초록
<P><I>N</I>-acetyl-<SMALL>D</SMALL>-glucosamine (GlcNAc) is the building block of chitin, which is one of the most abundant renewable resources in nature after cellulose. Therefore, a microorganism that can utilize GlcNAc is necessary for chitin-based biorefinery. In this study, we report on the screening and characterization of yeast strains for bioethanol production from GlcNAc. We demonstrate that <I>Scheffersomyces</I> (<I>Pichia</I>) <I>stipitis</I> strains can use GlcNAc as the sole carbon source and produce ethanol. <I>S. stipitis</I> NBRC1687, 10007, and 10063 strains consumed most of the 50 g/L GlcNAc provided, and produced 14.5 ± 0.6, 15.0 ± 0.3, and 16.4 ± 0.3 g/L of ethanol after anaerobic fermentation at 30 °C for 96 h. The ethanol yields of these strains were approximately 81, 75, and 82 % (mol ethanol/mol GlcNAc consumed), respectively. Moreover, <I>S. stipitis</I> NBRC10063 maintained high GlcNAc-utilizing capacity at 35 °C, and produced 12.6 ± 0.7 g/L of ethanol after 96 h. This strain also achieved the highest ethanol titer (23.3 ± 1.0 g/L) from 100 g/L GlcNAc. To our knowledge, this is the first report on ethanol production via fermentation of GlcNAc by naturally occurring yeast strains.</P>