Isolation and characterization of a novel feather-degrading bacterial strain.

Feather waste, generated in large quantities as a byproduct of commercial poultry processing, is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Feather-degrading bacteria were isolated from a Brazilian poultry industrial waste. Among these isolates, a strain identified as kr2 was the best feather-degrading organism when grown on basal medium containing 10 g/L of native feather as a source of energy, carbon, and nitrogen. The isolate was characterized according to morphological characteristics and biochemical tests belonging to the Vibrionaceae family. Keratinolytic activity of this isolate was monitored throughout the cultivation of the bacterium on raw feather at different temperatures. The optimum temperature for growth was about 30 degrees C, at which maximum enzyme and soluble protein production were achieved. The enzyme had a pH and temperature optima of 8.0 and 55 degrees C, respectively.