title: A novel keratinase from Bacillus tequilensis strain Q7 with promising potential for the leather bating process.
abstract: The present paper reports on the purification and characterization of an extracellular keratinase (KERQ7) newly purified from Bacillus tequilensis Q7. Pure protein was obtained after ammonium sulfate fractionation (30-60%), followed by Mono S Sepharose cation-exchange chromatography. MALDI-TOF/MS analysis revealed that the purified enzyme was a monomer with a molecular mass of 28,355.07-Da. The sequence of the 21 N-terminal residues of KERQ7 showed high homology with those of Bacillus keratinases. Optimal activity was achieved at pH 7 and 30°C. KERQ7 was completely inhibited by PMSF and DFP, which suggests that it belongs to the serine keratinase family. KERQ7 displayed higher levels of hydrolysis and catalytic efficiency than Basozym(®) CS 10, Koropon(®) SC 5K, and Pyrase(®) 250 MP. The kerQ7 gene encoding KERQ7 was cloned, sequenced, and expressed in Escherichia coli BL21(DE3)pLysS. The biochemical properties of the extracellular purified recombinant enzyme (rKERQ7) were similar to those of native KERQ7. The deduced amino acid sequence showed strong homology with other Bacillus keratinases. The highest sequence identity value (97%) was obtained with KERUS from Brevibacillus brevis US575, with only 7 aa of difference. These properties make KERQ7 a potential promising and eco-friendly enzymatically enhanced process for animal hide bating in the leather processing industry.
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, P.O. Box 1177, Sfax 3018, Tunisia.
authors.forename: Nadia
authors.initials: N
authors.lastname: Zaraî Jaouadi
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, P.O. Box 1177, Sfax 3018, Tunisia.
authors.forename: Hatem
authors.initials: H
authors.lastname: Rekik
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, P.O. Box 1177, Sfax 3018, Tunisia.
authors.forename: Mouna
authors.initials: M
authors.lastname: Ben Elhoul
authors.affiliation: Laboratory of Natural Products Chemistry and Biomolecules (LNPCB), University of Blida, 1, Road of Soumaâ, P.O. Box 270, 09000 Blida, Algeria; National Centre for Research and Development of Fisheries and Aquaculture (CNRDPA), 11, Bd Amirouche PO Box 67, Bou Ismaïl, 42415 Tipaza, Algeria.
authors.forename: Fatma
authors.initials: F
authors.lastname: Zohra Rahem
authors.affiliation: National Leather and Shoe Center (CNCC), 17 Road of Leather, Z.I. Sidi Rezig, 2033 Mégrine, Ben Arous, Tunisia.
authors.forename: Chiraz Gorgi
authors.initials: CG
authors.lastname: Hila
authors.affiliation: National Leather and Shoe Center (CNCC), 17 Road of Leather, Z.I. Sidi Rezig, 2033 Mégrine, Ben Arous, Tunisia.
authors.forename: Houda Slimene
authors.initials: HS
authors.lastname: Ben Aicha
authors.affiliation: Laboratory of Natural Products Chemistry and Biomolecules (LNPCB), University of Blida, 1, Road of Soumaâ, P.O. Box 270, 09000 Blida, Algeria; National Centre for Research and Development of Fisheries and Aquaculture (CNRDPA), 11, Bd Amirouche PO Box 67, Bou Ismaïl, 42415 Tipaza, Algeria.
authors.forename: Abdelmalek
authors.initials: A
authors.lastname: Badis
authors.affiliation: National Leather and Shoe Center (CNCC), 17 Road of Leather, Z.I. Sidi Rezig, 2033 Mégrine, Ben Arous, Tunisia.
authors.forename: Abdessatar
authors.initials: A
authors.lastname: Toumi
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, P.O. 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, P.O. Box 1177, Sfax 3018, Tunisia. Electronic address: bassem.jaouadi@yahoo.fr.
authors.forename: Bassem
authors.initials: B
authors.lastname: Jaouadi
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D001407:Bacillus / Q000201:enzymology*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D010447:Peptide Hydrolases; C035855:keratinase
keywords: Bacillus tequilensis; Keratinases; Leather processing