Insecticidal factors produced by Bacillus subtilis

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05649
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Ehime University
• Principal Investigator: NISHIWAKI HISASHI 愛媛大学, 農学研究科, 教授 (30508784)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 枯草菌 / 殺虫活性 / 微生物農薬

Outline of Final Research Achievements

The insecticidal factors were isolated from the culture broth of the insecticidal Bacillus subtilis. SDS-PAGE analyses demonstrated that the insecticidal fractions included not only proteins (ca. 60 kDa) but also a peptide (3.4 kDa) showing the insecticidal activity against the larvae of mosquitoes Culex pipiens and the adults of houseflies Musca domestica, respectively. MALDI TOF MS analyses suggested that some enzymes including reductase should be the candidates as the insecticidal proteins against the mosquito larvae. On the other hand, the N terminus of the peptide with the molecular weight of 3.4 kDa was not able to be analyzed using the protein sequencer, suggesting that the peptide should be blocked at the N-terminus or cyclic.

Free Research Field

農薬科学

Academic Significance and Societal Importance of the Research Achievements

本研究により，殺虫性枯草菌がタンパク質性ならびにペプチド性の殺虫成分を生産することを明らかにすることができた。このうち，ペプチド性殺虫成分に関して，ラット赤血球に対する溶血活性が認められなかったことは，哺乳類に対して安全性が高いことを強く示唆する。また，このペプチドは熱には安定であったことから，将来商品化する際に加工しやすい可能性がある。
安全性の高い微生物農薬を提案できる可能性のある本研究の成果は，化学農薬による環境負荷を減らすことが期待でき，総合的病害虫管理(IPM)推進の手助けになると考えられる。