Effects of culture conditions on the co-fermentation of a glucose and xylose mixture to ethanol by a mutant ofSaccharomyces diastaticusassociated withPichia stipitis
✍ Scribed by J. M. Laplace; J. P. Delgenes; R. Moletta; J. M. Navarro
- Publisher
- Springer
- Year
- 1993
- Tongue
- English
- Weight
- 377 KB
- Volume
- 39
- Category
- Article
- ISSN
- 1432-0614
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✦ Synopsis
Substrates that contain hexose as well as pentose sugars can form an interesting substrate for the production of ethanol. Pichia stipitis and a respiratorydeficient mutant of Saccharomyces diastaticus were used to convert such a substrate into ethanol under continuous culture conditions. With a sugar mixture (glucose 70%/xylose 30%) at 50 g/l, the xylose was entirely consumed when the dilution rate (D) did not exceed 0.006 h -1 whereas the glucose was entirely consumed whatever the D. The study of influence of initial substrate concentration (So) was p e r f o r m e d at D = 0 . 0 1 5 h -1. Under these conditions the substrate was entirely consumed when its initial concentration did not exceed 20 g/1. With So = 80 g/1 the residual xylose concentration reached 20.5 g/1. At low D or at low So, P. stipitis was the dominant species in the fermentor. Increasing the D or So resulted in the wash-out of P. stipitis mainly b'ecause of its low ethanol tolerance.