Effective feather degradation and keratinase production by Bacillus pumilus GRK for its application as bio-detergent additive

An effecient feather-degrading bacterium was isolated from poultry dumping yard and identified as Bacillus pumilus GRK based on 16 S rRNA sequencing. Complete feather degradation (98.3 +/- 1.52%) with high keratinase production (373 +/- 4 U/ml) was observed in 24 h under optimized conditions (substrate 1% (w/w); inoculum size 4% (v/v); pH 10; 200 rpm at 37 degrees C) with feathers as sole carbon and nitrogen source in tap water. The fermented broth was enriched with amino acids like tryptophan (221.44 mu g/ml), isoleucine (15.0 mu g/ml), lysine (10.81 mu g/ml) and methionine (7.24 mu g/ml) suggesting its potential use as feed supplement. The keratinase produced was a detergent stable serine protease and its activity was further enhanced by Ca+2 and Mg+2. Bacillus pumilus GRK keratinase was successfully utilised as bioadditive in detergent formulations for removing the blood stains from cloth without affecting its fiber and texture. (C) 2017 Elsevier Ltd. All rights reserved.