Tannic Acid Enhancing Insecticidal Activity of Protoxin Produced in Bacillus thuringiensis subsp. Kurstaki KB100 Strain Against Spodoptera exigua

DOI HANDLE Open Access
  • Jin Na Young
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University
  • Lee You Kyoung
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University
  • Lee Bo Ram
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University
  • Kim Yu Seop
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University
  • Jun Jun Hack
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University
  • Seo Mi Ja
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University
  • Youn Young Nam
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University
  • Aoki Chisa
    Laboratory of Insect Pathology and Microbial Control, Institute of Biological Control, Faculty of Agriculture, Kyushu University : Associate Professor
  • Yasunaga Chisa
  • Yu Yong Man
    Department of Applied Biology, College of Agriculture and Life Sciences, chungnam National University

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Abstract

Insecticidal activity was enhanced when Bacillus thuringiensis subsp. kurstaki KB100 strain containing insecticidal activity against Spodoptera exigua was mixed with tannic acid, a protease inhibitor. To investigate the cause of this result, inhibition rate of tannic acid against protease activity in midgut juice of S. exigua was measured. As a result, it was found that protease activity in midgut juice of S. exigua was about 83.1%, 77.6%, 68.0%, and 40.1% at concentrations of 10, 20, 40 and 80 mM, respectively. Such reduction of protease activity was measured with increasing concentration. Analysis of substrate reaction in several kinds of proteases was performed. Trypsin exhibited 91.4% and 89.4% of proteolytic activity in BApNA and BPVApNA substrates, respectively. Thus, when Trypsin was treated with tannic acid, proteolytic activity was 62.2% and 54.5% in BApNA and BPVApNA substrates, respectively. Trypsin's proteolytic activity was inhibited by 29.2% and 34.9% when mixed with tannic acid. However, proteolytic activity of chymotrypsin and elastase was not inhibited by tannic acid. Digestion of protoxin produced in B. thuringiensis KB100 strain by Trypsin was analyzed using SDS–PAGE. As a result, a band appeared at about 60 kDa–70 kDa and it seemed to be inhibited by tannic acid. Digestion patterns of protoxin were measured over time. As it was over–digested in a group of Trypsin treatment, a band of protoxin at 60 kDa completely disappeared. On the other hand, when it was treated with tannic acid, a digestion inhibitor, protoxin was maintained for up to 24 hours.

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Details 詳細情報について

  • CRID
    1390009224684828160
  • NII Article ID
    120005661329
  • NII Book ID
    AA00247166
  • DOI
    10.5109/1526296
  • HANDLE
    2324/1526296
  • ISSN
    00236152
  • Text Lang
    en
  • Data Source
    • JaLC
    • IRDB
    • Crossref
    • CiNii Articles

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