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Differences in response of Zymomonas mobilis and Saccharomyces cerevisiae to change in extracellular ethanol concentration

Journal Article · · Biotechnology and Bioengineering; (United States)
;  [1]
  1. Univ. of Melbourne, Parkville, Victoria (Australia). Dept. of Chemical Engineering
In high cell density batch fermentations, Zymomonas mobilis produced 91 g L[sup [minus]1] ethanol in 90 minutes but culture viability fell significantly. Similar viability losses in rapid fermentations by yeast have recently been shown to be attributable in part to the high rate of change of the extracellular ethanol concentration. However, in simulated rapid fermentations in which ethanol was pumped continuously to low cell density Z. mobilis suspensions, increases in the rate of change of ethanol concentration in the range 21--83 L[sup [minus]1]h[sup [minus]1] did not lead to accelerated viability losses. The lag phase of Zymomonas cultures exposed to a 30-g L[sup [minus]1] step change in ethanol concentration was much shorter than that of Saccharomyces cerevisiae, providing evidence that the comparative insensitivity of Zymomonas to high rates of change of ethanol concentration is due to its ability to adapt to changes in ethanol concentration more rapidly than yeast.
OSTI ID:
5209112
Journal Information:
Biotechnology and Bioengineering; (United States), Journal Name: Biotechnology and Bioengineering; (United States) Vol. 43:2; ISSN BIBIAU; ISSN 0006-3592
Country of Publication:
United States
Language:
English