Table of Contents Author Guidelines Submit a Manuscript
International Journal of Microbiology
Volume 2013 (2013), Article ID 608321, 7 pages
Research Article

Efficient Degradation of Feather by Keratinase Producing Bacillus sp.

Department of Applied Microbiology, Sri Padmavati Mahila Visvavidyalayam, Tirupati 517502, Andhra Pradesh, India

Received 25 July 2013; Accepted 18 September 2013

Academic Editor: Todd R. Callaway

Copyright © 2013 P. Jeevana Lakshmi 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.


Keratinase producing microorganisms are being increasingly utilized for degradation and recycling of poultry feather waste. Two native strains BF11 (Bacillus subtilis) and BF21 (Bacillus cereus) degrading keratin completely were characterized. The native strains produced more than 10 KU/mL of enzyme. Strain improvement resulted in isolation of MBF11 and MBF21 from BF11 and BF21 isolates, respectively. Optimization of nutritional and physical parameters of these MBF isolates at laboratory scale increased the overall keratinase activity by 50-fold resulting in a yield of 518–520 KU/mL. Fermentation media designed with starch as carbon source and soya bean meal as nitrogen source supported high levels of enzyme production. The optimum conditions for enzyme production were determined to be pH 8.5 and temperatures of 45–55°C for MBF11 and 37°C for MBF21, respectively. Culture filtrate showed a significant increase in the amounts of cysteine, cystine, methionine, and total free amino acids during the fermentation period. The ratio of organic sulphur concentration was also considerably higher than that of the inorganic sulphate in the culture filtrate suggesting the hydrolysis of disulphide by the isolates.