Production, purification and biochemical characterization of a novel detergent-stable serine alkaline protease from Bacillus safensis strain RH12

• Published in: International journal of biological macromolecules 2019-01, Vol.121, p.1227-1239
• Main Authors: Rekik, Hatem, Zaraî Jaouadi, Nadia, Gargouri, Fares, Bejar, Wacim, Frikha, Fakher, Jmal, Najah, Bejar, Samir, Jaouadi, Bassem
• Format: Article
• Language: English
• Subjects: Bacillus - enzymology; Bacillus safensis; Bacterial Proteins - antagonists & inhibitors; Bacterial Proteins - biosynthesis; Bacterial Proteins - isolation & purification; Bacterial Proteins - metabolism; Calcium - pharmacology; Coloring Agents - metabolism; Cotton Fiber; Detergent; Detergents - pharmacology; Drug Interactions; Endopeptidases - biosynthesis; Endopeptidases - isolation & purification; Endopeptidases - metabolism; Enzyme Inhibitors - pharmacology; Enzyme Stability - drug effects; Hydrogen-Ion Concentration; Kinetics; Offshore oil field; Phylogeny; Polymers - pharmacology; Protease; Wash performance
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2018.10.139

A novel extracellular protease (SAPRH) was hyper-produced (9000 U/mL) from Bacillus safensis RH12, a newly isolated enzyme from a Tunisian offshore oil field. The enzyme was purified to homogeneity, using salt-precipitation, heat-treatment and FPLC anion-exchange chromatography. The purified enzyme was a monomer of molecular mass of ~28 kDa. The NH2-terminal 23 amino-acid sequence of SAPRH showed high homology with those of Bacillus-proteases. SAPRH displayed optimal activity at pH 9 and 60 °C. It was strongly inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP), indicating that it belongs to the serine-proteases family. Moreover, SAPRH was extremely stable at a broad range of temperature and pH retaining 85% of its activity at 50 °C and 75% at pH 11. The enzyme exhibited excellent stability and compatibility with surfactants and commercial detergents, revealing 90% stability with SDS and 100% stability with Class commercial laundry detergent. One of the most distinctive properties is its catalytic efficiency, which is higher than that of Alcalase 2.5 L, typeDX (commercial enzyme) and SAPB from B. pumilus CBS. Interestingly, the results of the wash performance analysis demonstrated considerably good de-staining at 40 °C for 30 min with low supplementation (500 U/mL). Accordingly, such a protease could be considered as a good detergent-additive in detergent industry. •A novel extracellular protease (SAPRH) from Bacillus safensis strain RH12 was studied.•SAPRH with a molecular mass of ~28 kDa was purified and biochemically characterized.•The optimum pH and temperature values for activity were pH 9 and 60 °C, respectively.•SAPRH displayed higher enzymatic performance than Alcalase 2.5 L, type DX and SAPB.•SAPRH is a future potential candidate as bio-additive for detergent formulations.