초록
<P><B>Abstract</B></P> <P>Bacterial inulinases are the key enzymes in the enzymatic hydrolysis of inulin and production of fructooligosaccharides (FOSs) and high fructose syrup (HFS). An extremophilic inulinase was purified from <I>Alkalibacillus filiformis</I> using 80% ethanol precipitation, ultrafiltration, and Q-Sepharose anion exchange chromatography. The purified inulinase was highly active in a wide range of pH, temperature, chemical reagents, and NaCl concentrations. The enzyme immobilization on cobalt ferrite magnetic nanoparticles (CoFe<SUB>2</SUB>O<SUB>4</SUB> MNPs) was carried out by carrier binding method with covalent linkage and showed improved stability and reusability within a broad temperature and pH range, compared with the free enzyme. Using free and immobilized inulinases from <I>A. filiformis</I>, 122 g L<SUP>−1</SUP> and 160 g L<SUP>−1</SUP> fructose with 61% and 80% conversion, respectively, were obtained, with inulin as the substrate. The enzymatic properties, such as notable stability under extreme conditions, make the inulinase from <I>A. filiformis</I> a promising candidate for related biotechnological applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An extremophile inulinase was isolated from the bacterium <I>Alkalibacillus filiformis.</I> </LI> <LI> The enzyme was stable against some salt, solvents, chemicals, and pH-temperature ranges. </LI> <LI> The inulinase immobilization was conducted by covalent attachment on CoFe<SUB>2</SUB>O<SUB>4</SUB> MNPs. </LI> <LI> The immobilized inulinase was used for production of high fructose syrup. </LI> <LI> 122 g L<SUP>−1</SUP> and 160 g L<SUP>−1</SUP> fructose were obtained by the free and immobilized enzyme during 48 h. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>