Screening of xylose-fermenting yeast
We obtained 72 yeast strains able to ferment xylose
from the approximate 100 natural samples collected.
The ethanol production ability of each isolated strain
was determined using a rich medium with YPX medium
containing 4% xylose. Among the isolated strains, 16
strains produced a significant amount of ethanol from
xylose. To examine the fermentability of xylose, the time
courses of ethanol concentration and xylose consumption
from YPX medium at different temperatures were
monitored by HPLC. We observed that one yeast strain,
strain ATY839 (which was isolated from soil in Kyoto
University) exhibited high xylose fermentability (data not
shown).