Identification, Characterization, and Immobilization of an Organic Solvent-Stable Alkaline Hydrolase (PA27) from Pseudomonas aeruginosa MH38

Molecules

Eunjin Jang¹  Bum Han Ryu¹ 

[1] Department of Applied Chemistry and Biological Engineering, College of Engineering, Ajou University, Suwon 443-749, Korea;

关键词: PA27;    hydrolase;    immobilization;    stability;    electron microscopy;   

DOI  :  10.3390/molecules190914396

来源: mdpi

【 摘 要 】

An organic solvent-stable alkaline hydrolase (PA27) from Pseudomonas aeruginosa MH38 was expressed, characterized, and immobilized for biotechnological applications. Recombinant PA27 was expressed in Escherichia coli as a 27 kDa soluble protein and was purified by standard procedures. PA27 was found to be stable at pH 8–11 and below 50 °C. It maintained more than 80% of its activity under alkaline conditions (pH 8.0–11.0). Furthermore, PA27 exhibited remarkable stability in benzene and n-hexane at concentrations of 30% and 50%. Based on these properties, immobilization of PA27 for biotechnological applications was explored. Scanning electron microscopy revealed a very smooth spherical structure with numerous large pores. Interestingly, immobilized PA27 displayed improved thermal/chemical stabilities and high reusability. Specifically, immobilized PA27 has improved thermal stability, maintaining over 90% of initial activity after 1 h of incubation at 80 °C, whereas free PA27 had only 35% residual activity. Furthermore, immobilized PA27 showed higher residual activity than the free enzyme biocatalysts against detergents, urea, and phenol. Immobilized PA27 could be recycled 20 times with retention of ~60% of its initial activity. Furthermore, macroscopic hydrogel formation of PA27 was also investigated. These characteristics make PA27 a great candidate for an industrial biocatalyst with potential applications.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.