A METHOD OF PREPARING PULLULAN HAVING VARIOUS MOLECULAR WEIGHT

摘要

PURPOSE: A method for preparing pullulan of various molecular weights is provided to develop technique for manufacturing pullulan of large molecular weight and to reduce manufacturing cost. CONSTITUTION: A method for preparing pullulan of various molecular weights comprises a step of adding a sample having pH concentration buffering ability to a second medium containing K_2HPO_4 NaCl, MgSO_47H_2O, (NH_4)_2SO_4, yeast extract, and sugar or a step of changing pH concentration. In case of desiring 200-300kDa of molecular weight ascorbic acid is added to the second medium and culturing Aureobasicium pullulans by changing pH concentration from pH 5.8-6.2 to 4.8-5.2 within 24 hours. Pullulan is isolated and purified using an inorganic membrane filter system. The filter system is formed of ceramic or stainless filter membrane.