Production of Keratinase by Free and Immobilized Cells of Bacillus halodurans Strain PPKS-2: Partial Characterization and Its Application in Feather Degradation and Dehairing of the Goat Skin

• Published in: Applied biochemistry and biotechnology 2010-04, Vol.160 (7), p.1909-1920
• Main Authors: Prakash, Pathange, Jayalakshmi, Senigala K, Sreeramulu, Kuruba
• Format: Article
• Language: English
• Subjects: Alkalinity; Animals; Bacillus - classification; Bacillus - cytology; Bacillus - isolation & purification; Bacillus - metabolism; Bacillus halodurans; Biochemistry; Biodegradation; Biological and medical sciences; Biotechnology; Cells; Cells, Immobilized - metabolism; Chemistry; Chemistry and Materials Science; culture media; degradation; dehairing; Detergents; EDTA (chelating agent); Enzyme Activation; feathers; Feathers - metabolism; Fermentation; food processing wastes; Fundamental and applied biological sciences. Psychology; General aspects; Goats; Hair - metabolism; Hair Removal - methods; hides and skins; hydrolysates; Immobilization techniques; immobilized cells; immobilized enzymes; keratinase; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; optimization; Peptide Hydrolases - biosynthesis; Peptide Hydrolases - chemistry; Peptide Hydrolases - metabolism; poultry; rice; Skin; Skin - chemistry; Skin - metabolism; Sodium chloride; sodium sulfite; solid state fermentation; Solid waste management; Solid wastes; soy flour; Soybeans; strains; Waste management
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-009-8702-0

An extremely alkaliphilic bacterial strain, Bacillus sp. PPKS-2, was isolated from rice mill effluents and screened for the production of extracellular keratinase. The maximum production of keratinase occurred after 48 h in shaking culture at pH 11.0 and 37 °C in a medium containing 0.5% soybean flour. The strain grew and produced alkaline keratinase using chicken feather and horn meal as the sole source of carbon and nitrogen. An addition of 0.1% soybean flour or feather hydrolysate and sodium sulfite to feather medium increased the production and complete solubilization of feather took place within 5 days under solid-state fermentation conditions. The partially purified enzyme displayed maximum activity at pH 11.0 and 60 °C in a broad range of NaCl, 0-16%, and was not inhibited by sodium dodecyl sulfate (10%), ethylenediaminetetraacetic acid (10 mM), H₂O₂ (15%), and other commercial detergents. Immobilization of the whole cells proved to be useful for continuous production of keratinase and feather degradation. The enzyme was effectively used to remove hair from goat hide. The strain PPKS-2 can be effectively used for solid waste management of poultry feather in submerged as well as solid-state fermentation.