (68.9 U/ml), compared to control without glucose (63.2 U/ml). The synthesis of keratinase was repressed by addition of NH4Cl in B. megaterium F7-1. The highest keratinase production (70.9 U/ml) was obtained with the feather medium containing glucose and MgSO4·7H2O. Keratinase was produced in the absence of feather (4.9 U/ml), indicating its constitutive synthesis. Feather degradation resulted in free SH group formation. B. megaterium F7-1 effectively degraded chicken feather meal (86%), whereas duck feather, human nail, human hair and sheep wool displayed relatively low degradation rates (8-34%).

Abstract
 1. Introduction
 2. Materials and Methods
  2.1. Microorganism and culture conditions
  2.2. Feather keratin preparation
  2.3. Keratinase assay
  2.4. Analytical methods
 3. Results and Discussion
 4. Conclusion
 References

• Jin-Ha Jeong(Department of Life Science and Environmental Biochemistry, Pusan National University)
• Na-Ri Lee(Department of Life Science and Environmental Biochemistry, Pusan National University)
• Young-Dong Jeon(Department of Life Science and Environmental Biochemistry, Pusan National University)
• Jeong-Do Kim(Department of Life Science and Environmental Biochemistry, Pusan National University)
• Ki-Hyun Park(Department of Life Science and Environmental Biochemistry, Pusan National University)
• Hong-Joo Son(Department of Life Science and Environmental Biochemistry, Pusan National University) Corresponding Author
• Geun-Tae Park(Research and University-Industry Cooperation, Pusan National University)