Aromatic compounds productino from lignocellulosic biomass by engineered lactic acid bacteria

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K18299
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Biofunction/Bioprocess
• Research Institution: Osaka University
• Principal Investigator: Okano Kenji 大阪大学, 工学研究科, 助教 (40623335)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 乳酸菌 / Lactobacillus plantarum / エタノール / 芳香族化合物 / リグノセルロース / ホスホケトラーゼ経路 / ペントースリン酸経路

Outline of Final Research Achievements

Construction of an engineered Lactobacillus plantarum strain, which produces no lactate and enables simultaneous utilization of C5 and C6 sugars, was performed. Deletion of lactate dehydrogenase gene allowed inhibition of lactate production. However, disruption of redox balance in the resultant strain led decrease of transformation efficiency and further gene modification was impossible. Therefore, lactate dehydrogenase gene was replaced with pyruvate decarboxylase and alcohol dehydrogenase. This resulting strain allows further gene modification and its C5 sugar utilization was partially improved. Unfortunately, aromatic compound production was not performed due to this transformation barrier. However, this study gave us important findings for gene modification of non-lactate producing strain.

Free Research Field

生物化学工学

Academic Significance and Societal Importance of the Research Achievements

脱石油化・低炭素化社会の実現に向け、再生可能資源であるバイオマス資源から生産可能なバイオプラスチックの需要が拡大している。既存市場は脂肪族ポリマーが中心であったが、力学的物性・耐熱性のより高い芳香族ポリマーの生産技術の開発が活発化している。本研究は非可食資源で賦存量の多いリグノセルロース系バイオマスからの芳香族ポリマー原料の生産技術を提供するもので社会的意義は大きい。残念ながら研究期間内には芳香族化合物生産には至らなかったものの、乳酸生産能の欠損が乳酸菌の代謝生理に及ぼす様々な影響が明らかになるとともに、遺伝子改変のための基本的戦略が確立され、その学術的意義は大きい。