1. Effect of pretreatment of hydrothermally processed rice straw with laccase-displaying yeast on ethanol fermentation.
- Author
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Nakanishi, Akihito, Bae, Jun, Fukai, Kotaro, Tokumoto, Naoki, Kuroda, Kouichi, Ogawa, Jun, Nakatani, Masato, Shimizu, Sakayu, and Ueda, Mitsuyoshi
- Subjects
POLYMERASE chain reaction ,LACCASE ,YEAST ,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. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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