초록
<P>Ethanol production by the D-xylose fermentation of lignocellulosic biomass would augment environmental sustainability by increasing the yield of biofuel obtained per cultivated area. A set of recombinant strains derived from the industrial strain <I>Saccharomyces cerevisiae</I> CAT-1 was developed for this purpose. First, two recombinant strains were obtained by the chromosomal insertion of genes involved in the assimilation and transport of D-xylose (<I>Gal2</I>-N376F). Strain CAT-1-XRT was developed with heterologous genes for D-xylose metabolism from the oxo-reductive pathway of <I>Scheffersomyces stipitis</I> (<I>XYL1</I>-K270R, <I>XYL2</I>); and strain CAT-1-XIT, with D-xylose isomerase (<I>xylA</I> gene, XI) from <I>Streptomyces coelicolor.</I> Moreover, both recombinant strains contained extra copies of homologous genes for xylulose kinase (XK) and transaldolase (TAL1). Furthermore, plasmid (pRS42K::XI) was constructed with <I>xylA</I> from <I>Piromyces</I> sp. transferred to CAT-1, CAT-1-XRT, and CAT-1-XIT, followed by an evolution protocol. After 10 subcultures, CAT-1-XIT (pRS42K::XI) consumed 74% of D-xylose, producing 12.6 g/L ethanol (0.31 g ethanol/g D-xylose). The results of this study show that CAT-1-XIT (pRS42K::XI) is a promising recombinant strain for the efficient utilization of D-xylose to produce ethanol from lignocellulosic materials.</P>