Purification and Biochemical Characterization of a Novel Thermostable Serine Protease from Geobacillus sp. GS53

Abstract

Proteases account for approximately 60% of the enzyme market in the world, and they are used in various industrial applications including the detergent industry. In this study, production and characterization of a novel serine protease of thermophilic Geobacillus sp. GS53 from Balçova geothermal region, İzmir, Turkey, were performed. The thermostable protease was purified through ammonium sulfate precipitation and anion-exchange chromatography. The results showed that the protease had 137.8 U mg?1 of specific activity and optimally worked at 55 oC and pH 8. It was also active in a broad pH (4–10) and temperature (25–75 °C) ranges. The protease was highly stable at 85 °C and demonstrated relative stability at pH 4, 7, and 10. Also, the enzyme had high stability against organic solvents and surfactants; enzyme relative activity did not decrease below 81% upon preincubation for 10 min. Ca2+, Cu2+, and Zn2+ ions slightly induced protease activity. The protease was highly specific to casein, skim milk, Hammerstein casein, and BSA substrates. These results revealed that the protease might have a potential effect in a variety of industrial fields, especially the detergent industry, because of its high thermostability and stability to surfactants. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.