title: Novel serine keratinase from Caldicoprobacter algeriensis exhibiting outstanding hide dehairing abilities.
abstract: 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 °C was 21000 U/ml. The enzyme was purified by ammonium sulfate precipitation-dialysis and heat treatment (2h at 50 °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 °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.
authors.affiliation: Laboratory of Cellular and Molecular Biology (LCMB), Microbiology Team, Faculty of Biological Sciences, University of Sciences and Technology of Houari Boumediene (USTHB), PO Box 32, El Alia, Bab Ezzouar, 16111 Algiers, Algeria; Laboratory of Microbial Biotechnology and Engineering Enzymes (LMBEE), Centre of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour Km 6, PO Box 1177, Sfax 3018, Tunisia; Aix Marseille Université, IRD, Université de Toulon, CNRS, Mediterranean Institute of Oceanography (MIO), UM 110, 163 Avenue of Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Khelifa
authors.initials: K
authors.lastname: Bouacem
authors.affiliation: Laboratory of Cellular and Molecular Biology (LCMB), Microbiology Team, Faculty of Biological Sciences, University of Sciences and Technology of Houari Boumediene (USTHB), PO Box 32, El Alia, Bab Ezzouar, 16111 Algiers, Algeria; Aix Marseille Université, IRD, Université de Toulon, CNRS, Mediterranean Institute of Oceanography (MIO), UM 110, 163 Avenue of Luminy, 13288 Marseille Cedex 9, France. Electronic address: amelbouanane@gmail.com.
authors.forename: Amel
authors.initials: A
authors.lastname: Bouanane-Darenfed
authors.affiliation: Laboratory of Microbial Biotechnology and Engineering Enzymes (LMBEE), Centre of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour Km 6, PO Box 1177, Sfax 3018, Tunisia.
authors.forename: Nadia
authors.initials: N
authors.lastname: Zaraî Jaouadi
authors.affiliation: Aix Marseille Université, IRD, Université de Toulon, CNRS, Mediterranean Institute of Oceanography (MIO), UM 110, 163 Avenue of Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Manon
authors.initials: M
authors.lastname: Joseph
authors.affiliation: Laboratory of Cellular and Molecular Biology (LCMB), Microbiology Team, Faculty of Biological Sciences, University of Sciences and Technology of Houari Boumediene (USTHB), PO Box 32, El Alia, Bab Ezzouar, 16111 Algiers, Algeria.
authors.forename: Hocine
authors.initials: H
authors.lastname: Hacene
authors.affiliation: Aix Marseille Université, IRD, Université de Toulon, CNRS, Mediterranean Institute of Oceanography (MIO), UM 110, 163 Avenue of Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Ollivier
authors.affiliation: Aix Marseille Université, IRD, Université de Toulon, CNRS, Mediterranean Institute of Oceanography (MIO), UM 110, 163 Avenue of Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Fardeau
authors.affiliation: Laboratory of Microbial Biotechnology and Engineering Enzymes (LMBEE), Centre of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour Km 6, PO Box 1177, Sfax 3018, Tunisia.
authors.forename: Samir
authors.initials: S
authors.lastname: Bejar
authors.affiliation: Laboratory of Microbial Biotechnology and Engineering Enzymes (LMBEE), Centre of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour Km 6, PO Box 1177, Sfax 3018, Tunisia. Electronic address: bassem.jaouadi@cbs.rnrt.tn.
authors.forename: Bassem
authors.initials: B
authors.lastname: Jaouadi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D000068536:Bacillota / Q000201:enzymology* / Q000302:isolation & purification; D006197:Hair / Q000378:metabolism*; D045482:Hot Springs / Q000382:microbiology; D006868:Hydrolysis; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D019163:Reducing Agents / Q000494:pharmacology; D012694:Serine / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D008670:Metals; D019163:Reducing Agents; D012694:Serine; D010447:Peptide Hydrolases; C035855:keratinase
keywords: Caldicoprobacter algeriensis; Keratinase; Leather processing industry