Study of keratinolytic properties of bacteria isolated from poultry wastes

Keratin is a complex protein that constitutes a major component of feathers, hair and nails. The keratin rich waste materials, such as poultry wastes pose a significant environmental challenge. The aim of this study is to isolate and screen keratinolytic bacteria from soil where poultry wastes are dumped, with the potential for applications in bioremediation. Soil samples were collected from areas surrounding poultry farms where feather waste was excessively discarded. The samples were first processed, serially diluted and then plated onto nutrient agar plates. Then the colonies were cultured on skimmed milk agar plates and were observed for the proteolytic activity in the form of clear zones. The isolates which showed clear zones on the skimmed agar plates were then processed and inoculated into modified liquid basal medium supplemented with chicken feather. A total of 5 bacterial isolates were capable of degrading the feathers in 20 days of incubation. These isolates which were able to degrade the feather were then inoculated onto selective media (feather meal agar) containing keratin as the sole carbon source to confirm their keratinolytic activity. Biochemical characterization was carried out for the 5 bacterial isolates. The results of these tests indicated that the 5 bacterial isolates might belong to Bacillus spp, Psuedomonas spp and Microbacterium spp. Thus, these novel keratinolytic bacterial isolates have potential use in processes involving keratin hydrolysis.