Simultaneous Saccharification and Fermentation of Lignocellulosic Biomass by Hybridized Yeast

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K00660
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Design and evaluation of sustainable and environmental conscious system
• Research Institution: Meisei University
• Principal Investigator: Tanaka Shuzo 明星大学, 理工学部, 教授 (00171760)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: バイオエタノール / アルカリ酸化処理 / MT酵素 / キシロース利用酵母FSC株 / 並行複発酵 / エタノール転換率 / リグノセルロース / 草木質バイオマス

Outline of Final Research Achievements

This study investigated the alkali-oxidative pretreatment, production and saccharification ability of the onsite MT-enzyme and simultaneous saccharification and fermentation (SSF) by xylose utilizing yeast FSC strain, aiming at ethanol production from lignocellulosic biomass (rice straw, oak and cedar).
By the alkali-oxidative pretreatment using NaOH and H2O2, carbohydrate saccharification rates obtained are 100% in rice straw, 73% in oak and 35% in cedar. The MT-enzyme could be efficiently produced using rice straw as a substrate and has possessed a high saccharification ability at 30 degree C. The freeze-preserved FSC strain could recover and maintain the fermentation ability originally possessed, after its cultivation for activation. The SSF of pretreated rice straw (BM) achieved 0.39 L/g-BM in ethanol production even at a high ratio of enzyme/substrate of 1/100, a low addition of enzyme, and satisfied the target of this study.

Free Research Field

草木質バイオマスからのバイオエタノール製造のための前処理、酵素糖化及び並行複発酵技術の研究・開発

Academic Significance and Societal Importance of the Research Achievements

草木質バイオマス（BM）からのエタノール製造は、BM構造の難糖化性、市販酵素の高価格及び酵母のキシロース利用不可の3点の課題を抱えている。本研究のアルカリ酸化処理、自前のMT酵素とFSC株による並行複発酵プロセスは、これらの課題を概ね解決し、その学術的・社会的な意義は大きい。特に、30℃高活性のMT酵素とキシロース利用FSC株による並行複発酵は独自の技術で、独創的である。達成したエタノール転換率は本プロセスの実用化を近づけ、仮にわが国の年間ガソリン消費量6,000万kLの10％にエタノールを使えば、単純計算で年間924万tの二酸化炭素排出を削減できることになる。