Abstract
A bacterium which produces a pullulanase was isolated from soil. A pullulanase (BSP) produced by the strain, Bacillus sectorramus, was purified by precipitation with ammonium sulfate and chromatographies on Phenyl-Sepharose CL-4B, DEAE-Sepharose CL-6B, γ-Cyclodextrin-Sepharose, and Toyopearl HW-55S. The purified enzyme was homogeneous in slab electrophoresis. The optimum pH and temperature of BSP were about 5.0 and 55°C, respectively. The molecular weight of BSP was estimated as 96, 000 and its isoelectric point was 4.7. The action pattern of this enzyme on pullulan was endo-wise. The final product from pullulan was maltotriose, not trimer which has a-l, 6 linkage in the molecular. By adding BSP, it was possible to significantly increase the glucose level in the standard condition of saccharification (pH 4.5, 60°C).
