초록
<P>Ethanologenic white-rot fungus <I>Phlebia</I> sp. MG-60-P2 produces ethanol directly from several lignocelluloses. Efficient gene silencing methods are needed for metabolic engineering of this fungus for biorefinery use. In this study, we evaluated the effectiveness of RNAi-mediated silencing of the pyruvate decarboxylase gene of <I>Phlebia</I> sp. MG-60-P2 (MG<I>pdc1</I>). The RNAi lines generated showed a variety of suppression levels of ethanol production and MG<I>pdc1</I> expression, and two selected strains led to different metabolic fluxes, resulting in rapid accumulation of xylitol from xylose. Knockdown lines KD2 and KD10 showed different strength of silencing. The moderate-inhibition line (KD10) showed faster xylitol accumulation from xylose than the severe-inhibition line (KD2). KD2, KD10 and knockout line KO77 showed higher extracellular peroxidase activity than the wild-type. Gene silencing using RNAi for MG<I>pdc1</I> in the ethanologenic white-rot fungus <I>Phlebia</I> sp. MG-60-P2 is an effective first step in metabolic engineering to produce other chemicals besides ethanol. This high efficiency of transformation and silencing effect will make it possible to cotransform with multiple expression vectors which enhance the minor metabolic pathway or introduce exogenous metabolic reaction in <I>Phlebia</I> sp. MG-60-P2.</P>