Purification and Characterization of Thermostable Pullulanase from Bacillus stearothermophilus and Molecular Cloning and Expression of the Gene in Bacillus subtilis.
A thermostable pullulanase (alpha-dextrin 6-glucanohydrolase [EC 3.2.1.41]) from a newly isolated Bacillus stearothermophilus strain (TRS128) was purified and characterized. The enzyme hydrolyzed (1-->6)-alpha-d-glucosidic linkages of pullulan to produce maltotriose, and the optimum temperature was 65 degrees C. About 90% of the enzyme activity was retained after treatment at 65 degrees C for 60 min. By using pTB522 as a vector plasmid, the pullulanase gene was cloned and expressed in Bacillus subtilis.
Kuriki
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Department of Fermentation Technology, Faculty of Engineering, Osaka University, Yamada-oka, Suita-shi, Osaka 565, and Biochemical Research Laboratories, Ezaki Glico Co., Ltd., Nishiyodogawa-ku, Osaka 555, Japan.
Park
J H
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Okada
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Imanaka
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