초록
<P>Xylose is the second most abundant sugar in lignocellulosic materials and can be converted to ethanol by recombinant <I>Saccharomyces cerevisiae</I> yeast strains expressing heterologous genes involved in xylose assimilation pathways. Recent research demonstrated that disruption of the alkaline phosphatase gene, <I>PHO13</I>, enhances ethanol production from xylose by a strain expressing the xylose reductase (XR) and xylitol dehydrogenase (XDH) genes; however, the yield of ethanol is poor. In this study, <I>PHO13</I> was disrupted in a recombinant strain harboring multiple copies of the xylose isomerase (XI) gene derived from <I>Orpinomyces</I> sp., coupled with overexpression of the endogenous xylulokinase (XK) gene and disruption of <I>GRE3</I>, which encodes aldose reductase. The resulting YΔGP/XK/XI strain consumed 2.08 g/L/h of xylose and produced 0.88 g/L/h of volumetric ethanol, for an 86.8 % theoretical ethanol yield, and only YΔGP/XK/XI demonstrated increase in cell concentration. Transcriptome analysis indicated that expression of genes involved in the pentose phosphate pathway (<I>GND1</I>, <I>SOL3</I>, <I>TAL1</I>, <I>RKI1</I>, and <I>TKL1</I>) and TCA cycle and respiratory chain (<I>NDE1</I>, <I>ACO1</I>, <I>ACO2</I>, <I>SDH2</I>, <I>IDH1</I>, <I>IDH2</I>, <I>ATP7</I>, <I>ATP19</I>, <I>SDH4</I>, <I>SDH3</I>, <I>CMC2</I>, and <I>ATP15</I>) was upregulated in the YΔGP/XK/XI strain. And the expression levels of 125 cell cycle genes were changed by deletion of <I>PHO13</I>.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s13568-015-0175-7) contains supplementary material, which is available to authorized users.</P>