Production and Characterization of Branched Oligosaccharides from Liquefied Starch by the Action of B. Licheniformis Amylase

A branched oligosaccharides (BOS) mixture was produced from liquefied starch solution using a maltogenic amylase of Bacillus licheniformis (BLMA). The BOS mixture was produced by both α‐1,4‐bond hydrolyzing and α‐1,6‐transglycosylation activities of BLMA, and it contained 58.3% of various branched oligosaccharides. Small branched oligosaccharides such as isomaltose, isopanose, and panose were identified in the mixture by various analyses including high performance ion‐chromatography (HPIC). Major branched DP4 and DP5 molecules in the mixture were determined as 6²‐O‐α‐maltosylmaltose, 6³‐O‐α‐maltosyl‐maltotriose and 6²‐O‐α‐maltotriosyl‐maltose, respectively. Time course study of BOS production suggested that the hydrolysis and transglycosylation reactions catalyzed by BLMA were coupled. BLMA was likely to transfer a sugar moiety hydrolyzed from a non‐reducing end of maltooligosaccharide, mainly maltose, to another moiety of sugar via the formation of α‐1,6‐linkage. Immobilization of BLMA was attempted as an effort to achieve a continuous process for BOS production. the immobilized enzyme showed improved thermal stability and slight loss of enzyme activity was observed during repeated usage.