泡盛麹菌の生産するα-アミラ-ゼおよびグルコアミラ-ゼの酵素化学的性質  [in Japanese] Properties of α-amylase and glucoamylase from Aspergillus awamori (Department of Bioscience and Biotechnology)  [in Japanese]

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Abstract

酵素活性及び生酸性のバランスがとれた泡盛麹菌(Aspergillus awamori, Nakazawa IFO 4033)の生産するα-アミラーゼ及びグルコアミラーゼの酵素化学的諸性質を検討し,以下の結果を得た。(1)供試菌株の生産するα-アミラーゼの反応最適pHは4.5∿5.5,pH安定性は3.0∿6.0の範囲で安定であった。本酵素の反応最適温度は65℃,温度安定性は60℃まで安定であった。(2)供試菌株の生産するグルコアミラーゼの最適pHは5付近(4.3∿5.3)で,pH安定性は3.5∿6.0の範囲で安定であった。本酵素の反応最適温度は60℃,温度安定性は60℃まで安定であった。(3)供試菌株グルコアミラーゼの米(タイ国産砕米,うるち,もち),馬鈴薯,甘藷,小麦,とうもろこしの糊化デンプンに対する反応性を調べたところ,いずれも可溶性デンプンとほぼ同様の値を示した。(4)供試菌株グルコアミラーゼのタイ国産砕米デンプンに対する加水分解率は反応時間の経過に伴い増大し,反応24時間における値は82%であった。(5)供試菌株の生デンプン(タイ国産砕米)の分解活性の反応最適pHは3.2∿3.5であった。(6)供試菌株の各種生デンプン分解活性はウルチ米,タイ国産砕米及びもち米などで高い値を示し,小麦やとうもろこしにも比較的高い値を示した。しかし,生馬鈴薯デンプンに対する分解活性は著しく低い値を示した。Awamori koji prepared by growing Aspergillus awamori on steamed rice is a very important material for the production of awamori beverage which is a traditional distilled liquor in Okinawa Prefecture, Japan. In awamori beverage production, the strain which has high amylolytic enzyme activities and acid productivity is needed. And thus, screening of Aspergillus awamori for the object was carried out as reported in the previous paper. In this paper, properties of α-amylase and glucoamylase from selected strain (Aspergillus awamori) were investigated. α-Amylase had the maximum reactivity at pH 4.5-5.5 and 65℃. The enzyme was quite stable in a range of pH 3.0-6.0,and stable up to 65℃. Glucoamylase had the maximum reactivity at pH 4.3-5.5 and 60℃. The enzyme was stable in a range of pH 3.5-6.0 and stable up to 60℃. Glucoamyase was active on the gelatinized starch prepared from glutinous rice, nonglutinous rice, broken rice imported from Thailand (raw material for awamori beverge, indica type), potato, sweet potato, wheat and corn as well as soluble starch. The hydrolysis degree of starch prepared from broken rice of Thailand was rapidly increased with increasing time up to 2 hr. The limit of hydrolysis of the starch by this enzyme was 82%. It was found that the enzyme could digest raw rice starch maximally at pH 3.2-3.5. The enzyme was very active on raw rice starch such as glutinous, nonglutinous and broken rices but was only a little active on raw potato starch.

Awamori koji prepared by growing Aspergillus awamori on steamed rice is a very important material for the production of awamori beverage which is a traditional distilled liquor in Okinawa Prefecture, Japan. In awamori beverage production, the strain which has high amylolytic enzyme activities and acid productivity is needed. And thus, screening of Aspergillus awamori for the object was carried out as reported in the previous paper. In this paper, properties of α-amylase and glucoamylase from selected strain (Aspergillus awamori) were investigated. α-Amylase had the maximum reactivity at pH 4.5-5.5 and 65℃. The enzyme was quite stable in a range of pH 3.0-6.0,and stable up to 65℃. Glucoamylase had the maximum reactivity at pH 4.3-5.5 and 60℃. The enzyme was stable in a range of pH 3.5-6.0 and stable up to 60℃. Glucoamyase was active on the gelatinized starch prepared from glutinous rice, nonglutinous rice, broken rice imported from Thailand (raw material for awamori beverge, indica type), potato, sweet potato, wheat and corn as well as soluble starch. The hydrolysis degree of starch prepared from broken rice of Thailand was rapidly increased with increasing time up to 2 hr. The limit of hydrolysis of the starch by this enzyme was 82%. It was found that the enzyme could digest raw rice starch maximally at pH 3.2-3.5. The enzyme was very active on raw rice starch such as glutinous, nonglutinous and broken rices but was only a little active on raw potato starch.

Journal

  • The Science bulletin of the College of Agriculture,Universty of the Ryukyus

    The Science bulletin of the College of Agriculture,Universty of the Ryukyus (39), p125-134, 1992-12

    University of the Ryukyus

Codes

  • NII Article ID (NAID)
    110000219809
  • NII NACSIS-CAT ID (NCID)
    AN00250548
  • Text Lang
    JPN
  • Article Type
    Departmental Bulletin Paper
  • Journal Type
    大学紀要
  • ISSN
    03704246
  • NDL Article ID
    3810883
  • NDL Source Classification
    PA63(醗酵・微生物工学--酒類・アルコール)
  • NDL Source Classification
    ZR7(科学技術--農林水産--農産)
  • NDL Call No.
    Z18-881
  • Data Source
    NDL  NII-ELS  IR 
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