초록
<P>In this study, the <I>xyn2</I> gene, which encodes an endo-β-1,4-xylanase, was isolated with holocellulose extracted from Juncao <I>Miscanthus floridulu </I>as an inducer. The <I>xyn2</I> gene expressed in <I>Escherichia coli</I>, with the estimated yield of 349 U·mL<SUP>-1</SUP>. Zymogram analysis showed that the purified Xyn2 had only one band on SDS-PAGE with an estimated molecular mass of 28 kDa. Enzymology analysis demonstrated that its optimum activity was at pH 6.0 and 60°C, with stability at pH range 4.0~7.0 and temperature up to 50°C. The metal ions Cu<SUP>2+</SUP> and Mg<SUP>2+</SUP> showed some inhibition effects, while Fe<SUP>2+</SUP> and Fe<SUP>3+</SUP> had small stimulating effects. Its values of <I>Km</I> and <I>Vmax </I>are 2.85 mM and 50.2 mM/min, respectively. Based on our results, we propose a novel way to convert Juncao biomass into energy and other useful products.</P>