2013 Fiscal Year Final Research Report

Development of highly efficient bioethanol production yeast by genetic engineering

Research Project

Project/Area Number	23603003
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Biomass energy
Research Institution	Kyoto University
Principal Investigator	KODAKI TSUTOMU 京都大学, エネルギー理工学研究所, 准教授 (70170264)
Project Period (FY)	2011 – 2013
Keywords	バイオエタノール / 酵母 / キシロース / タンパク質工学
Research Abstract	Since xylose is one of the major fermentable sugars present in lignocellulosic biomass, the efficient fermentation of xylose is required to develop economically viable processes for producing bioethanol. In this study, construction of the strictly NADPH dependent xylose reductase from Pichia stipitis was succeeded by site directed mutagenesis. The more efficient xylose fermentation and the decrease of xylitol excretion was observed by introducing the strictly NADPH dependent XR with the strictly NADP+ dependent XDH. Next, by introducing many putative genes of xylose transporters of P. stipitis, the XUT1 and SUT1 genes of Pichia stipitis were shown to be the most effective on xylose consumption. Furthermore, Overexpression of the enzymes involved in the pentose phosphate pathway was shown to have positive effects on xylose fermentation.