Regulation of CAZyme genes expression in a cellulolytic Clostridium bacterium

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K18218
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 64030:Environmental materials and recycle technology-related
• Research Institution: Mie University
• Principal Investigator: Ichikawa Shunsuke 三重大学, 教育学部, 講師 (50781118)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: セルロース系バイオマス / セルロース分解細菌 / 糖質関連酵素

Outline of Final Research Achievements

The cellulytic bacterium Clostridium thermocellum recognizes the structure and constituents of cellulosic biomass and secretes multiple degradative enzymes suitable for its degradation via gene expression regulators (σ-factors). Transcriptome analysis revealed that the expression of 47 carbohydrate-active enzyme genes were promoted and eight were repressed in C. thermocellum sigI7 expression strain. The cellulosic biomass degradation activity of the cultures of the sigI7 strain was lower than that of the wild-type stain. Xylanases with molecular weight of approximately 75 kDa and 50 kDa were reduced in the culture of the sigI7 strain.

Free Research Field

応用微生物学、生化学

Academic Significance and Societal Importance of the Research Achievements

未利用資源であるセルロース系バイオマスからの原油代替化合物生産（バイオリファイナリー）を実現するために、セルロース系バイオマスの効率的分解を達成する必要がある。バイオリファイナリーの候補微生物であるClostridium thermocellumはセルロース系バイオマスの構造や構成成分を認識し、遺伝子発現調節因子（σ因子）を介して、その分解に適した多種の分解酵素を分泌する。本研究では、σ因子の機能を明らかにすることでC. thermocellumのバイオマス分解酵素生産の調節メカニズムの一端を明らかにした。