title: Effect of pretreatment of hydrothermally processed rice straw with laccase-displaying yeast on ethanol fermentation.
abstract: A gene encoding laccase I was identified and cloned from the white-rot fungus Trametes sp. Ha1. Laccase I contained 10 introns and an original secretion signal sequence. After laccase I without introns was prepared by overlapping polymerase chain reaction, it was inserted into expression vector pULD1 for yeast cell surface display. The oxidation activity of a laccase-I-displaying yeast as a whole-cell biocatalyst was examined with 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), and the constructed yeast showed a high oxidation activity. After the pretreatment of hydrothermally processed rice straw (HPRS) with laccase-I-displaying yeast with ABTS, fermentation was conducted with yeast codisplaying endoglucanase, cellobiohydrolase, and β-glucosidase with HPRS. Fermentation of HPRS treated with laccase-I-displaying yeast was performed with 1.21-fold higher activities than those of HPRS treated with control yeast. The results indicated that pretreatment with laccase-I-displaying yeast with ABTS was effective for direct fermentation of cellulosic materials by yeast codisplaying endoglucanase, cellobiohydrolase, and β-glucosidase.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Nakanishi
authors.forename: Jun Gu
authors.initials: JG
authors.lastname: Bae
authors.forename: Kotaro
authors.initials: K
authors.lastname: Fukai
authors.forename: Naoki
authors.initials: N
authors.lastname: Tokumoto
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kuroda
authors.forename: Jun
authors.initials: J
authors.lastname: Ogawa
authors.forename: Masato
authors.initials: M
authors.lastname: Nakatani
authors.forename: Sakayu
authors.initials: S
authors.lastname: Shimizu
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ueda
mesh_terms: D003001:Cloning, Molecular; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D042845:Laccase / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D012275:Oryza / Q000378:metabolism* / Q000382:microbiology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D055454:Trametes / Q000201:enzymology* / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D000431:Ethanol; D042845:Laccase