title: Direct and efficient ethanol production from high-yielding rice using a Saccharomyces cerevisiae strain that express amylases.
abstract: Efficient ethanol producing yeast Saccharomyces cerevisiae cannot produce ethanol from raw starch directly. Thus the conventional ethanol production required expensive and complex process. In this study, we developed a direct and efficient ethanol production process from high-yielding rice harvested in Japan by using amylase expressing yeast without any pretreatment or addition of enzymes or nutrients. Ethanol productivity from high-yielding brown rice (1.1g/L/h) was about 5-fold higher than that obtained from purified raw corn starch (0.2g/L/h) when nutrients were added. Using an inoculum volume equivalent to 10% of the fermentation volume without any nutrient supplementation resulted in ethanol productivity and yield reaching 1.2g/L/h and 101%, respectively, in a 24-h period. High-yielding rice was demonstrated to be a suitable feedstock for bioethanol production. In addition, our polyploid amylase-expressing yeast was sufficiently robust to produce ethanol efficiently from real biomass. This is first report of direct ethanol production on real biomass using an amylase-expressing yeast strain without any pretreatment or commercial enzyme addition.
authors: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
authors: Ryosuke
authors: R
authors: Yamada
authors: Syun-Ichi
authors: S
authors: Yamakawa
authors: Tsutomu
authors: T
authors: Tanaka
authors: Chiaki
authors: C
authors: Ogino
authors: Hideki
authors: H
authors: Fukuda
authors: Akihiko
authors: A
authors: Kondo
mesh_terms: D000681:Amylases / Q000378:metabolism*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D007564:Japan; D012275:Oryza / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D000516:alpha-Amylases / Q000378:metabolism
chemical_list: D003470:Culture Media; D000431:Ethanol; D000681:Amylases; D000516:alpha-Amylases