Effect of various poultry feather hydrolysates on the growth of indigenous keratinolytic strains

Abstract

Feather waste is a poultry by-product that is abundant, difficult to degrade, and creates an environmental problem. Feather protein is mainly composed of keratin, a structural protein with low digestibility. The effect of poultry feather meal prepared by NaOH as a Nitrogen source on the growth of the indigenous keratinolytic strain in the agar and the liquid medium was evaluated in this research. This study shows that all strains (Pseudomonas sp. PK-4, Bacillus cereus TD5B, and Bacillus cereus LS2B) can grow and produce clear zones around the colony. Medium containing 1% skim milk, commercial keratin, kampung, layer chicken feathers, and goose feathers were used to indicate that all strains could produce extracellular casein and keratinase enzymes. The strains can grow optimally in a liquid medium with feather hydrolysates, indicated by the increased turbidity (OD600) with a higher absorbance value. The highest growth occurred when strains grew with kampung chicken feather hydrolysate. Therefore, it can be concluded that the feather meals from local poultry feathers had potential as N-source for bacterial growth.