Degradation of feather keratin by culture filtrates of Streptomyces fradiae

Abstract

Treatment of milled defatted capon feathers with filtrates of Streptomyces fradiae ATCC 10745 that had been concentrated 20 times showed that the most keratin degradation in 0.5 h occurred at pH 8.0 and 60 °C. If assay time was extended, however, a decrease in reaction rate occurred and appeared to result from keratinase instability at elevated temperatures. Exposure of commercial feather meal to unconcentrated culture filtrates for 15 h produced greatest degradation at 50 °C.