Development of new inactivation method for waterborne virus using heat-denatured lysozyme

• Project/Area Number: 17H03872
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Aquatic life science
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: Takahashi Hajime 東京海洋大学, 学術研究院, 准教授 (40413116)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥18,330,000 (Direct Cost: ¥14,100,000、Indirect Cost: ¥4,230,000); Fiscal Year 2019: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2018: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2017: ¥11,960,000 (Direct Cost: ¥9,200,000、Indirect Cost: ¥2,760,000)
• Keywords: ノロウイルス / リゾチーム / 不活化法 / 加熱変性リゾチーム / 不活化 / 食品微生物 / 肝炎ウイルス

Outline of Final Research Achievements

In a previous study, we found that heat-denatured lysozyme (DL) had an anti-norovirus effect. Lysozyme is a lytic enzyme that acts on bacteria. We believe that heat denaturation of lysozyme causes it to act as a peptide, which inactivates the virus. In this study, we investigated the inactivation mechanism of norovirus by DL and its applicability. We found that the pH during heat denaturation was related to the virus inactivating ability, and also found that the effect was changed by substituting any amino acid. Moreover, although the phenomenon of aggregation in salt solution hindered the applicability of DL, the solubility was improved by using cyclodextrin.

Academic Significance and Societal Importance of the Research Achievements

本研究ではペプチドとして働くリゾチームの性質に着目し、リゾチームの加熱条件とノロウイルスに対する不活化効果の関係、不活化効果が高くなる変性条件、また、製剤化を目指し加熱変性リゾチームの溶解性の向上など様々な項目について研究を行ってきた。
結果、様々な水系感染症ウイルスへその用途を示すことができ、食品製造の現場で使用可能な新たなウイルス不活化剤の開発へとつなげることができた。さらに、養殖や畜養、食品原料の洗浄など新たな応用法となりうることも示した。また、活性部位を同定し、効果増強が可能な方法を見出したことにより、安定的にペプチド製剤として生産できる可能性も示すことができた。

Research Products

• [Int'l Joint Research] Program in Biotechnology/Faculty of Science/Chulalongkorn University(タイ)
• [Int'l Joint Research] Research and Development/Betagro Group(タイ)
• [Journal Article] Inactivating effect of heat-denatured lysozyme on murine norovirus in bread fillings (2018)
  • Author(s): Michiko Takahashi, Yuka Yasuda, Hajime Takahashi, Akira Takeuchi, Takashi Kuda, Bon Kimura
  • Journal Title: Food Hygiene and Safety Volume: 59 Pages: 89-92
  • NAID: 130006725767
  • Peer Reviewed
• [Journal Article] Heat-denatured lysozyme could be a novel disinfectant for reducing hepatitis A virus and murine norovirus on berry fruit (2018)
  • Author(s): Takahashi Michiko、Okakura Yumiko、Takahashi Hajime、Imamura Minami、Takeuchi Akira、Shidara Hiroyuki、Kuda Takashi、Kimura Bon
  • Journal Title: International Journal of Food Microbiology Volume: 266 Pages: 104-108
  • DOI: 10.1016/j.ijfoodmicro.2017.11.017
  • Peer Reviewed
• [Presentation] 加熱変性リゾチームのノロウイルス不活化機構に関する基礎的研究 (2018)
  • Author(s): 高橋迪子、中條弥生、岡倉優美子、市川将弘、仲沢萌美、高橋肇、久田孝、木村凡
  • Organizer: 第114回日本食品衛生学会学術講演会
• [Presentation] Inactivation of human norovirus using heat-denatured lysozyme (2017)
  • Author(s): Satomi Kanagawa, Hajime Takahashi, Chihiro Ohshima, Michiko Takahashi, Kiyofumi Ohkusu, Moemi Nakazawa, Akira Takeuchi, Hiroyuki Shidara, Masaaki Kunou, Takashi Kuda, Bon Kimura
  • Organizer: European Federation of Food Science and Technology 31st International Conference
  • Int'l Joint Research