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.

Evaluation of by-products from agricultural, livestock and fishing industries as nutrient source for the production of proteolytic enzymes

“…Similarly, although feather meal exhibits a lower protein content, it still provides essential amino acids and other essential components that effectively support the growth and metabolism of bacteria, enabling them to efficiently produce proteolytic enzymes. These substrates function as valuable carbon and nitrogen sources for bacterial metabolism, facilitating the degradation of complex proteins into smaller peptides and amino acids, which can subsequently be utilized as essential nutrients for bacterial growth and the synthesis of enzymes [ 46 ]. Overall, the utilization of both soybean oil-cake and feather meal as cultivation media effectively promotes the production of proteolytic enzymes by providing the necessary nutritional components for bacterial growth and enzymatic activity ( Tables S1 and S2 ).…”