Develop of a host microorganism that enables the direct fermentation of non-edible biomass

Research Project

Project/Area Number	16K18683
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Applied microbiology
Research Institution	National Institute of Advanced Industrial Science and Technology
Principal Investigator	Akita Hironaga 国立研究開発法人産業技術総合研究所, 機能化学研究部門, 研究員 (10738024)
Project Period (FY)	2016-04-01 – 2018-03-31
Project Status	Completed (Fiscal Year 2017)
Budget Amount *help	¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000) Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000) Fiscal Year 2016: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Keywords	バイオマス / リグニン分解 / Ureibacillus / 腸内細菌 / 貧栄養耐性 / 宿主微生物 / 腸内細菌科 / 新属新種細菌 / 木質系非可食バイオマス / リグニン / リグニン分解活性 / ゲノムシーケンス / バイオテクノロジー / 発酵 / ゲノム / プロテオーム
Outline of Final Research Achievements	To develop a novel gene expression system, we were planning to use lignin-degrading capability of Ureibacillus thermosphaericus. However, because U. thermosphaericus showed low the degrading capability, it was not suitable as a host bacterium. We therefore screened for lignin-degrading bacteria with a high capacity for lignin degradation. To obtain the bacteria, filtrates were prepared from several soil samples and then plated onto M9 plates (pH 7.2) containing alkali lignin as the sole carbon source. When the plate was incubated aerobically, individual colony was obtained from the leaf soil filtrate, and which named as strain CCA6. Although the degrading capability did not detected, strain CCA6 exhibited cell growth in oligotrophic condition. To identify the phylogeny strain CCA6, we performed the phylogenetic, phenotypic and biochemical characterization. As the result, strain CCA6 was considered to represent a novel species of a new genus in the family Enterobacteriaceae.
Academic Significance and Societal Importance of the Research Achievements	本研究で新たに単離したCCA6株は、貧栄養条件下でも良好な生育能を示す。また、栄養要求性が低く、廃糖蜜等の非可食バイオマスを利用して容易に増殖可能なことから、製造コストの大幅な削減につながる等、バイオものづくり用の宿主としての資質を有している。これまでに20種程度の貧栄養細菌が単離されており、それら細菌の貧栄養適応能が報告されているが、詳細なメカニズムは解明されていない。今後の研究により、貧栄養適応能メカニズムを分子レベルで解明できれば、知的財産の取得や学術論文の公表などを世界に先駆けて実施できる。