Production of feather protein hydrolysate by keratinolytic bacterium Vibrio sp. kr2

A feather protein hydrolysate was produced using the keratinolytic bacterium Vibrio sp. strain kr2. Complete feather degradation was observed in medium containing up to 60 g L(-1) raw feathers. Cultivation on 40, 60 or 80 g L(-1) feathers for five days resulted in similar amounts of soluble protein, reaching maximum values around 2.5 g L(-1). Maximum yields of soluble protein were achieved at 30 degrees C and initial pH ranging from 6.0 to 8.0. Strain kr2 was effective in producing keratin hydrolysate from chicken feathers. Bacterial feather hydrolysate has the potential for utilization as an ingredient in animal feed or as organic fertilizer, thereby reducing the environmental impact of feather waste from the poultry industry.