초록
<P><B>Abstract</B><P>A sugar solution containing 31 g l<SUP>-1</SUP> xylose was prepared from the culm of <I>Sasa kurilensis</I> by hydrolysis with 2% sulfuric acid with a liquor-to-solid ratio of 6 (g g<SUP>-1</SUP>) at 121°C for 1 h. During acid hydrolysis, also some byproducts were generated, such as acetic acid, furfural, 5-hydroxymethylfurfral, and low molecular weight phenolics, which inhibit bioconversion of xylose to xylitol. Except for acetic acid, these inhibitors were successfully removed from the hydrolysate by contacting with a steam-activated charcoal (15 g l<SUP>-1</SUP> dose) for 24 h. Bioconversion of the detoxified hydrolysate to xylitol by the yeast, <I>Candida magnoliae</I>, was investigated under various microaerobic conditions. The oxygen transfer rate (OTR) varied from 8.4 to 27.6 mmol-O2 l<SUP>-1</SUP> h<SUP>-1</SUP>. The maximum xylitol yield (0.62 g-xylitol g-xylose<SUP>-1</SUP>) was attained at the OTR of 1.2 mmol-O2 l<SUP>-1</SUP> h<SUP>-1</SUP>. An additional increase in the OTR brought about cell growth, which consumed xylose. A proper control of the oxygen supply is necessary to produce efficiently xylitol from the culm hydrolysate.</P></P>