Abstract:
Fructosyltransferase was a key catalyst for the enzymatic production of fructooligosaccharides. The immobilized enzyme had the advantages of stable catalytic properties, repeated use and saving the enzyme cost. The study on the catalytic properties of immobilized fructosyltransferase could provide data basis for its industrial application. The fructosyltransferase was immobilized by using the embedding method with sodium alginate as the carrier. Then, the catalytic characteristics such as the optimum catalytic temperature, thermal stability, optimum reaction pH, pH stability and enzymatic kinetics were investigated. The application of immobilized fructosyltransferase in the catalytic synthesis of fructooligosaccharides was also preliminarily studied. The results showed that the optimum catalytic temperature of fructosyltransferase immobilized by the sodium alginate embedding method was 50℃, the pH value was 5.0, and the michaelis-menten constant (
Km) of enzymatic kinetics was 0.03 mg·mL
-1. 48.03% purity of fructooligosaccharides could be prepared by using the immobilized enzyme and sucrose as the substrate. Compared with the soluble enzyme, the sodium alginate immobilized fructosyltransferase had better compatibility with sucrose substrate, better temperature and pH stability, and had better potential for the industrial application.