Novel serine keratinase from Caldicoprobacter algeriensis exhibiting outstanding hide dehairing abilities

作者：Bouacem Khelifa; Bouanane Darenfed Amel^*; Jaouadib Nadia Zarai; Joseph Manon; Hacene Hocine; Ollivier Bernard; Fardeau Marie Laure; Bejar Samir; Jaouadi Bassem^*

来源：International Journal of Biological Macromolecules, 2016, 86: 321-328.

DOI：10.1016/j.ijbiomac.2016.01.074

• Caldicoprobacter algeriensis
• Keratinase
• Leather processing industry

The current paper reports on the purification of an extracellular thermostable keratinase (KERCA) produced from Caldicoprobacter algeriensis strain TH7C1(T), a thermophilic, anaerobic bacterium isolated from a hydrothermal hot spring in Algeria. The maximum keratinase activity recorded after 24-h of incubation at 50 degrees C was 21000 U/ml. The enzyme was purified by ammonium sulfate precipitation-dialysis and heat treatment (2 h at 50 degrees C) followed by UNO Q-6 FPLC anion exchange chromatography, and submitted to biochemical characterization assays. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer with a molecular mass of 33246.10 Da. The sequence of the 23 N-terminal residues of KERCA showed high homology with those of bacterial keratinases. Optimal activity was achieved at pH 7 and 50 degrees C. The enzyme was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP), which suggests that it belongs to the serine keratinase family. KERCA displayed higher levels of hydrolysis and catalytic efficiency than keratinase KERQ7 from Bacillus tequilensis strain Q7. These properties make KERCA a potential promising and eco-friendly alternative to the conventional chemicals used for the dehairing of goat, sheep, and bovine hides in the leather processing industry.

• 出版日期2016-5