Production of Maltosyl β‐Cyclodextrin by a Bioreactor System with Pullulanase Immobilized on Partially Deacetylated Chitin

Thermostable pullulanase (EC 3.2.1.41) from Bacillus acidopullulyticus was well immobilized on partially deacetylated chitin (PDAC‐35) with glutaraldehyde. The immobilized enzyme showed the ability of producing maltosyl β‐cyclodextrin (6‐α‐maltosylcyclomaltoheptaose) through a reverse action in a reaction mixture containing high concentration of maltose and β‐cyclodextrin, and a bioreactor system with the immobilized enzyme could produce the branched cyclodextrin more efficiently than the native enzyme. The reaction mixture was passed through a charcoal column to remove large amounts of maltose, and cyclodextrins adsorbed in the column were eluted with ethanol solutions. β‐Cyclodextrin, maltosyl β‐Cyclodextrin, and dimaltosyl β‐cyclodextrin were separated by using a ODS or a GPC column.