초록
<P><I>T. reesei</I> is an efficient cellulase producer and biomass degrader. To improve xylitol production in <I>Trichoderma reesei</I> strains by genetic engineering, two approaches were used in this study. First, the presumptive D-xylulokinase gene in <I> T. reesei</I> (<I>xyiH</I>), which has high homology to known fungi D-xylulokinase genes, was silenced by transformation of <I> T. reesei</I> QM9414 strain with an antisense construct to create strain S6-2-2. The expression of the <I> xyiH</I> gene in the transformed strain S6-2-2 decreased at the mRNA level, and D-xylulokinase activity decreased after 48 h of incubation. This led to an increase in xylitol production from undetectable levels in wild-type <I> T. reesei</I> QM9414 to 8.6 mM in S6-2-2. The <I> T. reesei</I> Δxdh is a xylose dehydrogenase knockout strain with increased xylitol production compared to the wild-type <I> T. reesei</I> QM9414 (22.8 mM versus undetectable). The copy number of the xylose reductase gene (<I>xyl</I>1) in <I> T. reesei </I> Δxdh strain was increased by genetic engineering to create a new strain Δ9-5-1. The Δ9-5-1 strain showed a higher <I> xyl</I>1 expression and a higher yield of xylose reductase, and xylitol production was increased from 22.8 mM to 24.8 mM. Two novel strains S6-2-2 and Δ9-5-1 are capable of producing higher yields of xylitol. <I> T. reesei</I> has great potential in the industrial production of xylitol.</P>