Abstract
The product and substrate inhibition effects in the fermentation of xylose by free and immobilized Pichia stipitis in k{cyrillic}-carrageenan gel were determined. The experimental data were obtained from continuous and batch experiments. Process evolution was followed by substrate and product analysis and by a microcalorimetric technique. The results were fitted to Luong's kinetic model. No evidence of substrate inhibition up to 200 gl-1 of xylose were found. From 20 gl-1 of ethanol a marked effect on the productivity as well as on the product yield coefficient was observed. The tolerance of immobilized yeasts to ethanol was lower than that of free cells. Finally, a kinetic expression taking into account the effects of both product and cell concentration on the specific productivity was proposed and validated.
| Original language | English |
|---|---|
| Pages (from-to) | 622-626 |
| Number of pages | 5 |
| Journal | Enzyme and Microbial Technology |
| Volume | 16 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 1994 |
| Externally published | Yes |
Keywords
- Pichia stipitis
- d-xylose
- immobilization
- inhibition
- kinetics
- microcalorimetry