Technical note: Application of immobilized cells of Kluyveromyces marxianus for continuous hydrolysis to fructose of fructans in Jerusalem artichoke extracts

Abstract

Dead cells of Kluyveromyces marxianus having inulase (β‐D‐fructo fructanohydrolase E.C.3.2.1.7) activity were immobilized in alginate beads and used as a biocatalyst in a packed bed reactor and a stirred batch reactor. Fructosans of Jerusalem artichoke tubers, after extraction, were utilized for continuous or semi‐continuous production of fructose. In a bed reactor packed with 100 ml of beads, a volumetric productivity of 36 g/l/hr total reducing sugars was obtained with 98% substrate conversion. When operated continuously for 30 days, a half life of 28 days was observed for the biocatalyst. Using artichoke extract containing 20% fructan solution, 98% conversion could be achieved in a batch reactor in 20 hr. Repeated cycling of beads resulted in considerable loss of catalyst from the reactor and subsequent loss in catalytic activity, thus giving a half life of only 14 days.