Production of Maltohexaose by α-Amylase from Bacillus circulans G-6 |
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Authors: | Yoshiyuki Takasaki |
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Institution: | Fermentation Research Institute, Agency of Industrial Science and Technology, Ministry of International Trade and Industry, 1-1-3, Azuma, Yatabe-machi, Tsukuba-gun, Ibaraki 305, Japan |
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Abstract: | An α-amylase which produces maltohexaose as the main product from strach was found in the culture filtrate of Bacillus circulans G-6 which was isolated from soil and identified by the author.The enzyme was purified by means of ammonium sulfate fractionation, DEAE-Sepharose column chromatography and Sephadex G-200 column chromatography. The purified enzyme was homogeneous on disc electrophoresis. The optimum pH and temperature of the enzyme were around pH 8.0 and around 60°C, respectively. The enzyme was stable in the range of pH 5–10. Metal ions such as Hg2+, Cu2+, Zn2+, Fe2+ and Co2+ inhibited the enzyme activity. The molecular weight was about 76,000. The yield of maltohexaose from soluble starch of DE (dextrose equivalent*) 1.8-12.6 was about 30%, and the combined action of the enzyme and pullulanase or isoamylase increased the yield of maltohexaose. |
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