Abstract
Bacillus stearothermophilus K-12481, which was isolated from soil, produced an intracellular cyclodextrinase. The strain seemed to produce at least three components of cyclodextrinase and one of them was purified to homogeneity. The enzyme was a dimer and the molecular weight of a subunit was 67, 000 and it showed the highest activity at 60°C and pH 6 .5. The enzyme degraded α-cyclodextrin (α-CD) two times faster than β-CD and γ-CD and had low activity toward high-molecular-weight substrates such as glycogen and amylopectin. The enzyme also had high activity toward malto oligosaccharides of DP 4-7. α-CD was the best substrate among those tested . All CDs were hydrolyzedinto glucose and maltose.
