1. Effect of pretreatment of hydrothermally processed rice straw with laccase-displaying yeast on ethanol fermentation.
- Author
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Nakanishi A, Bae JG, Fukai K, Tokumoto N, Kuroda K, Ogawa J, Nakatani M, Shimizu S, and Ueda M
- Subjects
- Cloning, Molecular, Fermentation, Laccase genetics, Molecular Sequence Data, Recombinant Proteins genetics, Recombinant Proteins metabolism, Saccharomyces cerevisiae enzymology, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Sequence Analysis, DNA, Trametes genetics, Ethanol metabolism, Laccase metabolism, Oryza metabolism, Oryza microbiology, Trametes enzymology
- 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.
- Published
- 2012
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