Keratin degradation by bacteria and fungi isolated from a poultry farm and plumage

1. Poultry processing generates a large quantity of feather waste. Feathers are a rich source of keratin and could be used as a feather meal in the feed industry if the keratin is degraded using suitable micro-organisms.

2. In this study, keratin-degrading micro-organisms were isolated from a poultry farm. The predominant organisms were identified as Bacillus subtilis, Aspergillus flavus, A. fumigatus and Trychophyton sp.

3. The isolates were inoculated into feather medium and observed for keratin degradation by measuring the protein content, free amino acids and change in pH.

4. During feather degradation by B. subtilis, the concentration of soluble protein released to the medium increased gradually and reached the maximum (433 µg/ml) during d 7 of incubation and the pH increased from the initial 6.9 to 8.4 on d 9 of incubation. Similarly, the maximum protein content of 414 µg/ml and pH of 8.5 was observed for A. fumigatus on d 21 of incubation.

5. B. subtilis and A. fumigatus showed almost the same level of keratinase activity