title: Bioconversion of xylose, hexoses and biomass to ethanol by a new isolate of the white rot basidiomycete Trametes versicolor.
abstract: Second-generation bioethanol production requires the development of economically feasible and sustainable processes that use renewable lignocellulosic biomass as a starting material. However, the microbial fermentation of xylose, which is the principal pentose sugar in hemicellulose, is a limiting factor in developing such processes. Here, a strain of the white rot basidiomycete Trametes versicolor that was capable of efficiently fermenting xylose was newly isolated and characterized. This strain, designated KT9427, was capable of assimilating and converting xylose to ethanol under anaerobic conditions with a yield of 0.44 g ethanol per 1 g of sugar consumed. In culture medium containing low yeast extract concentrations, xylose consumption and ethanol productivity were enhanced. Adjusting the initial pH between 3.0 and 5.0 did not markedly influence xylose fermentation. T. versicolor KT9427 also produced ethanol from glucose, mannose, fructose, cellobiose and maltose at yields ranging from 0.45 to 0.49 g ethanol per 1 g of sugar consumed. In addition, strain KT9427 exhibited favourable conversion of non-pretreated starch, cellulose, xylan, wheat bran and rice straw into ethanol compared to common recombinant yeast strains. Taken together, the present findings suggest that T. versicolor KT9427 is a promising candidate for environmentally friendly ethanol production directly from lignocellulosic biomass.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama, Tottori, 680-8552 Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Okamoto
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama, Tottori, 680-8552 Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Uchii
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama, Tottori, 680-8552 Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Kanawaku
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama, Tottori, 680-8552 Japan.
authors.forename: Hideshi
authors.initials: H
authors.lastname: Yanase
keywords: Biomass; Ethanol; Fermentation; White rot basidiomycete; Xylose