Anaerobic fermentation of xylose by pichia stipitis: The effect of forced cycling of ph |
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Authors: | Per-Ola Ryding Claes Nlklasson Gunnar Lidn |
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Affiliation: | Per-Ola Ryding,Claes Nlklasson,Gunnar Lidén |
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Abstract: | Xylose fermentation by Pichia stipitis was examined using a two-stage batch process. The cells were first grown aerobically on D-xylose (5 g/L), whereafter additional xylose (10 g/L) was added and fermented during anaerobic conditions (T=30°C). The optimum pH value for a fermentation with constant pH was found to be 4.5 (maximum specific ethanol production rate 0.21 g/(g h). Forced square wave cycling of the pH between 4 and 5, and 3.5 and 5.5 (cycle time 30 min) during the fermentation stage resulted in a fermentation rate lower than the maximum rate, but with unchanged ethanol yields. |
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Keywords: | Keywords: xylose fermentation on-line monitoring periodic operation pH effect |
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