L. Sene et al., Effects of environmental conditions on xylose reductase and xylitol dehydrogenase production by Candida guilliermondii, APPL BIOC B, 84-6, 2000, pp. 371-380
The effects of environmental conditions, namely initial pH (2.5-7.0) and te
mperature (25 and 35 degrees C), on xylose reductase and xylitol dehydrogen
ase levels, as well as on xylitol production, were evaluated. Although the
fermentative parameter values increased with an increase in pH and temperat
ure (the maximum Y-p/s and Q(p) were 0.75 g/g and 0.95 g/[L.h], respectivel
y, both attained at pH 6.0/, 35 degrees C),.the highest xylose reductase ac
tivities (nearly 900 IU/mg of protein) were observed at an initial pH varyi
ng from 4.0 to 6.0. Xylitol dehydrogenase was favored by an increase in bot
h initial pH and temperature of the medium. The highest xylitol dehydrogena
se specific activity was attained at pH 6.5 and 35 degrees C (577 IU/mg of
protein).