Preliminary study of encapsulation to improve stability of ALDH of Wickerhamomyces anomalus

Abstract

Objective: This study aimed to improve the stability Wickerhamomyces anomalus aldehyde dehydrogenase in cold storage and gastrointestinal environment, so as to develop products that reduce active aldehydes in gastrointestinal tract. Methods: ALDH was extracted from 6 Wickerhamomyces anomalus strains with the highest activity of aldehyde dehydrogenase (ALDH), and encapsulated by sodium alginate and calcium chloride method. The stability of ALDH by embedding was studied in cold storage and simulated gastrointestinal environment. Results: The specific activity of ALDH produced by W. anomalus J3, J7, J8, J9, J12 and J18 ranged from 86.77 U/mg to 482.14 U/mg, and that of J9 was the highest at 482.14 U/mg. The optimal embedding conditions were sodium alginate 3.0% and calcium chloride 3.0%, and the activity of the enzyme was 480.71 U/g. When the free enzyme was placed at 4 ℃ for 5 days, the enzyme activity decreased to below 50%, and the enzyme activity of embedding enzyme remained above 90%. In the simulated gastrointestinal tract environment in vitro, the free enzyme completely lost its activity in simulated gastric juice within 10 min, while the retention rate of immobilized enzyme in gastric juice for 3 h and intestinal juice for 1 h was 56.39% and 56.35%, respectively. Conclusion: Sodium alginate-calcium chloride embedding method can significantly improve the ALDH stability of W. anomalus.

Keywords

• wickerhamomyces anomalus
• aldehyde dehydrogenase
• encapsulation
• stability