ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Immobilization of protease on chitosan–silica gel beads for high detergent and surfactant stability and high tolerance against metallic ions and organic solvents

Volkan Karakurt and Canan Gulmez Samsa

Department of Bioengineering and Sciences, Graduate Education Institute, Igdir University, Igdir, Türkiye

E-mail: canan_glm@hotmail.com

Received: 22 September 2022  Accepted: 31 January 2023

Abstract:

Proteases are of the crucial industrial enzymes due to their notable functions. However, they can be further functionalized through immobilization and then their immobilized structures might be successfully employed in order to meet the industrial interest. Along with the present study, we immobilized protease onto chitosan–silica gel beads via glutaraldehyde-mediated cross-linking and then assayed its potential uses for detergent. In this context, a series of biochemical analysis was performed. Accordingly, the findings of the present study revealed that the optimum pH of the free and immobilized protease were found as 7–10, and the optimum temperatures were noted as 40 and 50 °C, respectively. After five cycles of repeated uses, the immobilized protease with a high encapsulation yield (96%) retained almost 50% of its original activity (94%) at 4 °C. In comparison with the free protease, the immobilized protease exhibited higher activities on metal ions and its activities were augmented more than 18% in the presence of 5 mM Mg²⁺ for 1 h. Also, the relevant activities increased by 4.4-, 3.4- and 6.5-fold in the ethanol, xylene and Tween 80, respectively. Again, in relation to the free protease, immobilized protease was more stable in some commercial laundry detergents (Omo, Perwoll and Bingo). Those findings suggested that immobilized protease might be successfully applied in high-alkalinity and high-temperature washing conditions. Finally, owing to the superior characteristics, the immobilized protease can be evaluated in detergent industry.

Keywords: Protease; Immobilization; Gel bead; Detergent; Surfactant

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02709-3

Chemical Papers 77 (6) 3361–3372 (2023)