title: Direct ethanol production from starch using a natural isolate, Scheffersomyces shehatae: Toward consolidated bioprocessing.
abstract: Consolidated bioprocessing (CBP), which integrates enzyme production, saccharification and fermentation into a one-step process, is a promising strategy for cost-effective ethanol production from starchy biomass. To gain insights into starch-based ethanol production using CBP, an extensive screening was undertaken to identify naturally occurring yeasts that produce ethanol without the addition of any amylases. Three yeast strains were capable of producing a significant amount of ethanol. Quantitative assays revealed that Scheffersomyces shehatae JCM 18690 was the strain showing the highest ethanol production ability. This strain was able to utilize starch directly, and the ethanol concentration reached 9.21 g/L. We attribute the ethanol-producing ability of this strain to the high levels of glucoamylase activity, fermentation potential and ethanol stress tolerance. This study strongly suggests the possibility of starch-based ethanol production by consolidated bioprocessing using natural yeasts such as S. shehatae JCM 18690.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Tanimura
authors.affiliation: Research Division of Microbial Sciences, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Kikukawa
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Shino
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Kishino
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Ogawa
authors.affiliation: Faculty of Law, Ryukoku University, 67 Fukakusatsukamoto-cho, Fushimi-ku, Kyoto 612-5662, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Shima
mesh_terms: D018533:Biomass; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005087:Glucan 1,4-alpha-Glucosidase / Q000378:metabolism; D004718:Saccharomycetales / Q000201:enzymology / Q000378:metabolism*; D013213:Starch / Q000378:metabolism; D000516:alpha-Amylases / Q000378:metabolism
chemical_list: D000431:Ethanol; D013213:Starch; D000516:alpha-Amylases; D005087:Glucan 1,4-alpha-Glucosidase