초록
Here, it is shown three-step investigative procedures aiming to improve pentose-rich fermentations performance, involving a simple system for elevated mass production by Scheffersomyces stipitis (I), cellular recycle batch fermentations (CRBFs) at high cell density using two temperature strategies (fixed at 30<SUP>o</SUP>C; decreasing from 30 to 26<SUP>o</SUP>C) (II), and a short-term adaptation action seeking to acclimatize the microorganism in xylose rich-media (III). Cellular propagation provided 0.52g<SUB>drycellweight</SUB>g<SUB>RS</SUB><SUP>-1</SUP>, resulting in an expressive value of 45.9g<SUB>drycellweight</SUB>L<SUP>-1</SUP>. The yeast robustness in CRBF was proven by effective ethanol production, reaching high xylose consumption (81%) and EtOH productivity (1.53gL<SUP>-1</SUP>h<SUP>-1</SUP>). Regarding the short-term adaptation, S. stipitis strengthened its robustness, as shown by a 6-fold increase in xylose reductase (XR) activity. The short fermentation time (20h for each batch) and the fermentation kinetics for ethanol production from xylose are quite promising.