Elucidation of the molecular mechanism of nuclear increase in Aspergillus oryzae

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19062
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 38:Agricultural chemistry and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Takeshita Norio 筑波大学, 生命環境系, 准教授 (20745038)
• Co-Investigator(Kenkyū-buntansha): 織田 健 独立行政法人酒類総合研究所, 研究部門, 主任研究員 (10434466)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 麹菌 / 酵素生産 / 多核

Outline of Final Research Achievements

The nuclei of the yeast fungus Aspergillus oryzae were fluorescently labeled, and a phenomenon was discovered in which the number of nuclei in the cells increased over the course of culture. The increase in nuclei is expected to correlate with enzyme productivity, and may be a phenotype associated with the high enzyme productivity of Aspergillus oryzae. Live imaging analysis showed that hyphae with increased nuclei appear by branching, and that hyphae with more nuclei become dominant over time. Transcriptome analysis revealed a group of genes whose expression levels increase under the condition of increased nuclei. Phenotypes were analyzed in closely related species of practical strains for which genome information was available. Comparative genomic analysis of strains in the same clade showing different phenotypes was conducted, and candidate genes involved in nuclear gain were obtained.

Free Research Field

農芸化学

Academic Significance and Societal Importance of the Research Achievements

長い年月をかけて育種されてきた糸状菌A. oryzaeの特殊性を活かし、これまで知られていなかったA. oryzaeの高い酵素分泌能を特徴付ける新しい性質「核の増加の分子機構」を解明する研究である。糸状菌は、有用酵素・化合物生産の宿主に利用され、バイオ産業で重要な微生物である。本研究により分子機構が明らかになれば、糸状菌の種によらず、これまでにない有用糸状菌株の作製に繋がり、応用利用への影響が大きい。