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BioMed Research International
Volume 2013 (2013), Article ID 175012, 14 pages
Research Article

Production and Characterization of Keratinolytic Protease from New Wool-Degrading Bacillus Species Isolated from Egyptian Ecosystem

1Protein Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, New Borg Al-Arab, P.O. Box. 21934, Alexandria, Egypt
2Botany and Microbiology Department, Faculty of Science (Boys), Al-Azhar University, Cairo, Egypt
3King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia

Received 2 December 2012; Revised 7 March 2013; Accepted 28 March 2013

Academic Editor: Periasamy Anbu

Copyright © 2013 Mohamed A. Hassan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Novel keratin-degrading bacteria were isolated from sand soil samples collected from Minia Governorate, Egypt. In this study, the isolates were identified as Bacillus amyloliquefaciens MA20 and Bacillus subtilis MA21 based on morphological and biochemical characteristics as well as 16S rRNA gene sequencing. B. amyloliquefaciens MA20 and B. subtilis MA21 produced alkaline keratinolytic serine protease when cultivated in mineral medium containing 1% of wool straight off sheep as sole carbon and nitrogen source. The two strains were observed to degrade wool completely to powder at pH 7 and 37°C within 5 days. Under these conditions the maximum activity of proteases produced by B. amyloliquefaciens MA20 and B. subtilis MA21 was 922 and 814 U/ml, respectively. The proteases exhibited optimum temperature and pH at 60°C and 9, respectively. However, the keratinolytic proteases were stable in broad range of temperature and pH values towards casein Hammerstein. Furthermore the protease inhibitor studies indicated that the produced proteases belong to serine protease because of their sensitivity to PMSF while they were inhibited partially in presence of EDTA. The two proteases are stable in most of the used organic solvents and enhanced by metals suggesting their potential use in biotechnological applications such as wool industry.