Giant dextran particles formed by dextransucrase immobilized on a tube surface in a laminar flow

Complexation of dextran with the active sites of dextransucrase was used to produce dextran on a tube in a laminar flow. A dextransucrase solution was passed through a Teflon tube at flow rates of 10 and 50 mL/h to immobilize the enzyme on the inner surface of the tube, and then sucrose solution was passed through the enzyme-immobilized tube to form giant dextran particles. The Reynolds number during the procedure was 4 or 20. The distribution of dextran along the flow direction in the tube was determined colorimetrically and showed that the dextran formed was distributed such that the amounts of dextran were higher near the ends than in the middle section of the tube. Direct observation of the dextran after colorization with phloxine showed that giant dextran particles, up to approximately 20 μm in size, were formed. The distribution of dextran produced by the enzymatic reaction in a laminar flow was determined quantitatively.

► Dextransucrase was immobilized on to the surface of the tube in a laminar flow.
► Sucrose substrate solution was flown to the dextransucrase-immobilized tube to produce dextran.
► The produced dextran was colorized and the distribution along the tube length was determined.