Purification and Enzymatic Properties of Inulinase from Kluyveromyces marxianus

Crude extracellular inulinase from Kluyveromyces marxianus was purified through sequential steps of ultrafiltration,DEAE-cellulose anion exchange chromatography and SephadexG-100 gel filtration to obtain two components,designated as Exo I and Exo II inulinase.The molecular weight of Exo I inulinase was 85 kD.The optimal reaction pH and temperature of Exo I were 4.0 and 60 ℃,respectively.In addition,Mn2+and Mg2+ could improve the activity of Exo I inulinase;in contrast,Cu2+ and Fe2+ exhibited a strong inhibition effect on Exo I inulinase activity.Enzymatic hydrolysates of inulin by Exo I inulinase were fructose and a small amount of glucose.