Characterization of alkaline keratinase of Bacillus licheniformis strain HK-1 from poultry waste

KORKMAZ H. , HUR H., Dincer S.

ANNALS OF MICROBIOLOGY, cilt.54, sa.2, ss.201-211, 2004 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 54 Konu: 2
  • Basım Tarihi: 2004
  • Sayfa Sayıları: ss.201-211


A feather-degrading Bacillus licheniformis strain HK-1 was isolated from poultry waste. High keratinolytic activity was observed when it was cultured on broth containing native feather powder. The B. licheniformis strain HK-1 was identified on morphological and biochemical tests and 16S rRNA sequencing. Maximum keratinase production was observed at 50 degreesC and initial pH of 8.0. The enzyme was active over a wide range of pH (with optimum 11.0) and temperature (with optimum 60 degreesC) and was relatively heat stable (up to 60 degreesC). The enzyme molecular weight was estimated about 46 kDa by SDS-PAGE. Complete feather degradation was achieved at 60 degreesC in 3 days incubation in culture supernatant. Keratinolytic activity was partially inhibited by EDTA, 1,10-phenanthroline, NaCl and PMSF. It was however notably inhibited by ZnCl2. Keratinolytic activity was on the other hand increased by DMSO, TritonX-100, SIDS, CaCl2 and sodium sulphite. The bacterium seems to present potential use for biotechnological processes involving keratin hydrolyses.